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Human Factors Issuesin Handgun Safetyand Forensics

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Human Factors Issuesin Handgun Safetyand Forensics

Hal W. HendrickPaul ParadisRichard J. Hornick

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Library of Congress Cataloging-in-Publication Data

Hendrick, Hal W.Human factors issues in handgun safety and forensics / Hal Hendrick, Paul

Paradis, and Richard J. Hornick.p. cm.

Includes bibliographical references and index.ISBN 978-0-8058-5742-9 (alk. paper)1. Firearms--Safety measures. 2. Pistol shooting--Safety measures. I. Paradis,

Paul. II. Hornick, Richard J. III. Title.

TS537.H365 2007683.4028’9--dc22 2007032787

Visit the Taylor & Francis Web site at

http://www.taylorandfrancis.com

and the CRC Press Web site at

http://www.crcpress.com

DedicationThis work is dedicated to our parents who taught us the value of human life. Harold and Audrey Hendrick, Joseph and Geraldine Paradis, and Clarence and Mary Horn-ick will never know that their respect for truth still influences us and, inadvertently, put us together.

vii

ContentsPreface ......................................................................................................................ixAcknowledgments .....................................................................................................xiAbout the Authors .................................................................................................. xiii

1 An Overview ........................................................................................1

2 Human Factors Causes of Unintentional Shootings ........................... 15

3 History of Firearms ............................................................................ 31

4 Handgun Components and Mechanics ............................................... 47

5 Ammunition ....................................................................................... 83

6 Fundamentals ................................................................................... 105

7 Safety Rules: The Search for Commonality..................................... 127

8 Means of Preventing Access to Home Protection Handguns .......... 135

9 Training ............................................................................................ 143

10 Human Factors and Forensics .......................................................... 161

11 Conclusion and Recommendations .................................................. 177

AppendixACaseStudiesofInadvertentandUnintentionalShootings ......... 185

AppendixBAdditionalInformationfroma

StudyofPhysicsandFirearmHandling ...................................... 193

Glossary .......................................................................................................... 197

References .......................................................................................................... 215

Index .......................................................................................................... 219

ix

PrefaceIn writing this book, our goal was to provide a text that would be a must addition to the personal library of anyone involved in handgun design, handgun training, firearms safety, investigation of shooting incidents, human factors/ergonomics, and

litigation concerning shootings.

When author Paul Paradis, a criminalist for the Colorado State Public Defend-

er’s Office and firearms expert, read an Internet article titled “Human Factors as

a Field” by Richard Hornick, he realized he had found someone with an area of

expertise previously known to him only through experience. He had been unaware

of the formal discipline of human factors. Paul immediately recognized that this

scientifically based discipline was much needed in the understanding of inadver-

tent and unintentional shootings. Paul was aware of psychology being brought into

many civil cases involving accidental shootings, but he was looking for the expertise

that could help determine events in criminal cases in Colorado. Too often, from his

experience investigating hundreds of shootings and testifying as an expert witness

in cases where he was convinced a shooting was unintentional, no expert with a

professional knowledge of human factors and ergonomics was available to provide a

scientific explanation to the jury. Unfortunately, Paul found it was not uncommon for

the defendant in such cases to be convicted of first- or second-degree murder. This

concern is heightened by the fact that conviction of first-degree murder in Colorado

automatically results in a life sentence without parole (for what he and others would

believe to be an accident).

Paul contacted Richard Hornick in California, and Richard in turn put Paul

into contact with Hal Hendrick, as he was living only 60 miles away from Paul

in the Denver, Colorado area. Over the next decade, Hal worked with Paul inves-

tigating cases for the Colorado State Public Defender’s Office, as well as on other

cases involving either civilian or police shootings. Meanwhile, Richard also became

involved in serving as an expert witness in shooting cases.

A result of our collective experience was to identify numerous human factors

safety issues regarding both handgun design and training, and related human behav-

ior in shooting incidents. At the 2003 Annual Meeting of the Human Factors and

Ergonomics Society, the authors held a workshop on the book’s topic. This led an

editor for Lawrence Erlbaum to contact us about writing a book on the topic that

would provide much-needed scientifically based professional information, together

with our individual professional experiences, to those involved in handgun safety

training, handgun design, and litigation involving handguns, including attorneys and

forensics investigators. We concurred that such a book was needed and agreed to

write it. You now have the result.

The book begins with an overview of the problem, including available statistics

on shootings and their limitations, and goes on to describe the discipline of human

factors and ergonomics. The second chapter is a comprehensive review of the scien-

tifically based human factors causes of inadvertent and unintentional shootings that

x Human Factors Issues in Handgun Safety and Forensics

we have encountered in our collective experience with actual shooting cases. To lay the groundwork for understanding the components and mechanics of handguns and the human factors and ergonomics issues associated with them (presented in Chap-ter 4), Chapter 3 provides a historical review of firearms. Chapter 5 gives a detailed

explanation of handgun ammunition and the various human factors and ergonomics

safety problems current ammunition creates. Chapter 6 presents the fundamentals of

shooting and explains how violation of those fundamentals can lead to unintentional

shootings. Chapter 7 covers basic firearms safety rules and their inconsistencies,

which potentially can cause confusion. Chapter 8 discusses means of preventing all

but the intended person(s) from being able to fire a handgun, including the current

smart gun technologies under development. Chapter 9 outlines the importance of

handgun safety training, including supporting rationale, and critically reviews the

various National Rifle Association training programs—which are the most widely

used programs available—and makes suggestions for further improving those pro-

grams. Also covered is the issue of instructor training and needed improvements.

Chapter 10 then goes into the application of the previous nine chapters in forensics,

and covers a number of topics relative to the use of human factors/ergonomics and

safety professionals as expert witnesses.

A major feature of the book is the included DVD, which contains approximately

450 color photos to support the content of the text. We believe this DVD also will be

a very valuable training aid for use in firearms training programs.

xi

AcknowledgmentsWe would like to express our heartfelt appreciation to the many people who contrib-uted to the development of this book. In particular, historian and firearms instructor,

David Willard, for his very substantial assistance in preparing Chapter 3 on the his-

tory of firearms; Royal Antles, for his engineering skills in assisting in the analysis

of several forensics cases and, especially, to the preparation of the graphics in our

figures and DVD photos; and Dan Mariani for the use of his firearms collection in

developing the DVD photos.

In addition, a number of others assisted us in various ways, including lending us

use of their firearms, assisting us with the photographic work, and reviewing selected

chapters in their areas of expertise. Their interest and assistance was of great help:

Charles Kent Clawley, Stephen Cramm, Doug Davis, Don Derby, Robert Dowdrick,

Robert Duncan, Jeff Gauch, Amanda Gillmer, Keith Gillmer, James Gordan, Don-

ald Guetig, Melody Hall, Tony Hecker, Robert Heinrich, Dr. Larry Howard, Brian

Inman, Mike Maguire, John McFarland, Jonathan, Marina, and Michelle Paradis,

Jennifer Shepard, Shane Shepherd, Patrick Smelser, Eric Soltz, Marsha Sprague,

Donald Stafford, and Dan Sullivan.

We also wish to thank the manuscript reviewers, Professor Peter A. Hancock,

Rebecca Larson, and Dr. Richard A. Olsen, for both their very helpful critical con-

structive comments and their support of the project.

Finally, we wish to thank our wives, Mary Hendrick, Mona Hornick, and Susan

Paradis, and Paul’s children, Jonathan, Marina, and Michelle, for their tolerance in

putting up with our long hours away from them while completing this project The

three of us greatly appreciate their acceptance, understanding, and support.

xiii

About the AuthorsHalHendrick is emeritus professor of human factors and ergonomics at the Uni-versity of Southern California (USC) and principal of Hendrick and Associates, a private consulting firm. He is a past chair of USC’s Human Factors Department and

former executive director of the university’s Institute of Safety and Systems Man-

agement. He is a certified professional ergonomist and a diplomate of the American

Board of Forensic Examiners. He holds a PhD in industrial psychology and an MS

in human factors from Purdue University, with a minor in industrial engineering.

He is a past president of the Human Factors and Ergonomics Society (HFES), the

International Ergonomics Association (IEA), the Foundation for Professional Ergo-

nomics, and is a founding member and past president of the Board of Certification in

Professional Ergonomics (BCPE). Hal is a fellow of the IEA, HFES, American Col-

lege of Forensics Examiners, and American Psychological Association, and a charter

member and fellow of the American Psychological Society. He is the recipient of

USC’s highest award for teaching excellence, the IEA Distinguished Service Award,

and the HFES Arnold M. Small President’s Distinguished Service Award, the Jack

A. Kraft Innovator Award, and the Alexander C. Williams, Jr. Design Award. Hal

has over 45 years of experience as a human factors and ergonomics practitioner,

educator, program administrator, and consultant. He has served as an expert witness

in human factors/ergonomics and safety in over 200 civil and criminal cases. Hal

is the author or coauthor of over 200 professional publications and three textbooks,

and has edited or coedited 10 books, including the Handbook of Human Factors and

Ergonomics Methods (CRC Press, 2005). He holds a regular commission in the U.S.

Air Force (Lt. Col., USAF ret.).

Paul Paradis is a criminalist with the Colorado State Public Defender’s Office.

He also is a firearms store owner, gunsmith, and firearms instructor in Colorado

Springs, Colorado. He has trained civilians, law enforcement, and military person-

nel. He is a training counselor with the National Rifle Association (NRA) and trains

instructors in this capacity. He is also a certified pistol, rifle, shotgun, home safety,

law enforcement, and chief range safety officer. Mr. Paradis served in the U.S. Army

Infantry and the Colorado National Guard in both Special Forces and Artillery units.

His skill as a firearm/weapons instructor earned him an active duty Army Commen-

dation Medal. Mr. Paradis’s training and abilities in firearm forensics, mechanics,

and training have qualified him to testify as an expert in both federal and Colorado

state courts for more than a decade. Mr. Paradis continues to assist the military as a

firearms and forensic consultant. He has investigated more than 1,200 shooting inci-

dents, including approximately 400 that he concluded were probably unintentional.

Richard Hornick received his undergraduate degree from Marquette University

and his PhD from Purdue University in experimental psychology. He performed

research with the astronauts for the Apollo Manned Lunar Landing Program while

xiv Human Factors Issues in Handgun Safety and Forensics

at North American Aviation in the early 1960s. He then managed human factors design organizations at Litton Industries and Hughes Aircraft Company for human-integrated designs of advanced navy ships, high-performance aircraft, air defense, air traffic control, sonar, command/control, communication, and transportation sys-

tems. Dr. Hornick became interested in details of firearm design and handling as a

result of his involvement in litigation as a human factors expert witness. Most of his

forensic testimony has been in product liability, workplace injury, and vehicle acci-

dent cases (approximately 200), though he has testified in criminal shooting matters

to assist juries in determining intentional versus inadvertent weapon firing. He is a

past president of the Human Factors and Ergonomics Society (HFES), served on the

HFES Executive Council for over 25 years, and is a fellow of HFES. He also served

on the editorial board of the journal Human Factors for 17 years. He received the

HFES’s Arnold M. Small President’s Distinguished Service Award. He also chaired

the society’s Forensics Professional Group and was instrumental in the development

of several mock trials. He is the author of many professional articles and several

chapters in books. Dr. Hornick is a certified professional ergonomist and a diplomate

of the American Board of Forensic Examiners. He is the head of Hornick & Associ-

ates in Dana Point, California.

1

1 An Overview

THE PROBLEM: INADVERTENT AND UNINTENTIONAL SHOOTINGS

The reader may wonder why society should be sensitive and responsive to the plead-ings of the three authors of this work. There currently are four major alarms sound-ing for gun proponents as well as for people antagonistic to the widespread use of handguns in our society.

First, the growth of gun sales in the United States remains constant. There is no argument against the fact that guns (not only handguns but all types of guns) con-tinue to exhibit record sales, based on whatever speculations a reader wishes to bring to the table. Guns are an inherent factor in our culture. In that regard, it is interest-ing to note that the state of Alaska, as of October 2005, now provides that owners of handguns be allowed to carry concealed weapons without a permit in the seven Alaskan cities where permits formerly were required (Orange County edition, Los

Angeles Times, October 15, 2005). More people now carry handguns in the United States, legally or illegally, than ever before. This is in spite of gun control efforts.

Second, societal concern has grown to outrage for local street-level shootings in which innocent bystanders, including children, are killed or maimed by rival gang members or by police who are engaged in criminal pursuit actions—all victims of inadvertent or unintentional firearms discharges.

Third, there is an increasing awareness that handguns, as effectively as they may

function to propel a bullet with deadly accuracy, often are fired inadvertently, with-

out intention, and without malice or forethought; in other words, accidentally, with

horrendous trauma in domestic circumstances when loved ones die as a result.

Fourth, there is a growing tendency to bring liability lawsuits against gun manu-

facturers on the basis of claimed manufacturing defects and forseeable (but uninten-

tional) misuse. In these kinds of cases, a plaintiff argues not that the product was

manufactured defectively but that it was defective in the manner in which it was

designed and could be (or had to be) operated.

These four alarms should arouse a large community of gun advocates, gun control

activists, parents, law enforcement agencies, and human factors practitioners (huh?)

to rush to the table to promote the design of guns that are resistant to accidental firing

and to improve the effectiveness of training programs relative to their use.

We said “huh?” here in this introduction because the specialized field or sci-

ence of human factors is not an everyday, household expression. As we see later in

this chapter and others, human factors is a scientific discipline that incorporates the

expertise of a variety of related sciences oriented to the improved safety of things

that people use. Firearms are one of those things. With respect to handguns, the

goal is to prevent inadvertent or unintentional shooting of people through improved

design and training.

2 Human Factors Issues in Handgun Safety and Forensics

This chapter provides an overview of the general problem, offers some data, crit-ically examines recorded statistics, and introduces what improvements might well be achieved to reduce inadvertent and unintentional shootings through the application of human factors design principles, guidelines, specifications, tools, and methods. It

also describes the discipline of human factors/ergonomics and outlines the structure

of the remainder of the book.

HANDGUN SHOOTINGS: INADVERTENT,

UNINTENTIONAL, OR INTENTIONAL?

The list of shootings noted later provides us with some perspective about situations

in which we can (probably) determine that a shooting was intended, unintended, or

inadvertent. It should be noted that the authors recognize that criminal law termi-

nology relative to intentional, accidental, involuntary, and unintentional has differ-

ent legal implications in different jurisdictions, further complicated by negligence,

reckless disregard, and other colloquial terms. Because of that, the authors subsume

all of those terms into a more generic set of categories—intentional, unintentional,

and inadvertent. In later chapters, where appropriate, the term “involuntary” also

is used to describe handgun discharges caused by involuntary muscle contractions.

As used herein, intentional refers to a situation where the person purposely shot

someone; unintentional refers to a situation where the shooter intentionally fired his

or her handgun, not intending to shoot someone, but did. Inadvertent refers to a situ-

ation where the shooter did not intend to discharge his or her handgun, but did, and

someone was shot as a result.

Haag (2006, p.333) uses a definition, widely accepted in the firearms world, that

combines our concept of inadvertent with unintentional: “Unintentional Discharge:

The handler of the gun is the source of the discharge. Examples; improper letdown

of a hammer, involuntary/sympathetic discharge during a struggle, slip and fall, etc.”

However, for human factors purposes, it is important to make a distinction between

the two.

Consider the following:

Bang!A gun is discharged, fired, shot. No matter what term we use, the end

result either is relatively benign or it is horrendously traumatic.

Bang! The sound accompanied by many others on a practice firing range. Many

shooters, all wearing ear protectors to muffle the explosions from small to large

handguns, all practicing safe procedures. Fun.

Bam,Bam,Bam!Sounds coming from police weapons being fired at a suspect

of some sort who is firing back at the police. Someone dies. Very bad.

Bang,Bang,Bang,Bang!A police officer fires multiple shots, at night, after

following a suspicious person; the person turns, holding something in his hand.

Now the person is dead. He holds not a gun but a wallet with identification. Very

unfortunate.

Bang,Bam!A teenaged gangbanger sets his sights on a rival, sometimes with

success, sometimes hitting innocent bystanders. The targeted persons and innocents

either die or are seriously injured. Very sad.

An Overview 3

Bang!A college student, depressed by poor grades and a broken romance, holds a gun to his head. The bullet does its damaging job. Intentional? Maybe not?

Bang!A child, curious about the unusual item, picks up a gun lying just in reach by her distracted father, puts her dainty fingers on the trigger, and the bullet’s power

is unleashed in any direction, perhaps striking her father. Traumatic indeed.

Bang,Bang!A furious or jealous spouse confronts his or her mate and threatens

revenge. The gun goes off. Intentional? Inadvertent? The press has an open invitation

for speculation.

Bam! A single shot. Two teenaged friends finding a parent’s gun, looking at it,

knowing that there are no bullets in it, and one suddenly is dead from a bullet to his

brain. “We didn’t know it was loaded” is the common refrain.

Bam!Another single shot. This time from a weapons-savvy person, cleaning his

or her gun, knowing full well that there was no round in the chamber. However, the

bullet proves otherwise by entering the leg of the weapon cleaner or, perhaps, enter-

ing the body of a loved one.

Bang,Bang,Bang!A driver, momentarily distracted, accidentally pulls in front

of an adjacent car. Within seconds, that driver is shot at by the driver of the second

car in another incident of road rage.

Bang,Bam!Again at a firing range, this time by instructors training people how

to use a handgun properly.

Bam,Bang!“Happy New Year” or “yippee” for some kind of holiday, and shots

are fired into the air. Occasionally a bullet coming back down hits someone, some-

times fatally. Is this classified as a homicide or an accidental death? Would we call

this an intentional or an inadvertent act on the part of the shooter? How would the

death be documented? Many jurisdictions differ in opinion.

CONFUSION IN CATEGORIZING

In most of the instances listed previously, the nature of the shootings—whether

intentional, unintentional, or inadvertent—is clear because of the way we have

described them. In some others—the apparent suicide, the spousal killing, the police

officer shooting multiple times at an unarmed person, the gangbanger who hits inno-

cent bystanders, and the drunken celebrator—we are presented with the problem

addressed by this book. The problem to be addressed intensively in this work is that

guns are frequently fired inadvertently—far too frequently from many perspectives.

The problem is that handguns often are fired inadvertently, or someone is shot unin-

tentionally, because of questionable design features, lack of proper training, and the

lack of safeguards that could be added to, or become an inherent part of, the firearm

itself—at least in future firearms.

In the apparent suicide described earlier, there is the matter of whether this truly

was a deliberate act. We would tend to think at least probably—the elements are all

there. What if we were to learn that his roommate subsequently said that the victim

had done this same behavior (without pulling the trigger) a number of times in order

to scare himself out of actually doing it by imagining what it would be like to take

his own life? What if we found out that the trigger only required 2.5 pounds of force

to fire the weapon? Inadvertent? Might well be.


One spouse kills the other. Newspaper articles would cite the history of calls made to the home for domestic disturbances. Neighbors would be quoted as hearing many arguments with loud verbal threats. Our presumption might well be that one killed the other intentionally. Can we discount the possibility that the shooter, angry again, believed that there was no round in the chamber, or that he thought the safety was positioned properly and was just meaning to frighten the spouse? Would we believe the emotional pleadings of the distraught shooter? How would this shooting be classified—intentional, accidental? Is there some nebulous category officially for-

matted for probably intentional? No. Or, if the threatened spouse picked up the gun

in self-defense but without the real intention of firing it, and the gun fired because

the trigger force was light and the spouse held the weapon too tightly, moving the

trigger just enough? What if one person grabbed at the gun in the hands of another

and hit the trigger, causing it to discharge? Can this incident easily be depicted as

intentional or inadvertent?

In the previously described instance of the police officer, it seems clear that he

intended to shoot even though the suspicious person was unarmed (finding that out

after the fact). Here the stress of the situation and poor visibility due to inadequate

lighting may well have led the officer to believe that his life was in danger. Beyond

that, however, many experiences are described in such shootings that the officer only

intended to fire once, perhaps twice, not the six or seven shots that might have been

fired. Is this classified as an intentional or an inadvertent shooting? Intentional at

first, but inadvertent after the first shot or two?

Then, on a hot night, seeking revenge for something done to a fellow gang

member, a car cruises up to a group of young persons seemingly from the rival

gang. Hyped up, possibly on drugs, a semiautomatic weapon is fired, the group scat-

ters, none of them is hit, but one bullet inexplicably finds its way through a child’s

window, killing her instantly. How do we classify this event? Intentional shooting?

Of course. Unintentional death? Of course, again. How does this get handled and

become understandable in any database?

Finally, the revelers who shoot their guns into the air present us with yet another

challenge. Was the resulting fatality from a rapidly falling bullet accidental, or

unintentional, or even intentional? Some might opine that this was intentional if

the shooter was well advised that doing what he did was highly dangerous and life

threatening. Certainly, reckless behavior we might admit. How is the death classi-

fied? Hmm . . . she died of reckless disregard.

The reason for belaboring these events is to demonstrate several things.

First, it is difficult to find meaningful statistics about shooting deaths with

handguns that can tell us much about anything, except that the number of lives lost

or injuries experienced in shootings is great. Certainly, we can count the numbers

of deaths and injuries by age group. We can tabulate the differences between age

groups in which shootings are the prime cause of death. We can compare shooting

deaths in different regional areas, whether parts of the nation or different parts of

individual cities. We can study trends in the comparison of homicides accomplished

by guns, knives, and other means. These data can be readily obtained from the U.S.

Department of Justice, Bureau of Justice Statistics.

An Overview 5

Second, we might well be able to distinguish most shootings as intentional, unintentional, or inadvertent; however, there are many shootings that may really be inadvertent or unintentional, that are assumed to be intentional. Such claims can come from vindictive spouses or police officers under stress. It also is possible that

reported instances of inadvertent weapons firing were, indeed, intentional.

Third, where there are descriptive statistics, they hide the severe and real trauma

that is thrust upon the victims’ families and friends, whether they have been killed

intentionally or accidentally. When a shooter has intentionally killed, the conse-

quences can be severe if caught and convicted. In the case of an inadvertent or unin-

tentional shooting death, in addition to the survivors of the victim, the person handling

the weapon will likely suffer severe emotional distress, perhaps for a lifetime.

We also recognize that shooting statistics indicate increases or decreases in

homicides due to gunshots in ways that suggest that such are rising or falling (in

various age groups and locations, for various periods of time, etc.). A good source of

such information about homicides is the Bureau of Justice Statistics (cited earlier).

A visit to that Web site is worthwhile, and some data suggest that homicides due to

guns decreased over several years before slightly rising again. Two considerations

need to be pointed out here. First, the data are from documented homicides (which

do not distinguish between inadvertent or unintentional and intentional shootings);

and second is the statement on the Web site (www.ojp.usdoj.gov/bjs/ as of January

1, 2007) to this effect: “Over two-thirds of the spouse and ex-spouse victims were

killed by guns” (again without differentiation between intentional and unintentional

or inadvertent shootings).

INADVERTENT AND UNINTENTIONAL HANDGUN SHOOTINGS

Are accidental gun deaths as rare as they seem? This was the question formally

addressed by several researchers at the University of Miami School of Medicine

(Schaechter, Duran, DeMarchena, Lemard, & Villar, 2003). Acknowledging that the

recognized general rate for pediatric deaths by inadvertent and unintentional shoot-

ings in the Miami-Dade region hovers around 2.8%, their investigation documented

the shortcomings in death versus motive characterization as being faulty, with the

likelihood that the incidence of unintentional and inadvertent pediatric firearm

deaths is significantly underreported by the medical examiner’s office.

In another study published by the American Academy of Pediatrics (2000),

many findings relative to the interests of this book were identified. For example,

in 1997, there were over 32,000 gun-related deaths in the United States, of which

there were some 4,223 adolescents younger than 20 years of age. In 1996 and 1997,

approximately two-thirds of adolescents between the ages of 15 and 19 used hand-

guns; however, that study did not attempt to identify the approximate percentage of

unintentional or inadvertent firings. Even if we recognize an approximate rate of 3%

of shooting fatalities to be inadvertent or unintentional, this means that, minimally,

three people die each day from accidental shootings. The National Center for Vital

Statistics reported in 1999 that the number of documented unintended shootings was

824.


POLICE EXPERIENCE WITH INADVERTENT

AND UNINTENTIONAL SHOOTINGS

It would seem that police officers, who should be highly trained, would essentially

be immune from inadvertent firing, but even here inadvertent shootings occur at

rates perhaps surprisingly high. A study conducted by and reported in the August 17,

2006, Orange County edition of the Los Angeles Times concluded: “In 350 incidents

since 1985, officers shot selves or one another nearly as often as they were hit by

suspects . . .” (Glover & Latt, 2006, p. B-1–B-5). The study reports that most of such

shootings occur while pursuing suspects or cleaning weapons. During the 20 years

studied, there were 90 officers shot by suspects and 68 shot by fellow officers; how-

ever, the news article reports a number of shooting incidents that illustrate the wide

set of circumstances in which inadvertent discharges occur. Examples are cited such

as: (a) an off-duty officer shooting himself in his leg sitting behind his desk while

contemplating a mathematical problem; (b) another accidentally shot his girlfriend

in her leg while trying to get a round out of his pistol as a souvenir; (c) two officers

fired their weapons accidentally while handling them as they watched themselves in

a mirror; (d) another fired his .38-caliber gun while demonstrating trigger force to

his fiancée (he thought there were no rounds left in the chamber, but . . .); fortunately

the bullet struck a wall. The article relates other incidents in which alcohol and/or

horseplay apparently were factors in unintended discharges.

It should be noted that many police departments refuse to voluntarily release

any information to the public on accidental shootings by officers. Consequently, the

actual number of incidents similar to those described is likely much greater than

available statistics show.

COLLECTIVE JUDGMENT

It is the collective judgment of the authors that inadvertent firing of handguns is far

more prevalent than any statistical database can provide information about. Vari-

ous agencies (such as hospitals, medical examiners, police commissions, and sheriff

departments) can compile the numbers when someone is injured or killed by a hand-

gun. But, those same agencies have no way of collecting statistical information for

weapons accidentally discharged when they are unreported; and there is little or no

motivation for a person to report that he or she accidentally fired a weapon.

Indeed, the authors collectively have been involved in numerous instances

defending an accused prior to trial, or testifying at trial to assist a jury in determin-

ing whether a particular shooting could be found to be intentional, unintentional, or

inadvertent. In many instances, a shooting that initially appears to be intentional is

determined to be inadvertent or unintentional when all the factors are analyzed and

interpreted. (In addition to those cited throughout the text, see Appendix A for other

examples of such cases.)

One of the authors (Hornick) had the experience of accidentally firing a .22-caliber

target pistol and nearly hitting his 6-year-old son. This happened in a forested area

intended at the time for small target shooting. This author had reloaded the magazine,

believing that the safety was set to prevent the pistol from firing. In walking with his

An Overview 7

son along the firing area, the gun discharged. The problems? First, the author should

never have had his finger on the trigger at that moment (he had received no special

training prior to that incident). Second, the lever to activate a safe condition swings

alternately between a red and white spot; when in either position, the respective spot

is covered by the lever, thus leaving either a red or a white spot exposed. How does

one, aside from studying the manual or frequent use, determine if the exposed red

means that the gun is off and safe, or hot and ready to fire? Does white mean that the

gun is in a safe mode or ready to fire? As we discuss in Chapter 4, it depends on the

particular semiautomatic one is using.

IMPLICATIONS

Even if consistent banks of data recording and formatting existed across the many

types of jurisdictions and agencies, the information would be difficult to interpret

(except, perhaps, to conclude that there are a lot of people dying from firearms). As

in other kinds of data, in analyzing the frequency of intentional versus unintentional

or inadvertent shootings, the problem of false positives and false negatives is encoun-

tered. Death from shootings is problematic in that certain kinds of homicides and

suicides seem indisputable as being intentional for the most part; yet there certainly

are false positives in that many deaths are known to be unintentional after being

subject to greater scientific scrutiny. On the other hand, some deaths not considered

to be intentionally caused may well have been, so the element of false negatives

needs to be considered as well. From the authors’ collective experience, the problem

of false positives exceeds that of false negatives—that there are substantially more

deaths incorrectly designated as intentional than the other way around.

In injuries from shootings, we can expect the phenomena of false positives and

false negatives to be less confusing in that the person injured can add information to

help clarify how the shooting should be classified. Still, there also is room here for

some element of uncertainty.

Suicide statistics by gunshot, as we illustrated at the onset of this chapter, also

can be muddied by the false positive element, though probably not very extensively.

And how does the set of deaths by playing Russian roulette get categorized—inten-

tional or unintentional (or recklessness or just plain stupidity)?

Analyzing any data within the police community is even more problematic in

determining the frequency of inadvertent weapon firing for either deaths or injuries.

There are many instances where the officer would not have shot had he or she known

that a suspect was not carrying or threatening him or her with a firearm of his or

her own. Are such cases to be interpreted as intentional or unintentional? There are

instances where an officer wished to shoot once or twice, but multiple shots were

fired, perhaps due to the stress environment or the physical reality that the double-

action handgun had a high trigger force for the initial pull and a much smaller trigger

force for subsequent activation. How to classify these instances? Finally, there are

known cases of abuse of power where an officer was found to be guilty of repeated

and unnecessary firing (essentially, murdering a victim). Even here, was such behav-

ior perhaps unintentional or involuntary if it could be determined that the officer had


a set of precursor conditions that could scientifically be analyzed and then attributed

to those conditions on some probabilistic basis?

In cases where criminal intent is in contention, the authors believe that it is

essential to probe as much scientific data pertinent to the events as possible. As we

discuss in Chapter 10, analyses using all of the various applicable forensic sciences

are critical to help determine the facts of a shooting, including by human factors pro-

fessionals. There is much information in the realm of human factors and ergonom-

ics regarding the potential ingredients in a shooting matter. Much is known about

muscle strength, habit patterns, expectancies, perceptual processes, decision mak-

ing, reaction time, lighting and visibility, sensory processes, behavioral tendencies,

effects of stress, fatigue, and various other human capabilities that can contribute

substantively and critically to the understanding of the key actions involved.

HUMAN FACTORS/ERGONOMICS

DESCRIPTIVE DEFINITION OF HUMAN FACTORS/ERGONOMICS (HF/E)

The International Ergonomics Association defines human factors/ergonomics (HF/

E) as “the scientific discipline concerned with the understanding of the interactions

among humans and other elements of a system, and the profession that applies theo-

retical principles, data and methods to design in order to optimize human well-being

and over-all system performance.” The IEA goes on to note that professional prac-

titioners of HF/E “contribute to the planning, design and evaluation of tasks, jobs,

products, organizations, environments and systems in order to make them compat-

ible with the needs, abilities and limitations of people” (International Ergonomics

Association, 2000, p. 5).

The Board of Certification in Professional Ergonomics (1999) defines the disci-

pline as “a body of knowledge about human abilities, human limitations and other

human characteristics that are relevant to design” (Chapanis, 1988). Ergonomic

design or engineering is the application of human factors information to the design

of tools, machines, systems, tasks, jobs, and environments for productive, safe, com-

fortable, and effective human functioning” (Chapanis, 1988).

HISTORICAL BEGINNING OF HUMAN FACTORS

Although human factors research can be traced back to the early 1900s, it was not

until the 1940s that human factors emerged as a formally identified, scientifically

based discipline. In the United States, human factors began during World War II

to explain why so many military aviation accidents were being attributed to pilot

error. The finding by engineering psychologists was that the causative problem was

engineering design error that induced human error because it demanded perfor-

mance that exceeded human limitations and capabilities. This finding led to human

factors research to develop human-machine interface technology (then called man-

machine). Specifically, the concern was with the design of controls, displays, work-

space arrangements, and seating to reduce human error, decrease human workload,

and enhance human comfort and productivity. One early outcome of the resultant

development and application of human-machine interface technology was to greatly

An Overview 9

improve aviation safety—an outcome society has benefited from ever since. (Ameri-

can Psychological Association, n.d.). In the United States, this discipline became

known as human factors.

In Europe and Japan, concerned with rebuilding their industries after World War

II, studies of the human operator led to a similar development of human-machine

interface technology—particularly as applied to the biomechanical and anthropo-

metric design aspects of controls and workspace arrangements in industrial systems.

In Japan and Europe, the discipline became known as ergonomics, meaning the

study of work.

Today, human-machine interface technology enables the enhancement of safety

and usability of a broad spectrum of human-machine systems via design, including

all forms of transportation, industrial and office equipment and workstations, and

consumer products. Today, the terms human factors and ergonomics are formally

recognized by the IEA as being interchangeable (Hendrick, 2000a).

HUMAN-SYSTEM INTERFACE TECHNOLOGY

As a science, human factors/ergonomics is concerned with developing knowledge

about human capabilities, limitations, and other characteristics as they relate to the

design of the interfaces between humans and other system components. This sci-

entifically developed knowledge, in turn, is used to develop Human-System Inter-

face Technology (HSIT). This technology takes the form of HF/E design principles,

guidelines, specifications, methods, and tools. As a practice, HF/E professionals

apply human-system interface technology to the design or modification of systems to

enhance safety, health, comfort, and performance, including productivity and qual-

ity. The overall societal goal of HF/E is to develop and apply human-system interface

technology to improve the quality of human life. This is achieved through applying

HSIT to the analysis, design, test and evaluation, standardization, and control of

systems (Human Factors and Ergonomics Society, 1999).

Today, HSIT has at least five identifiable major components: human-machine

interface technology or hardware ergonomics, human-environment interface technol-

ogy or environmental ergonomics, human-software interface technology or cognitive

ergonomics, human-job interface technology or job design ergonomics, and human-

organizational interface technology or macroergonomics (Hendrick, 2000b).

Human-machine interface technology consists of the design principles, guide-

lines, specifications, methods, and tools for designing hardware, such as machines,

tools, and other consumer products, to enhance their usability, safety, and comfort.

As such, this technology is particularly important to improving handgun design,

as well as understanding how HF/E deficiencies in the design of specific handguns

can contribute to unintentional shootings. This is discussed more specifically and

extensively in Chapter 4.

Human-environment interface technology is concerned with the effect of envi-

ronmental factors, such as temperature, illumination, noise, and vibration, on human

performance. Environmental extremes can cause degradation in human perfor-

mance, including the mishandling of handguns and unintentional shootings.


Human-software interface technology, or cognitive ergonomics, is concerned with how people think and process information and the design of software systems that are compatible with the way people think. How people think and process infor-mation is important to both handgun design and training.

Human-job interface technology deals with the science of job design to ensure that workload is appropriate and that jobs are intrinsically motivating. This technol-ogy is particularly important to the issue of instructor job design and the related larger issue of firearms training systems design, as is discussed in Chapter 9.

Macroergonomics is concerned with the design of overall systems to optimize sys-

tems effectiveness. It is a top-down sociotechnical systems approach to the design of

work systems (Hendrick & Kleiner, 2001, 2003). As is discussed in Chapter 9, macro-

ergonomics is particularly relevant to the overall design of firearms training systems.

A FINAL THOUGHT IN HEADING INTO THE REST OF THE BOOK

When asked to describe what the field of human factors is to a court of law when

testifying as an expert witness, a brief and simple description is necessary. Author

Richard Hornick typically responds with something like: “Human factors is a pro-

fession which is comprised of many scientists (such as psychologists, engineers,

medical doctors, physiologists, computer specialists, and others) who have the com-

mon objective to design things and procedures that humans use or maintain so as

to be safe and efficient. And, that this objective applies to everything that humans

interact with: aircraft cockpits, transportation systems, production machinery, office

equipment, controls, displays, walkways, stairs, agricultural equipment, and com-

mon items in the home.”

What does the human factors specialist have to offer regarding handguns? We

first can answer what it does not have to offer relative to handguns. As with any sci-

ence, it does not take an advocacy position relative to the Second Amendment on

either side of the arguments pertaining to gun ownership and/or gun control. Guns

are ubiquitous in the U.S. culture, for better or worse. In that sense, it is a worthy

objective to apply human factors principles relative to the use, safety, and effective-

ness of handguns and their companion aspects, such as warnings, instruction manu-

als, training programs, and the ultimate prevention of inadvertent activation.

Handguns are effective in general; that is, they are accurate (within limits) when

aimed carefully and steadily. The authors were among four writers of an article

published in Ergonomics In Design (EID), an application-oriented publication of the

Human Factors and Ergonomics Society (Hancock, Hendrick, Hornick, & Paradis,

2006). Acknowledging that reality, the authors also pointed out in the EID article

the areas in which the field of human factors can improve gun safety, especially

oriented toward inadvertent shootings. Briefly, and to be explored at greater length

elsewhere in this book, these areas include such factors as trigger pull forces, hand-

grip characteristics, sighting/aiming devices, magazine release features, eliminating

a round remaining in the chamber or preventing its firing, consistency in safety sta-

tus information and clarity of use, positive indication of a cartridge in the chamber,

and the improvement of training programs and training instruction. See Table 1.1

An Overview 11

for a summary of some of those characteristics or features and the implications for human factors application.The human characteristics involved are contained in several dimensions:

Psychological—for example, cognitive skills, perception, learning, reaction time, expectanancies, information processing, decision making, motivation, and stress.

Physiological—for example, vision, audition, tactile sensations, fatigue, drug, and alcohol effects.

TABLE 1.1.

Firearm characteristics and human factors implications

Feature Characteristic Implication

Trigger pull or force May range from 1 to 2 lbs. hair trigger to 12+ lbs.; will vary from hard to soft pull in double-action.

Low force can cause inadvertent firing; large force may make it

difficult for some to use and/or

affect accuracy; variability

may induce inadvertent firing.

Handgrip Vary considerably in size and

shape for different purposes.

Fit should be personally made

for optimal comfort, handling,

and accuracy.

Sighting device Often two pieces, one at muzzle

end of barrel and one at rear

end, but many different

designs; some are adjustable

L-R (windage) and/or up-down

(elevation).

Variations in sighting devices

cause negative transfer of

training, resulting in initial

loss of accuracy until user

becomes familiar with sighting

characteristics.

Magazine release

(semiautomatics)

Permit extraction of bullet

magazine. Vary widely in

location and in direction of

movement to activate release.

Important for disarming gun.

Confusion about manner of

releasing magazine can lead to

accidental discharge.

Bullet in chamber Some semiautomatics fire with

the magazine out if a bullet is

in the chamber; others do not.

No positive indicator. Some

chambers permit limited

visibility of cartridge; others

do not.

Accidental discharge is possible

when a user has released the

magazine and believes the

firearm cannot be fired or that

a bullet is not present. Need

positive tactile indicator of

bullet in chamber.

Safeties Not present on all firearms. Are

intended to keep firearm from

discharging if dropped. Differ

greatly in location, movement,

and coding.

User may put the safety on but

instead enable the firearm to

fire. User may believe that a

firearm is safe when it actually

will discharge.

Movement Firearms can exert forces upon

the hand beyond those

expected by weight alone,

which can overcome trigger

pressure needed to fire.

Overcoming inertia to bring

moving handgun to a stop can

cause inadvertent discharge.


Anthropometric—for example, body size, reach, muscle strength.Much more is said about these characteristics as related to handgun safety and foren-sics in Chapter 2 and elsewhere.

STRUCTURE OF THE BOOK

Chapter 2 discusses aspects of human behavior that, in interacting with the situation, handgun, and past experience, can cause a person to either unintentionally discharge a handgun or fire the handgun in an unintended direction, thus injuring or killing

another person. Included are the nature and performance effects of stress, fatigue,

startle, divided attention, loss of balance, sympathetic contraction, involuntary trig-

ger pull, alcohol, drugs, cost of compliance, design-induced human error, and lack

of training.

Chapter 3 provides a history of the development of firearms. It is intended to pro-

vide the reader with a background for understanding the design of current handguns

as well as older ones still in use.

Chapter 4 describes in detail the components and mechanics of both revolv-

ers and semiautomatics, including the variations among handguns. Human factors

safety issues related to the design of the various handgun components and mechan-

ics are highlighted throughout the chapter, and then summarized at the end by major

underlying issues.

Chapter 5 describes the various types of ammunition and their uses. Particular

emphasis is given to the human factors safety issues related to ammunition, such

as lack of discriminability and confusing nomenclature systems, which can result

in placing the wrong ammunition in a given handgun, and safety issues related to

ammunition manufacture and storage.

Chapter 6 describes the fundamentals of safe and accurate operating of a hand-

gun, including proper grip, stance, breath control, sight alignment, trigger control

and follow-through. How failure to execute properly each of the fundamentals can

lead to unintentional discharge or inaccurate aiming of the handgun, and possible

injury to others or to oneself, is described.

Chapter 7 explores the safety rules advocated in various NRA and other training

courses and manuals, and their lack of uniformity. Problems with safety rules and

their potential safety consequences are highlighted, as well as their value.

Chapter 8 covers the various means for preventing access to handguns, including

external methods, such as trigger locks and lock boxes, and various internal methods

for enabling only the intended user of the handgun to be able to operate it, such as

magnetic, grip, and radio frequency identification (RFID) methods currently under

development. Research is cited that highlights the importance of preventing access

to handguns, especially by young children.

Chapter 9 deals with the extremely important issue of handgun safety training.

The rationale and evidence for requiring testing and certification in order to use a

handgun is given. Major existing training programs are described briefly, including

their strengths and deficiencies. The authors’ recommendations for the content of a

home defense handgun training course, as well as refresher training, are outlined.

Problems with instructor selection, training, and certification are noted, as well as

An Overview 13

the need for a professional association of firearms instructors. The need for taking a

true macroergonomics or systems approach to the design of the total firearms train-

ing system is emphasized.

Chapter 10 deals with the use of human factors/ergonomics professionals as con-

sultants and expert witnesses in shooting cases. Arguments supporting the value and

use of HF/E expert testimony are given, as well as rebuttals to challenges to the use

of HF/E experts. Sources for identifying qualified HF/E experts are provided. Other

forensics disciplines involved in analyzing shootings that may provide the human

factors expert with useful information are noted. Finally, other human factors issues

to consider in forensics, not previously covered, are described.

Chapter 11 presents a final set of thoughts and provocations for the legal com-

munity and the entire community of users of guns—instructors, police officers, ordi-

nary citizens, and especially those interested in pursuing studies and research aimed

at reducing the occurrence of inadvertent and unintentional shootings.

Photos on a DVD. A DVD containing over 450 photos is provided with the book.

These photos are cited in the text, where appropriate, to aid in further understanding

the text. This DVD also is intended as a training aid for firearms training courses.

A description of each cited DVD photo, sometimes with a brief explanation, is pro-

vided at the end of the applicable chapter.

Actual forensics cases are described throughout the book to illustrate and help

explain many of the human factors safety issues covered. Twelve additional cases

are included in Appendix A. Supplemental information from a study of physics and

firearm handling is provided in Appendix B.

15

2 Human Factors Causes of

Unintentional Shootings

INTRODUCTION

Humans interact with handguns in a variety of environmental situations, under vari-ous physiological, cognitive, and emotional states, and with varying degrees of hand-gun safety training and experience. The purpose of this chapter is to discuss these conditions as they affect and degrade human performance, thus potentially leading to unintentional shootings. In particular, those factors that the authors have expe-rienced in their research and investigations that have actually led to unintentional discharges and serious injury or death are discussed in depth.

STRESS

As noted by McGrath (1976, p. 1352), “A potential for stress [exists] when an envi-ronmental situation is perceived as presenting a demand which threatens to exceed the person’s capabilities and resources for meeting it, under conditions where he expects a substantial differential in the rewards and costs from meeting the demand versus not meeting it.” Perhaps the most common situation in which persons unin-tentionally discharge a handgun is when they are in the kind of situation described by McGrath. Included would be when there is a suspected intruder in their home, a highly emotional domestic situation is occurring, or an argument or fight with

another person or persons is taking place. In short, these occur when a person’s

welfare is perceived as being threatened. Thus, understanding the nature of stress—

including its physiological, cognitive, emotional, and resulting behavioral effects—is

essential to understanding why many unintentional discharges and resultant injuries

and deaths occur each day.

PHYSIOLOGICAL NATURE OF STRESS

The common human physiological responses to acute stressful situations first were

documented by Selye (1936), an endocrinologist, who was the first to label these

responses as stress. He defined stress as a reaction to noxious events, which he defined

as stressors. These common physiological stress responses often are referred to as

the fight-or-flight physiological alert response. When threatened, the body automati-

cally prepares to defend itself by either fighting (an approach response) or fleeing

(an avoidance response). A bodily reaction occurs (described physiologically as a

sympathetic-adrenal medullary neuroendocrine system response), increasing one’s

strength and causing the individual to tense his or her muscles (Selye, 1976). Included

are increased heartbeat, labored breathing, and trembling (Rachman, 1983).


In addition to fight or flight, we also would note that a person, not knowing what

to do, might simply freeze. It is not unusual to read or hear about situations in which

a person continues to press down on an accelerator pedal when the proper response

would be to step on the brake pedal in a runaway automobile. For gun handling, such

freezing might result in a person being either unable to fire a weapon when threat-

ened or, conversely, continuing to squeeze the trigger even after the last cartridge is

fired.

One effect of the increased muscle strength and tensing of one’s hand and finger

muscles is that it can cause a person to hold a handgun too tightly. If one’s finger is

on the trigger, just moving the handgun and overcoming the inertia to cause it to

stop will result in a further tightening of the fingers, including the trigger finger, thus

inadvertently causing the handgun to fire. More is said about this later in Chapter 4,

including an actual case.

COGNITIVE RESPONSES TO STRESSFUL SITUATIONS

Related to the underlying physiological responses are common cognitive responses.

These include the following.

Narrowed attention. In order to cope with the input overload of an acute threat

situation, a person develops a form of tunnel vision and attends only to the most

obvious cues in the threat situation, often ignoring or delaying attention to peripheral

cues that may in fact be highly relevant to the situation (e.g. see Combs & Taylor,

1952; Easterbrook, 1959). In a case investigated by two of the authors (see Paradis

& Hendrick, 2001), a young woman, whom we call “Betty,” and a good male friend,

herein called “Bob,” were holed up in a motel, hiding from the woman’s boyfriend,

a drug dealer with a history of violence, who was angry with Betty for having taken

some of his money. The boyfriend found them and was banging on the motel door.

Sally pleaded with Bob to tell her boyfriend that she was not there with him, but Bob

reacted to the acute stress situation by simply freezing and not saying or doing any-

thing. Betty was holding a semiautomatic handgun that she had taken out of her purse

as soon as her boyfriend started knocking on the motel door and calling her name.

As her boyfriend continued calling for her and banging on the door, Betty’s attention

was focused on the door and not to how she was handling the semiautomatic.

Poor judgment. As a result of the previously mentioned tunnel vision and inat-

tention to peripheral cues, and related degraded vigilance, one’s problem-solving/

decision process becomes distorted, resulting in poor judgment (Wachtel, 1968). In

the case described earlier, Betty thought that simply having Bob say she was not

there with him would cause her boyfriend to leave. She also had thought (mistakenly,

of course) that going to a local motel, where she left her car parked in front, would

provide an adequate hiding place from her boyfriend.

Performance rigidity. Generally, persons tend to stick to a particular learned

response even when it clearly no longer is appropriate (to an observer not under

stress) (Staw, Sandelands, & Dutton, 1981). In our Betty and Bob case, Betty kept on

pleading with Bob to say she was not there when Bob clearly was not able or willing

to speak up. And even if Bob had, Betty’s boyfriend was not going to be deterred

from checking the room out himself—especially because Betty’s car was in front!

Human Factors Causes of Unintentional Shootings 17

EMOTIONAL REACTIONS

Fear, anxiety, and frustration. Understandably, acute stressful situations, such as those described earlier in which a person might unintentionally fire a handgun, also

elicit emotional reactions, such as fear, anxiety, and frustration (Driskell & Salas,

1991). These emotional reactions in acute stress situations can, and often do, inter-

act with the other stress responses, such as the tensing of muscles described earlier

(including hand and finger muscles) and cognitive responses. This can result in the

unintentional firing of a handgun, even by highly trained police officers, never mind

a layperson who uses a handgun infrequently or lacks proper safety training. In a

sting case, a police officer approached a car to make a drug bust in which a fellow

undercover officer was in the back seat with the drug dealer. The officer was very

fearful that the drug dealer might have a gun and that his fellow officer’s life was in

danger. The officer stuck his hand with his semiautomatic into the car window and

the gun immediately discharged. [Note: because this phenomenon is so well known,

a basic safety rule, discussed in Chapter 6 (and often violated for reasons discussed

later in Chapter 4) is to never put one’s finger on the trigger until you intend to actu-

ally pull the trigger.]

Distorted perception. A related emotional/cognitive response is to misperceive

a situation as threatening when, indeed, it is not (e.g., see Gleen, 2007). In a case

investigated by one of the authors (Hendrick), a large man holding a car key attached

to a backpack lock, with the key protruding from his hand clenched around the lock,

approached a woman at night in a grocery store parking lot to ask her if she could

give him change for a dollar bill. The woman interpreted the key as a knife blade

and started yelling hysterically that he had a knife and she was being attacked. Not

being able to calm her, the man ran away, but later was charged with attacking her.

No knife was ever found, and, following Hendrick’s report, the case eventually set-

tled. In another case in which human factors testimony was presented (Hornick), a

police officer shot and killed an unarmed male at a motel at night. The police officer

believed that the male person, who was carrying supplies for his infant daughter, was

carrying a gun. Lighting conditions as well as the emotionally loaded situation con-

tributed to this unfortunate misperception and human death after the person turned

to face the officer, all in innocence.

Priming. Related to distorted perception is the phenomenon of priming. If

through a briefing or other source, the person anticipates a particular contextual

situation, it will increase the likelihood that the person will perceive the actual situa-

tion, including objects in the situation, the same way, even if it is inaccurate (Palmer,

1975). Thus, if one has been led to expect to be threatened by someone with a gun

in a stressful situation, an object in his or her hand is more likely to be seen as a gun

than if there had been no priming. For example, in a recent highly publicized case in

Denver, Colorado, during an apartment raid of a suspected drug lab, a police officer

interpreted the Coke can in the hand of an older man who was sitting in a chair as

a handgun, and promptly shot and killed him. In fact, the apartment was not a drug

lab. Priming may well have been a factor in the officer’s misperception.


CHRONIC STRESS

Aside from stress caused by acute stressful situations, such as threatening situations, we all have some background level of chronic stress. This form of stress takes two major forms: self-induced lifestyle stress and residual stress. What is particularly important about this form of stress with respect to unintentional discharging of a firearm is that high levels of chronic stress can reduce the person’s ability to cope

effectively and safely with acute stressors when such conditions occur (Schaubroeck

& Ganster, 1993).

Self-induced lifestyle stress. This form of stress results simply from coping with

the daily hassles created by the lifestyle we have intentionally or unintentionally

imposed upon ourselves. Some people choose to live a lifestyle that creates relatively

few stressful situations on a day-to-day basis, whereas others of us do just the oppo-

site. Also included in this category is cyclic stress, imposed by situations that occur

on a predictable, recurring basis. For example, come April 15th of each year, we all

have to file our federal income tax returns. If we have kept good records and orga-

nized our receipts and so forth during the year, preparing our tax return can be rela-

tively unstressful; alternately, if we have not, it can be a rather stressful experience.

Residual stress.We all carry around some old baggage in such forms as guilt,

feelings of inadequacy, anger, and so forth that we picked up in the process of grow-

ing up. For some, this old baggage is rather light. For others, however, it can be very

heavy, thus causing the person to have a high level of chronic stress.

Again, the importance of chronic stress for our discussion is that it can reduce a

person’s ability to cope effectively with acute stressor situations, such as when one’s

welfare is being threatened, and thus can be an underlying factor in unintentional

firearm discharges.

Environmental Stress. Extremes in various aspects of one’s physical environ-

ment also are stressors that can adversely affect human performance, including

physiological, cognitive, psychomotor, and emotional responses (Sanders & McCor-

mick, 1993).

For example, very high noise levels can be distracting as well as disrupting of

performance, and, if extremely high, painful. Loud impact noise can elicit a startle

response, and repeated impact noise can be very distracting and disruptive. Simi-

larly, temperature extremes and vibration also can be stressing. Low illumination can

degrade or distort perceptions of situations, objects, cues, and labels, and extremely

bright environments or glare can be blinding. Although these stressors can be dif-

ficult under otherwise nonstressful conditions, they can exacerbate conditions when

other stressors are present, such as discussed earlier. In investigating shooting cases

to determine whether or not they were unintentional or inadvertent, consideration

always must be given to determining if any unusual and pertinent environmental

factors were present that could have contributed to the incident.


FATIGUE

Fatigue, as used herein, refers to a condition brought about by a lack of sleep or chronic stress, which not only may result in feelings of tiredness and/or being worn out but in dysfunctional physiological and behavioral effects.

Often, threat situations occur at night when one may be very tired from the day’s activities, possibly exaggerated by chronic stress, or awakened well before having had an adequate amount of sleep. Before discussing the behavioral effects, let’s con-sider some basics of the physiology of sleep deprivation.

PHYSIOLOGICAL BASIS

The cerebral cortex is the brain structure where all mental activities such as plan-ning, analyzing, reasoning, and decision making occur. It is the large, folded, gray portion of the brain that covers over the other brain structures. In order for the cere-bral cortex to function properly, it depends on receiving stimulation from another portion of the brain, the Reticular Activating System (RAS). The RAS arouses the cerebral cortex so that it can pay attention and carry on its various mental activities, noted earlier. When a person is sleep deprived, RAS functioning becomes depressed. Consequently, the cerebral cortex does not receive the arousal it needs to pay atten-tion and effectively carry out its activities. In short, the functioning of the cerebral cortex is dulled (Kolasinski Morgan, 2005).

BEHAVIORAL EFFECTS

Not surprisingly, when the functioning of the cerebral cortex becomes dulled, it can result in errors in perception and judgment, slowed reactions, and poor deci-sion-making. For example, a police officer may still be able to fire a handgun but

may have decreased ability to quickly judge who or what is being fired at, and then,

whether or not to fire (Kolasinski Morgan, 2005). In addition, the officer’s aiming

accuracy may suffer. As Vila (2000) notes, police officer fatigue can cause poor

decision-making and eye-hand coordination problems. Similarly, a fatigued layper-

son holding a handgun and faced with a threatening situation may make errors of

judgment and/or inadvertently discharge the firearm. Although these dysfunctional

behavioral effects can, and do, happen with highly trained police officers, it stands to

reason that they are even more likely to happen to someone who lacks proper train-

ing in handgun safety while dealing with threat situations.

STARTLE

Imagine sitting in a theater watching a critical moment in a scary movie, with a

large bag of popcorn in your hand, and suddenly there is a very loud explosion in

the scene. Our guess is that you would involuntarily react by squeezing the popcorn

bag and jumping slightly out of your seat. The result would be popcorn all over

the place. Put simply, you were startled by the event and your body automatically

reacted accordingly.


The startle reaction is a whole-body, reflex-like response, most often to a loud auditory response, but also can be evoked by visual, vestibular, or somesthetic stim-uli (Bisdorff, Bronstein, & Gresty, 1994; Bisdorff et al., 1999; Hawk & Cook, 1997). The startle reaction evokes rapid involuntary contractions that begin with an eye blink and progress to include bending of the neck, trunk and shoulders, elbows, fin-

gers, and legs (Brown, 1995; Landis & Hunt, 1939). The reaction in the hands, which

occurs less than 200 ms (one-fifth of a second) after the stimulus (loud sound), is

for the person to make a fist. The magnitude of the startle reaction increases under

conditions of fear and arousal (Davis, 1984).

If a person is holding a handgun with his or her finger on the trigger, and some-

thing happens to startle him or her, that person is very likely to automatically respond

by squeezing his or her fist (hand and fingers), causing the handgun to fire. In our

case involving Betty and Bob, Betty, while urging Bob to tell her boyfriend that she

was not in the motel room, was holding her handgun facing upward with her elbow

bent. Her attention was focused on the door where her boyfriend was demanding

to be let in, rather than where her gun happened to be pointing or where her trig-

ger finger was placed (i.e., on the trigger rather than outside of the trigger guard

where it should have been). When Betty’s boyfriend suddenly banged on the door,

she understandably was startled and her handgun discharged. Very unfortunately,

her handgun happened to be pointed toward Bob, as her body was facing him, and

Bob was killed.

DIVIDED ATTENTION

In our example mentioned earlier, Betty was faced with more than one task requiring

her conscious attention: first, she was trying to convince Bob to say she was not in

the motel room with him (a task that she performed in response to the situation with-

out having to give it much thought); second, she was focused on the door where her

angry boyfriend was demanding to be let in; and third, she simultaneously needed

to consciously attend to where she was pointing her handgun and where her trigger

finger was placed.

Contrary to the popular saying, we humans actually can walk and chew gum at

the same time. We can because both tasks are so highly learned that they are auto-

matic and do not require our conscious attention. We humans also are capable of

doing two tasks at one time where one requires our conscious attention but the other

one is so highly learned that we can perform it automatically without thinking. For

example, highly experienced keyboard operators can transcribe correspondence or

numbers while thinking about something entirely different. By the same token, most

of us can drive a car while consciously thinking about other things. What we humans

cannot do effectively are two or more tasks simultaneously where both require our

conscious attention (Kahneman, 1975; Kerr, 1973; McLeod, 1977; Neisser & Beck-

lan, 1975; Wickens, 1984). As a result, at least one of the tasks will not get the atten-

tion it needs. In our real-life example, Betty attended to the door where her boyfriend

was demanding to get into the motel room (the source of her threat) rather than to

her handgun, which is very understandable given her circumstances and lack of any

formal handgun training.


Divided attention problems that can lead to an unintentional discharge of a hand-gun also can take place in the absence of threat or other acute stressors. Two of the authors investigated a case where a teenager was standing in front of a TV set watching a program and playing with a .22-caliber target pistol (Paradis & Hen-drick, 2001). He became involved in the TV program and, without looking, swung the pistol around to his right 90° to hand it to a friend who was sitting on a couch. In overcoming inertia to bring his arm and the pistol to a stop in front of his friend, he automatically squeezed the pistol to maintain good control of it (i.e., an involuntary muscle contraction of the hand and fingers). Unfortunately, his finger was on the trig-

ger, which required only 2.5 lbs of pull and 1/16th of an inch of movement to operate,

and the gun discharged, killing his friend. More is said about the issue of trigger

forces, including acceleration and overcoming inertia, in Chapters 4 and 10. Other

shooting cases involving divided attention can be found in Appendix A.

LOSS OF BALANCE

Some of the most common uses of involuntary muscle contractions are those elicited

by the nervous system to maintain various postures for performing movements and to

maintain balance (Horak & Macpherson, 1996). When a person loses balance, rapid

involuntary contractions are evoked in attempt to return the body to a position of equi-

librium. Included are involuntary contractions of the arm and hand muscles, including

the fingers. If the person is holding a handgun with his or her finger on the trigger, the

involuntary contractions can cause the trigger to depress and the gun to fire.

A second aspect of the postural contractions involves the neurological connec-

tions between limbs. If only one limb experiences the loss of balance, the invol-

untary contractions also will be evoked in the other limb, including the hand and

fingers (Coma, Galante, Grasso, Nardone, & Schieppati, 1996; Dietz, Horstmann &

Berger, 1989).

SYMPATHETIC CONTRACTIONS

Sympathetic contraction is a term coined by law enforcement officers for what also

is called mirror movement or contra lateral irradiation (Aranyl & Rosier, 2002;

Mayston, Harrison, & Stephens, 1999; Zijdewind & Kernell, 2001). When the mus-

cles in one limb are performing an intended forceful action, such as a police officer

restraining a suspect with one arm while holding a handgun in the other, an invol-

untary contraction will occur in the muscles in the other limb that, if the officer’s

finger is on the trigger, could cause the handgun to unintentionally fire. In a carefully

designed sympathetic contraction study, over 6% of the participating police officers

involuntarily placed force on the trigger finger exceeding the 11.4 pounds (double

action) required to fire the semiautomatic handgun used in the study, and others

placed pressure on the trigger just below that amount (Heim, Schmidtbleicher, &

Neibergall, 2006). The study did not involve a high-threat stress situation, which

likely would have resulted in a greater percentage of the subjects exceeding the 11.4

pounds and thereby involuntarily discharging the handgun.


INVOLUNTARY TRIGGER PULL

As already noted, various factors, such as startle, sympathetic contraction, loss of balance, and overcoming inertia in bringing a handgun to a stop, can result in invol-untary muscle contraction. Of particular concern here is involuntary contraction of the index finger when it is resting on the trigger of a handgun. Based on a number of

studies (Kearney & Chan, 1981; Moore, 1975; Shinohara, Keenan, & Enoka, 2003;

Zijdewind & Kernell, 2001), involuntary male trigger finger force can achieve an

average of 14 pounds (Heim et al., 2006); these authors note that, since this is an

average force, many persons reasonably can be expected to exceed it—particularly

in actual field situations because of the modulatory effects of stress on muscle con-

tractions (Delwaide & Toulouse, 1983; Noteboom, Barnholt, & Enoka, 2001; Wein-

berg & Hunt, 1976).

Enoka (2003) reviews a number of studies of involuntary muscle contractions

and explains how they can cause an inadvertent discharge of a firearm. In addition

to the causes of involuntary contractions of the hands and fingers, noted earlier,

Enoka particularly notes the role of cross-limb links: When a contraction occurs in

one limb, it evokes an involuntary contraction of the same muscles in the matching

limb. Sympathetic contraction, discussed earlier, is an example of this. Because of

these cross-limb links, strength training on one limb, such as an arm, will actually

result in a strengthening of the opposite limb, even though it has not undergone the

strength training.

ALCOHOL

It is well known, even to many laypersons, that alcohol impairs mental function-

ing. Moskowitz and Robinson (1987), based on a thorough review of the literature,

identified nine performance categories in which alcohol significantly impairs perfor-

mance. These are reaction time, tracking, concentrated attention, divided attention,

information processing, visual functions, perception, psychomotor skills, and driv-

ing performance. The blood alcohol content (BAC) at which statistically significant

effects were noticed varied between 0.03 and 0.1, depending on the specific perfor-

mance category. [Note: BAC is measured in grams of alcohol. Thus, a blood alcohol

content of 0.08 means that there is .08 grams of pure alcohol per 100 mL of blood.

The legal limit for driving in almost all states is a BAC of 0.08.]

The authors collectively have investigated numerous cases of unintentional

shootings in which the persons involved were under the influence of alcohol—invari-

ably in excess of a BAC of 0.1. Often, these were in stressful domestic situations or

other situations involving confrontations with others. One such example, as reported

by the shooter, is as follows (Paradis & Hendrick, 2001).

For a period of several months, an adult male cabinetmaker and his wife had

been under strain from being threatened by a neighbor in a rural Colorado town.

The neighbor apparently thought they had reported him as dealing in drugs to the

local police. As a result, the cabinetmaker, whom we will call John, carried a .357

Smith & Wesson pistol around with him in the house. John’s cabinet business had

been slow, so his wife, whom we will call June, was very worried about money. John


also probably was worried but seemed to be in denial about that. The day before the incident, John experienced symptoms of a heart attack. His wife took him to the hospital where he was thoroughly checked and later released (the symptoms most likely having been caused by chronic stress). The evening of the incident, while in the kitchen drinking beers together, June started to complain about how much his hospital bill was going to cost them because they did not have insurance. During the entire time they were drinking beer together, she expressed no concern or empathy for her husband and his recent heart attack scare. By this time they each had had approximately six cans of beer. John was near the sink. In his frustration over his wife’s complaining (and, most likely, her lack of empathy, although he did not men-tion that to the police), he picked up a dish and smashed it against the sink. A piece ricocheted off the sink and hit one of the children. June started screaming at John, so he picked the pistol up off of the counter and went outside to his workshop to cool down. At this point, John later told the police, he felt like a zombie and just wanted to get away from the turmoil. He further stated that he came back into the house, holding the pistol in his right hand, pointing up, adjacent to his right ear, with his finger on the trigger. As he started toward the hall to go to the bedroom, he stated

that June confronted him and said something like “You are not taking that gun to

bed with you” while, at the same time, suddenly grabbing his wrist and jerking it

toward her in an apparent attempt to grab the gun away from John. The gun went off

(an involuntary muscle contraction of the fingers, including the trigger finger) and

the bullet struck June in the head, killing her. All too often, shooting incidents occur

that involve the combination of alcohol and struggles over a handgun.

DRUGS

OVER-THE-COUNTER AND COMMON PRESCRIPTION DRUG EFFECTS

It is well known that several hundred over-the-counter and commonly prescribed

drugs affect human cognitive, emotional, and psychomotor functioning to various

degrees. Most common, as noted on many prescription bottles and over-the-counter

labels, is sleepiness, tiredness, and a warning not to drive. An example of a frequently

used medication is antihistamine. In some instances, persons also are warned not to

make critical decisions while under the drug’s influence. The labels on all medica-

tions should be read carefully in order to recognize their effects.

In light of the previously mentioned example, over-the-counter and legal pre-

scription drugs potentially can be a contributing factor in unintentional discharges

of firearms. In investigating such cases, it is necessary to check what medications the

person may have been taking and the reported effects of those medications on human

performance, including any known interaction effects of the medications being taken

by the handgun operator. Pharmacists usually can provide that information.

METHAMPHETAMINES

Although legally purchased medications can be a contributing factor in unintentional

discharges of firearms, a far more prevalent concern is with the influence of illegal

drugs. In particular, based on the authors’ investigations, methamphetamines are a


major problem. Methamphetamines also are known as shards, rock, pony, crystal,

glass ice, devil’s dandruff, and, in less pure form, crank or speed, or in crystalline rock form as dope (the term dope sometimes is used to refer to other drugs as well). It can be made from chemicals readily available in household products and over-the-counter medications, which makes methamphetamine appear unusually easy to make. So widespread is the use of methamphetamine that it has become a major focus of the U.S.’s war on drugs.

EFFECTS ON HUMAN FUNCTIONING

Methamphetamine is a highly addictive, very potent central nervous system stimu-lant that affects the brain by acting on mechanisms responsible for regulating a class of neurotransmitters known as the biogenic amines or monoamine neurotransmit-ters. The effects of the drug closely resemble the fight-or-flight response syndrome,

noted earlier in our discussion of stress, such as increased heart rate, blood pressure,

and physical strength, among other affects. It initially can cause feelings of euphoria,

which motivates people to take it. Unfortunately, it also results in paranoia, depres-

sion, long-term cognitive impairment due to neurotoxicity, psychosis, hallucinations,

and hostile, aggressive behavior (Beers & Berkow, 2003; Yudko, Hall, & McPher-

son, 2003).

METHAMPHETAMINE AND UNINTENTIONAL SHOOTINGS

From the previous description of the effects of methamphetamine on human physi-

ological, cognitive, and emotional functioning, it is not hard to see how persons

under the drug’s influence could inadvertently fire a handgun. What might not be as

obvious are cases where it is the person high on methamphetamine who gets shot!

We noted earlier some of the affects of the drug are increased physical strength,

paranoia, and hostile, aggressive behavior. Sometimes, the hostile, aggressive behav-

ior gets acted out against others who happen to be carrying a gun. We describe one

of our investigations to illustrate.

A 140-pound man, whom we shall call Joe, worked as a night guard and thus

carried a holstered handgun. He was married to a very large, 250-pound woman,

whom we shall call Janet, who was addicted to methamphetamine. They had been

having marital problems, and, on a prior occasion, Janet had beaten Joe while she

was high.

According to Joe’s testimony in this incident, Janet had left to go partying with

a female friend the night before and had come home in the morning and promptly

gone to bed. When she awoke around 11 a.m., Joe tried to talk with her again about

going to see a marriage counselor, as she had previously promised to do while not

high. Janet, still high on the meth (enough to have killed someone who was not a

long-term user, according to the toxicology report), became aggressive and grabbed

Joe’s gun out of his holster and threw Joe onto the ground, with him landing on top of

her. Janet started screaming, so Joe got off of her with his arms to see what was hurt-

ing her and repeatedly asked her what was wrong. He then saw that she had dropped

the gun by her left hip. Joe picked up the pistol, a Smith and Wesson semiautomatic,

and started to place it back in his holster. He raised his right elbow up behind him so


that his forearm and the pistol were pointing straight down toward the holster. Janet suddenly reached up, grabbed the underside of his wrist, and jerked it toward her (apparently trying to regain control of the gun), causing a classic startle response in Joe, resulting in the gun firing. Based on his testimony, Joe jerked back in surprise

and Janet continued to hold on, causing the gun to fire again. This second shot killed

her. He then lost his balance and fell forward, and, as the gun and his hand hit the

floor, the gun fired yet a third time (Paradis & Hendrick, 2001).

COST OF COMPLIANCE VERSUS PERCEIVED INJURY LIKELIHOOD AND SEVERITY

A well-known and well-researched area is the relation between the cost of compli-

ance and the perceived likelihood of injury and/or seriousness of injury as it affects

actual compliance with safety procedures. In general, if the cost in terms of effort

or discomfort for complying with a safety procedure is perceived as high, and the

perceived likelihood of having an accident or injury is low and/or that the injury

would not be severe, people are much less likely to comply. So, for example, if wear-

ing a piece of safety equipment is uncomfortable, difficult to put on, or makes doing

the job more difficult, persons are not likely to wear it. In contrast, if the perceived

likelihood of being moderately or seriously injured by not wearing the safety equip-

ment is high, persons may wear it anyway. Of course, the ideal is to design the piece

of safety equipment so that it is comfortable, easy to put on, and does not interfere

with task performance (i.e., low cost of compliance).

When looking at the design of a handgun and the required safety procedures

that should be followed, the design should be evaluated in terms of this cost-of-

compliance criterion. As is noted in detail in Chapter 4, there are aspects of hand-

gun design where this criterion is not met for specific firearms—particularly with

respect to procedures for knowing the handgun is not loaded or that a bullet is

not in the chamber—which have resulted in numerous inadvertent shootings and

related injuries and death. Perhaps the most common reason given for a firearm

inadvertently discharging is “I didn’t know the gun was loaded.” The authors have

experienced a number of such cases.

RECALL INTERFERENCE

A well-known phenomenon of human behavior is the fact that a person can do some-

thing and then interrupt that task to go do one or more other things, forgetting that

they had done, or been doing, something else. In cases where the person had done

something that affected the original task, then subsequently engaged in additional

activities, her or she may return to the previous task, forgetting that he or she had

altered the original task situation. For example, if a person has been practicing dry

firing with an unloaded gun, loads the gun, then engages in other activities before

returning to the dry fire practice task, he or she may fail to remember having loaded

the gun. As a result, he or she fires the gun, unintentionally shooting a bullet and

possibly hitting someone. Two cases involving recall interference are described in

Appendix A (Cases 5 & 6).


DESIGN-INDUCED HUMAN ERROR—MAJOR FACTORS

The cost of compliance criterion has direct implications for handgun design. When any aspect of the design that is related to safety has a relatively high cost of compli-ance, it indicates a need for redesign. Specific design features of various handguns

that are poorly designed ergonomically from a cost-of-compliance perspective are

pointed out in Chapter 4.

High cost of compliance is but one aspect of handgun design that can induce

human error. Others are as follows.

OVERSTRESSING HUMAN CAPABILITIES AND LIMITATIONS

Many capabilities and limitations of humans have been scientifically established, and

their implications for design are well known in the field of human factors and ergo-

nomics. Unfortunately, these capabilities and limitations often are not adequately

taken into account in the design of many products and systems, including handguns.

Included are the following.

ANTHROPOMETRICS: PHYSICAL STRENGTH

For any specific task requiring strength to perform, it is important to know the range

of physical strength capabilities of the population intended to use the product, such

as a handgun, and to design in strength requirements that can easily be met by that

population for effective intended use of the product. For handguns, this would include

such factors as the overall weight (strength required to hold it in firing position for a

given period of time), trigger pull force, and the force required to pull back the slide

on a given semiautomatic. In general, the ergonomic principle is to ensure that the

strength required to easily perform a given task should be met by the fifth-percentile

person in the intended user population. By fifth-percentile, we mean that only 5%

of the population has less strength in that particular area, such as finger pull. It is

important to note that a person who scores at the fifth-percentile level for one strength

application, such as finger pull, may score much higher or lower on other applications,

such as lifting an object from the floor or pulling a leaver. An underlying principle is

that if a fifth-percentile person can easily perform it, persons with less strength still

would be capable of doing it. Designing for still weaker persons usually significantly

increases costs and may create other disadvantages (e.g., being too easy to operate for

stronger persons, thus causing inadvertent operation by them), which is why the fifth-

percentile criterion most often is used with respect to strength requirements.

ANTHROPOMETRICS: PHYSICAL SIZE

In the early design stage of one of our older jet fighter aircraft, the second crew

member sat behind the pilot. In the case of an emergency, the crew members would

be strapped against their seats in preparation for ejection. For the second crew mem-

ber, the control for ejecting was on the wall in front of him. It turned out that anyone

with a reach distance less than that of a 95th-percentile person would not be able to

reach the ejection control. Here again is a situation where the fifth-percentile person


should have been used as the criterion, only this time for reach distance. In designing any product for human use, it is important to consider the range of any physical size characteristic that interacts with the product. With respect to handguns, hand size is an important consideration. More is said about this in Chapter 4.

PERCEPTION

All too often, product designs do not adequately take into account the nature and limitations of human perception, such as vision. For example, labels often do not provide adequate contrast for easy viewing, or the letter size, style, stroke width, and so forth is inadequate for the viewing task. Scientifically based design specifica-

tions, principles, and criteria exist, are well known to professional ergonomists, and

should be applied for easy viewing. In addition, it is important to remember that

color-coding, by itself, is inadequate because a significant portion of the population

is partially or completely color blind. Because handguns often must also be usable in

low illumination conditions, other coding methods, such as tactile coding, must also

be used in conjunction with color. Tactile coding refers to the ability to distinguish

things by virtue of their feel. For example, without looking, we can tell if our hand

is encountering a toggle switch or a round knob to turn on a light. More is said about

coding in conjunction with specific handgun features in Chapter 4.

Still another important consideration is to make sure that the design feature is

not ambiguous from a perception standpoint. For example, the location of labels

must be placed so that there is no ambiguity as to which control knob or lever, or to

which display, a given label is associated. Similarly, it should be clear and intuitive

as to how any given control is to be operated. Turn the knob clockwise to increase

volume, for example. All too often, this principle is violated.

When considering visual perception in design, it is not just those with 20/20

vision who must be taken into account, but also those who have degraded vision,

which ultimately includes most of the population.

In addition to visual perception, both kinesthetic (body part position and percep-

tion of a change in its position) and tactile (perception of what specifically you are

touching, as distinguished from touching some other part) perceptual capabilities

and limitations of humans also must be considered. For example, if the trigger on

a handgun will cause it to fire with a depression of 1/16th of an inch, it is almost

impossible for a person to stop the process in time to avoid firing, once beginning the

process. If the trigger also has an extremely low pull force, the person may well cause

the handgun to fire just by touching the trigger (i.e., by the time the person actually

senses he or she is touching the trigger, it may be too late). Although these issues are

important under normal, nonstressful conditions, they become even more critical to

consider for operation under high-stress, dim lighting, or moderately extreme tem-

perature conditions. In fact, it is to these less-than-ideal conditions that the handgun

intended for personal safety or home defense should be designed.

WORKLOAD

There are many facets to workload and how it is measured in the field of human fac-

tors and ergonomics. For our purposes here, what is important to consider is, for each


aspect of operating a given handgun, what else would the operator have to be doing at the same time? This includes not only physical tasks but also memory, perceptual discrimination, data processing, and decision-making tasks. Of particular impor-tance is the anticipated operator workload under acute stress and poor environmental conditions. A careful task analysis of a given handgun design can identify whether, under any foreseeable usage condition, a specific design feature of the handgun is too

complex, laborious, difficult, or untimely, and thus imposes an unrealistic workload

on the handgun operator.

RESPONSE TIME

Related to workload, how long it takes to perform some task in relation to how fast

it needs to be performed is another design consideration. Here again, a careful task

analysis for the anticipated use conditions can determine if task response time is

adequate or if redesign is required. One handgun example for design implementa-

tion would be comparison of the time required for candidate options to perform the

reloading function.

NEGATIVE TRANSFER OF TRAINING

Shortly after graduating from college, one of the authors, Hal Hendrick, went on

active duty as a second lieutenant, received training, and eventually was assigned to

Montauk Air Force Station as a radar controller. Around 3 a.m. one cold December

morning, an air defense fighter aircraft was under his control as it was descending to

land at Suffolk County Air Force Base. The plane was south of Long Island, flying

due north, coming in off of the Atlantic Ocean. An early morning fog was settled

over the airfield. Hal, sitting at his radarscope, gave directions to the pilot to get

his aircraft lined up with the runway, and told him to call as he descended through

10,000 feet. A few minutes later, the pilot radioed that he was passing though 10,000

feet, and that was the last Hal ever heard of him. The wreckage was discovered just

offshore, and at a location that indicated the pilot had actually been at 1,000 feet

when he radioed Hal.

It turned out that the problem was with the design of a new altimeter, recently

installed in the subject aircraft. The altimeter with which the pilot had flown until

recently was the classic, round dial, three-pointer type. It has a short pointer indi-

cating altitude in 10,000-feet increments, an intermediate-sized pointer indicating

1,000 feet increments, and a long pointer indicating 100-feet increments. In order

for a pilot to determine the plane’s altitude, the pilot has to integrate the information

from all three pointers. Because humans are poor at performing this kind of task

quickly and accurately, there was a concerted effort to come up with a better design.

The design of the new altimeter in the subject aircraft did away with one of the

pointers and had a direct readout at the bottom of the instrument for the 10,000-feet

increments, much like a car odometer, leaving only two pointers for the pilot to have

to interpret and integrate—a seemingly better design. However, under the stress of

landing his plane on an early winter morning with the runway completely fogged

in, the pilot regressed to his previously highly learned occupational stereotype and

interpreted the short pointer on his instrument as the 10,000-feet pointer, rather than


as the 1,000-feet pointer that it actually was. This is a classic example of what is known as negative transfer of training, and illustrates all of its key characteristics, as follows.

The operator has been very highly trained, both formally and/or through experience, on the use of a particular product design.The new design has features somewhat similar to the old design but requires a different interpretation or different means of operation.Although the operator can learn to use the new design, under stress, or when not paying conscious attention to it, the operator reverts to the previ-ously learned way, or what is known as the earlier occupational stereotype (i.e., stereotypical way of performing the function).

With respect to reverting to the old way when not paying conscious attention to it, most of us adults have had the experience of getting a new car and finding some

control that operates differently than on our old car, such as the windshield washer

control. Like the authors, you probably tried to operate it as you did in your old car

on occasions when you were not consciously thinking about it. Just imagine how

often you would walk into a room thinking about other things and push the light

switch up to turn on the lights, even if the switch design now required you to push

the switch down to turn it on. Although the previous examples are merely annoy-

ances, many others, like in the case of Hal’s fighter pilot, can be fatal. In fact, there

historically may have been more accidents and injuries from violating occupational

stereotypes than from any other single design cause. In any event, negative transfer

of training is major cause of design-induced human error.

When designing a new product to replace an old one, the primary way of avoid-

ing negative transfer of training is to make sure that it does not contain elements

highly similar to the old one.

A second way to avoid negative transfer of training is to standardize design

features and operational characteristics. For example, when the same general type

of product is designed and manufactured by different manufacturers, standardize

only those critical elements that, when switching from one manufacturer’s product

to another’s, could otherwise result in negative transfer of training having serious

safety implications. This is particularly relevant to the firearms industry, where there

is a lack of standardization on several critical components. These are addressed spe-

cifically in Chapter 4, including actual case examples.

When there is a lack of standardization among manufacturers’ products, it

becomes particularly important to make handgun operators aware of those differ-

ences through instructional materials and formal training.

LACK OF FORMAL HANDGUN SAFETY TRAINING

In almost all of the cases of unintentional discharges of firearms investigated by the

authors, the individual handling the firearm either had no formal handgun safety

training or the training was done a number of years ago and was of a highly question-

able quality. Given our experience, we are convinced that a lack of adequate training

•

•

•


is the major underlying factor in inadvertent handgun discharges by laypersons, espe-cially given the ergonomic problems with current handgun designs, alluded to earlier, and discussed in Chapter 4. In Chapter 9, we delve more deeply into the training issue and into what we believe constitutes an effective handgun safety training program and training system.

As a final note, one can go to almost any indoor firearm range in the country and

see the results of many of these human factors causes in the bullet impacts in the

walls, floors, and ceilings.

31

3 History of Firearms

INTRODUCTION

The purpose of this chapter is to provide you, the reader, with an understanding of the historical development of firearms and ammunition and thus set the stage for our

more detailed discussion of the components and mechanics of firearms, including

old ones still in use, covered in Chapter 4, and ammunition, covered in Chapter 5.

We wish to acknowledge the considerable assistance of historian David C. Willard

in preparing this chapter. The chapter provides an interesting and somewhat detailed

history of various types of firearms and ammunition, as well as their effects on

military tactics. For those only interested in the history of pistols and semiautomat-

ics, you may wish to skip to those sections, which appear in the latter portion of the

chapter.

GUNPOWDER AND EARLY GUNS

A basic knowledge of the development of gunpowder weapons and their methods of

employment can be useful in understanding the place of firearms in modern society.

The greatest impetus for firearms development came from their military uses. This

need set the standards to be met with regard to reliability, accuracy, power, and rate

of fire. It now is widely accepted that gunpowder was developed in China by the ninth

century AD as a mixture of charcoal, sulfur, and saltpeter (potassium nitrate) but with

an admixture of various other components that decreased its effectiveness. Gunpowder

was initially viewed as a drug, as well as being used for fireworks. The Chinese refined

the chemical formula over centuries and slowly weaponized it as well (Kelly, 2004).

The Chinese developed firelances, which were spears with attached bamboo

containers of powder designed to shoot flames at the enemy. Eventually, they found

that stuffing the mouth of the tube with projectiles (e.g., stones and bits of broken

porcelain) worked even better against the enemy, and the simple hand cannon was

born. Later, metal replaced the bamboo, allowing more powerful charges of powder.

Moreover, gunpowder was employed to make bombs that were launched by catapults

against besieged cities. The Chinese also invented rockets using gunpowder as pro-

pellant. They eventually even developed a primitive cannon. The Mongols quickly

adopted the technology when they conquered China (Kelly, 2004). By the mid-13th

century gunpowder was definitely known in Europe. Its formula was mentioned in

the writings of Roger Bacon in 1267. The first known record of its use is a reference

in 1280 to artillery employed at the siege of Seville in 1247, although this may refer

to catapult launched bombs rather than cannons. The first picture of a gun in Europe

is in a manuscript dating to 1327, which shows a vase-shaped gun called a pot de

fer mounted on a trestle and firing an arrow. Although the Europeans believed that

gunpowder was invented by a German monk named Berthold Schwartz, the man was


most likely a myth (our first hint being that schwartz is German for black, as in black

arts). The truth most likely is that gunpowder came to Europe in its developed form

from China. There are a couple of pieces of obvious evidence to support this prem-

ise. First, the proportions of saltpeter, charcoal, and sulfur were close to the modern

formula (75%, 15%, and 10%, respectively) from the outset in Europe, whereas it had

taken centuries of trial and error in China to reach it. Furthermore, guns of the pot

de fer type had been developed much earlier in China; one such gun was illustrated

in a carving from 1128 AD (O’Connell, 2002). It is known that the Mongols used

gunpowder against the Japanese, Hindus, and Muslims. The fact that it is known in

Europe shortly after the Mongols invasion of Europe is quite telling, but it could also

have come to Europe via an Islamic country or India. By the mid-14th century guns

were commonly known throughout western Europe.

The development of guns followed two evolutionary tracks consisting of small

arms and artillery. The early artillery pieces developed from the pot de fer into the

bombard and were used primarily for sieges. As time passed the development of artil-

lery bifurcated into indirect-fire and direct-fire types. The indirect-fire guns devel-

oped into mortars and howitzers, especially useful in sieges. The huge bombards had

a psychological effect. However, it was actually the medium-sized direct-fire pieces,

cannons such as the culverin with a much higher barrel-length to bore-size ratio,

which proved to be more effective against masonry. It was these guns that made

high, thin curtain walls as obsolete as the hand cannon made the armored knight,

thus leading to an entirely new fashion of fortification exemplified by the low-angled

bastion and known as the trace italienne.

The French were using this type of gun quite successfully by 1450, possibly

in conjunction with corned powder. The early culverin-type guns generally fired

shots about the size of a human hand and were often breech-loaded, making use of

a component shaped like a beer mug as a powder chamber held in place by a wedge.

This system helped increase the rate of fire and limited crew exposure to defensive

fire while reloading. The early shipboard guns, before the advent of wheeled car-

riages, tended to be of this pattern (Glete, 2000). Early guns were either cast bronze

or made from iron much like a wooden barrel, with iron staves welded together and

then reinforced by iron hoops that were shrunk onto the barrel. The fact that we still

call this component the barrel reflects this early development. The bronze guns were

safer, but they were more expensive and the technology did not yet exist to cast very

large guns.

The first European handheld firearm (hand cannon, hand gonne, or culverin à

main) had appeared in Europe by 1364 (Figure 3.1; DVD 3.1). This was simply a

tube of metal with one closed end, which was attached to a portion of a wooden pike

shaft. The powder was poured down the barrel, a projectile was pushed on top of the

powder charge followed by wadding, and the firearm was fired using a glowing coal

or smoldering match to ignite the gunpowder through a touchhole at the closed end of

the barrel. The area around the touchhole might be dished to hold a priming charge.

Initially the shaft was very long and the gun was supported by an upright pole, but

later it was shortened considerably and held under the upper arm for firing.

Primitive as they were, there are reports of hand cannons penetrating armor by

1425. They were better at that than either the longbow or the crossbow and had the

History of Firearms 33

additional advantages of being cheaper to produce than the crossbow (no spring steel required) and required less training to use than the longbow.

By the siege of Orléans in 1429 a French hand gunner is said to have been able to hit selected opponents, an early sniper if you will. Jan Žižka’s armies of Bohe-mian peasants, the Hussites, made extremely effective use of substantial numbers of this type of firearm, on a scale of roughly four crossbows to one gun, in the 1420s

(Turnbull, 2004).

The use of hand cannons in conjunction with numerous small artillery pieces

fired from the Hussite wagon forts formed the basis of a revolutionary new tactical

system that successfully fended off the crusaders who came to suppress their religious

beliefs. The field pieces they used were of two types, the smaller and more numerous

tarasnice and the larger houfnice or haufnitze. The former were essentially enlarged

hand cannons, of roughly 2-inch bore, initially fired from a stand, with wheeled

versions appearing around 1430. The houfnice, from which it is thought the modern

term howitzer is derived, had a short barrel and a bore diameter on the order of 8

inches to 12 inches and was mounted on a two-wheeled carriage.

Interestingly, even at this early stage the need for greater firepower was recog-

nized. There are examples of hand cannons with three and four barrels that could

be fired separately, allowing multiple shots before reloading. Similarly, in the area

of artillery during the first half of the 15th century, a field piece that consisted of

multiple small-bore tubes mounted on a cart was quite popular. This was known as

a ribaudequin, ribald, or organ gun. It had been invented by the Flemish to defend

breaches in walls. They introduced it onto the battlefield at Beverhoutsfeld in 1382.

The French king Charles VII hired two brothers to organize an effective artillery

train. This force of the latest artillery was instrumental in ending the Hundred Years’

War in favor of the French. In 1449 the French laid siege to Rouen, where 18 years

before Joan of Arc had been immolated. The city surrendered in only 3 days. In

Barrel

Muzzle

Touch Hole

Stock (handle)

FIGURE 3.1. The first European handheld firearm (“hand cannon,” “hand gonne,” or cul-

verin à main).


fact, during a 15-month period, some 70 strongholds were wrested from the English (O’Connell, 2002).

By 1470 the hand cannon had been fitted with something resembling a modern

rifle stock and a crude matchlock mechanism. These cumbersome weapons were

still in use as late as 1512.

Over the next 3 centuries metallurgy greatly improved in Europe and, beginning

with the matchlock system, a number of mechanical improvements evolved. These

are generally distinguished by the type of ignition system employed.

MATCHLOCK

The matchlock was commonly used in Europe from the mid-1400s until the early

1700s (Figure 3.2; DVD 3.2). The matchlock arquebus was one of the first and sim-

plest firing mechanisms to be developed that employed a flash pan. The flash pan

held a small amount of powder, which would prime the charge when ignited. A

match cord soaked in nitrates, so that it would smolder, was attached to a curved

piece of metal, known as a serpentine. When released, this dropped the glowing

match to the flash pan, igniting the priming charge. The immediate advantage of

this system was that it allowed the use of both hands to aim and fire the gun. There

were crude matchlocks from the early 15th century, the first known illustration of a

trigger-lever matchlock dating to 1411.

A more sophisticated mechanism was developed about 1440. This simple lever

was locked back until such time as a second lever was pressed. The second lever

later evolved into a trigger. The priming charge was next to a flash hole and, once

ignited, caused the main powder charge to ignite and launch the projectile from the

gun. [Note: The term trigger was originally tricker, apparently taken from the Dutch

trekker, from trekken, to pull, although given the unreliability of the early ignition

Trigger Guard

Action Cocked, Pan Closed Action Cocked, Pan Open

Trigger

SerpentineSlow match

Pan Pan Cover

Muzzle

Rear SightBarrel

FIGURE 3.2. Matchlock firing mechanism.


systems; it may well have had the meaning to trick the gun into firing in the minds

of many English gunners.]

The matchlock musket was the primary firearm used to conquer much of the

New World. Early versions were used by Cortes to conquer Mexico, by Pizarro to

conquer the Inca, and by English settlers to occupy the eastern seaboard of North

America. Without gunpowder technology, it is entirely possible that the Spanish

would have had no more success than did the Vikings 500 years earlier.

By 1525, at the battle of Pavia, the matchlock arquebus was in extensive use. In

spite of obvious limitations in damp weather and night operations, the matchlock

enjoyed a long service history—some 200 years in Europe. This was a much more

portable and ergonomically practical gun with an appearance more like modern fire-

arms. Shortly thereafter, in the 1530s, the heavy Spanish musket fired from a rest

came into use. It was less portable than the arquebus, but had greater range and much

improved ability to defeat armor because it could reliably penetrate any practical

armor at 100 yards and kill unarmored targets at 500 yards. Use of bigger guns was

made possible by butting them against the shoulder rather than against the chest or

holding them out at arm’s length (Guilmartin, 2003). Thanks to their smooth bores

these guns were inherently inaccurate and they had a slow rate of fire. To offset this,

the concept of volley fire was adopted.

Although the matchlock was obsolescent in Europe by the latter half of the 17th

century, it was used by both India and Japan until well into the 19th century.

WHEEL LOCK

The wheel lock design appeared c. 1510 (Figure 3.3; DVD 3.3). The mechanism

had a spring-driven wheel that was wound with a spanning tool similar to an old-

fashioned skate key. When the trigger was pulled, the pan-cover was retracted and a

serrated wheel spun against a piece of iron pyrite that created sparks and ignited the

powder charge. This type of lock is related to the mechanism of modern cigarette

lighters. It was an improvement over the matchlock in terms of safety as the need for

a lit cord in close proximity to gunpowder had been removed. It also was less vulner-

able to bad weather. But the wheel lock was complicated to produce and therefore

Trigger

Trigger Guard

Butt Cap

Winding Spanner

Wheel Spring

Stock

Barrel

Muzzle

Ramrod

Dogs Head(Hammer)

Iron PyritePan Cover

Pan

FIGURE 3.3. Wheel lock firing mechanism.


expensive. It was also relatively fragile, and, metallurgy being what it was at the time, the springs tended to be weak and prone to failure.

The real importance of the wheel lock stems from the fact that this type of lock work, when applied to pistols and carbines, brought cavalry into the gunpowder age. There had been matchlock pistols, but they were not conducive to use on horseback. The cavalry initially obtained a shortened musket (called a carbine or musketoon), or occasionally a blunderbuss. Later the pistol became popular (McPeak, 2006).

FLINTLOCK

This type of lock initially appeared in the form of the Snaphaunce c. 1550 (Fig-ure 3.4; DVD 3.4). The Spanish lock or miquelet, distinguished by an external main-spring, came into use by the 1580s. The true flintlock was developed in France c. 1612. The difference between the Snaphaunce and the other two systems is that, in the former, the frizzen and the pan cover are two separate pieces, although in the later types they are combined. The system used a hammer (known at the time as the cock due to its appearance being reminiscent of a rooster’s head) that held a piece of flint in a vise-like system. The hammer would be drawn back until held in place by a sear. When the trigger was pulled the hammer would release under spring pressure, striking the flint against a piece of steel called the frizzen. This created a shower of sparks into the gunpowder in the flash pan, thereby igniting the priming charge.

Probably the most famous flintlock of them all, the British Brown Bess musket, had partially reequipped the English army in time for the Battle of the Boyne in 1690 (Niderost, 2006). The invention of the bayonet allowed the infantry to dispense with pikemen. The plug bayonet appeared in 1640 and consisted of a dagger with

Cock(Hammer)

Stock(Grip)

Frizzen

FrizzenSpring

Barrel

Muzzle

Ramrod

Pan

Flint

Trigger GuardTrigger

Butt Cap

FIGURE 3.4 Flintlock firing mechanism.


a bulge in the grip to wedge it firmly into the muzzle. The obvious disadvantage,

that the gun could not be fired while the bayonet was fixed, was brought forcefully

home to the British at Killicrankie in 1689 (Newark, 2005). The socket bayonet had

already begun to appear, and some of William’s elite units were equipped with it

at the Battle of the Boyne. It was adopted into general British service in 1710. The

weapons were still smoothbore muzzle-loaders though. This meant that they were

inaccurate beyond 70–80 yards and still had a slow rate of fire, a trained man theo-

retically being able to make three shots per minute. Therefore the tactics of the day

still involved blocks of men employing volley fire. The Brown Bess was the primary

infantry weapon of the British Army during Marlborough’s wars, the American

Revolutionary War, and the Napoleonic Wars, although the flintlock Baker Rifle was

adopted for limited use in 1800.

CAP LOCK

In the first three types of systems, weather could interfere with the operation of the

firearm. Although each was an improvement over its predecessor, they were typi-

cally slow and cumbersome. The percussion principle, invented in 1807, was stimu-

lated by a sporting rather than a military incentive. A Scottish clergyman, frustrated

in his duck hunting by the fact that the birds were able to move quickly enough

during the delay between the audible click when the cock of his flintlock fell and

the actual ignition of the powder charge, designed a new system. The heart of the

system was a small brass or copper cup-shaped cap containing fulminate of mercury,

a shock/pressure sensitive explosive in a stable form. The cap was slipped on to the

top of a small tube-like protrusion referred to as a nipple, which replaced the earlier

flash pans. When the trigger was pulled the hammer would hit the cup, putting sharp

pressure on the explosive priming compound inside. The priming compound would

explode, sending the burning material into the gunpowder main charge through a

flash hole and igniting it. This yielded a much faster ignition time, and the new

system began to replace the flintlock during the first half of the 19th century (Fig-

ure 3.5; DVD 3.5). This system was in widespread use by 1826 and was the primary

type of lock used during the American Civil War. The cap lock was the last common

ignition system developed prior to the introduction of cartridge systems and was

used with some early cartridge guns such as the early versions of the Sharps rifle.

The Sharps rifle used paper cartridges in conjunction with a separate percussion cap

for ignition. In modern cartridges the primer is incorporated into the cartridge. The

term sharpshooter is derived from the Sharps rifle.

There were many variations of these mechanisms and other designs as well. Many

are still being produced for reenactors, collectors, and antique firearms enthusiasts.

AMMUNITION

Gunpowder was initially a mixture of saltpeter, sulfur, and charcoal that had been

pulverized. The resulting meal powder was not very powerful and tended to separate

over time when being transported. A major advance was the development of corned

powder c. 1420 (Black, 2002). Corned powder was essentially black powder that had


been moistened (usually with human urine) and worked into a dough, then ground and sieved to a specific size after it had dried. It was more reliable and more power-

ful when used in culverins and muskets. During the early centuries of gunpowder

use, the degree of quality control left a lot to be desired. Besides the inconsistency of

the quality of the powder, it was perishable and vulnerable to dampness (Murphey,

1999). Projectiles from early guns could be bits of metal, stone, or porcelain, or, in

some of the earliest types, an arrow. In time, the round ball came into favor. Projec-

tiles for the early bombards were hand-carved stone. The development of cast iron

round shot married to cast bronze culverins meant the end of tall masonry curtain-

wall fortifications. It was this combination that King Charles VII of France used

to end the Hundred Years’ War and that King Charles VIII used to take numerous

fortified positions in Italy in record time at the end of the century. Fortifications that

would have held out for months against older guns and ammunition fell in a matter

of days or even hours.

Although there had been early examples of breech-loading cannon and muskets,

in general, these were not successful because the technology of the time did not allow

for effective obturation (sealing) of the breech. In the area of small arms, with few

exceptions (such as the Ferguson rifle), guns were muzzleloaders for several hundred

years. This meant the soldier carried a flask of powder and a container of bullets.

Although paper cartridges were in use by the mid-1500s (Brzezinski, 1993), many

musketeers and dragoons (mounted infantry) in the early 17th century sported ban-

doliers from which were suspended premeasured powder charges in a dozen wooden

bottles (nicknamed the 12 apostles) and kept a couple of bullets in their mouths

ready for loading. The early paper cartridges were just a premeasured powder charge

(Kelly, 2004), but later the bullet was incorporated as well. With these cartridges the

shooter just needed to tear off the end of the paper with his teeth and pour the pow-

Stock(Grip)

Action Cocked

Hammer

Trigger Guard

Trigger

Lock PlateRamrod

Muzzle

Front SightBarrelRear SightNipple

FIGURE 3.5. Cap lock firing mechanism.


der down the muzzle before ramming the ball down after it. Matchlock and flintlock shooters might use a portion of the powder as a priming charge. Although weapons using cartridges that included the primer did not really begin to see widespread use until mid-century, a Swiss artillery officer named Pauly designed the first centerfire

cartridge in 1812. It had a cardboard body and a brass head that effectively obturated

the breech. Unfortunately this was not a commercial success.

The pinfire cartridge system was invented in 1823 by Casimir Lefaucheux,

although it was not patented until 1835. These metallic cartridges had a pin pro-

truding from the top of the body of the cartridge at the back, near the head of the

cartridge. When struck by the hammer this pin was driven into the primer, which

was located inside the cartridge case. The double-barrel break-open shotgun, used

commonly today, was first invented to use pinfire shotgun shells in 1835. This design

was the first practical metallic cartridge system for shotguns, rifles, and handguns.

It saw extensive use in revolvers during the American Civil War, although it was

overshadowed in sheer numbers by Colt and Remington percussion models. Pinfire

revolvers were also widely used in European armed forces until the advent of the

center fire ignition system.

Contemporaneous with the pinfire, the single-shot needlegun rifle appeared in

1840. It used a paper cartridge with a primer on the bottom of the bullet that would

be hit by a very long firing pin, the needle, which drove all the way through the

powder charge to reach it. The system was adopted by Prussia and was ultimately

the standard rifle of the Prussian army during the Franco-Prussian War in 1870, by

which time it was obsolescent and outclassed by the newer French Chassepot rifle,

introduced in 1866.

The Crimean War of 1854–1856 was the last war in which all combatants

employed front-loading guns. In 1854 Americans Horace Smith and Daniel Wes-

son manufactured the first practical repeating pistol using a cartridge, the Volcanic,

which would also form the basis of later Winchester lever-action rifles. The Volcanic

was a failure because the cartridge was too weak. In 1859, Smith & Wesson pro-

duced the first rimfire cartridge. The period of the American War Between the States

was a remarkably innovative period in the area of firearms. Among the advances it

saw in the area of ammunition was the widespread use of conoid bullets, such as the

Minié ball. This type of bullet had much better exterior ballistic performance from

rifled barrels than the round ball that they soon began to replace.

Metallic cartridges were widely introduced from 1863–1864. Shortly after the

war, Colonel Hiram Berdan developed the first center fire cartridge in 1866. The Ber-

dan priming system, in which the anvil was part of the cartridge case, soon became

the world standard system outside the United States. The United States adopted

instead the system invented by Edward Boxer in 1867, in which the anvil was part of

the primer. The salient difference is that spent Boxer cartridge cases can be reloaded

easily for reuse. Ironically, Berdan was an American, whereas Boxer was British.

These priming systems are further explained and depicted in Chapter 5.

In 1884 smokeless powder was invented and soon began to replace the black

powder that had been used in firearms since their inception. The French introduced

an 8mm cartridge for their new Lebel rifle in 1886. Because this cartridge used the

new smokeless powder, the shooter did not tend to give away his position and obscure


his vision, as had previously been the norm. The bullet was much smaller than the 11mm black powder round that preceded it, so the soldier could carry more ammuni-tion. The bullet was covered with a copper jacket, which reduced lead fouling of the bore. The cartridge substantially outranged other military rifles of the time.

In recent decades, pistol ammunition has been transformed by the introduction of hollow-point and frangible bullets for defensive use. These are used by both police officers and citizens because they are less likely to overpenetrate and are more likely

to stop an assailant quickly. This is vital in nonmilitary defensive situations. The

military is limited to full metal jacket bullets due to treaty restrictions. These vari-

ous types of bullets are further described and depicted in Chapter 5.

RIFLES/CARBINES

Rifling had been invented as early as 1498 as an attempt to allow more shots to be

fired before cleaning the fouling out of the bore of a musket (the earliest examples

had no twist to the grooves). Rifled arms existed by 1540, and reportedly were occa-

sionally used for sniping. But because they were tedious to load, they were little used

except for hunting. Rifles were used extensively by American colonial militias, but

while they had greater range and accuracy than the smoothbore, they were slower to

load and could not accept a bayonet. It was not until the rapid advances in technology

of the mid-19th century that their use for military purposes became more practical.

The needlegun of 1840 was a single-shot weapon and was the progenitor of all

later turnbolt rifles. It was the first practical system adopted by a military for a rifle

that employed a self-contained cartridge, although obturation problems limited its

range. In 1854, Smith & Wesson patented a lever-action magazine pistol (Jinks,

1977) that was the basis for the lever-action Henry rifle that appeared in 1860. The

Henry saw some usage in the Civil War, although it was not officially adopted by

the North. It was the starting point for the later Winchester lever guns. Also in 1860

the Spencer repeating rifle was patented and eventually saw considerable service

with Northern forces. It was the first breech-loaded infantry rifle with a removable

magazine, a tube inserted into the butt of the gun. The Spencer allowed a soldier to

carry multiple preloaded seven-shot magazines. Both the Spencer and the Henry

fired rimfire cartridges. Centerfire cartridges soon began to replace them in newer

designs after the Berdan and Boxer centerfire systems became available.

Lee patented the detachable box magazine in 1879 with the Remington-Lee. The

French Lebel appeared in 1886 with its revolutionary smokeless powder cartridges.

The rest of the European nations scrambled to produce a viable counter to the Lebel.

The Lebel employed a tubular magazine under the barrel that held eight rounds and

was slow to reload. The rifle that Mauser built in response in 1889 used an integral

box magazine that could be loaded much more quickly by means of five-round strip-

per clips. The British Lee-Metford appeared in 1889 as well and used a detachable

staggered-row box magazine. It would evolve into the Short Magazine Lee-Enfield

and equip British and Commonwealth troops through two world wars and beyond.

These rifles and others like them equipped the soldiers of the Great War, and most

of the armies of World War II as well.


In the interwar period, the Americans adopted two signature long-arms, the M-1 Garand and the M-1 Carbine. The Garand, which was adopted in 1937, was the first

widely issued military semiautomatic rifle. It fired the powerful .30–06 cartridge

and employed eight-round en bloc clips. This was an odd choice because the en bloc

system had been developed as early as 1885 by Mannlicher and was known to have

the disadvantage that the gun could not be topped off after firing a few rounds. The

Carbine was intended to give personnel whose duties precluded the carrying of a

full-sized rifle a weapon that was lighter in weight than the service rifle and yet had

greater range and accuracy than a pistol. Whereas previous carbines had generally

been scaled-down muskets or rifles to make them more manageable on horseback,

they typically fired standard rifle ammunition. The M-1 Carbine fired a super pistol

cartridge. Since the inception of the M-1 Carbine, the term carbine has been some-

what more loosely defined in modern parlance. Many carbines are now chambered

for pistol caliber cartridges, although others are the more traditional shortened ver-

sion of a full-caliber rifle.

During World War II a radically different type of military long-arm was intro-

duced in the form of the German Sturmgewehr 44. The word Sturmgewehr is liter-

ally translated as assault rifle, and its characteristics define the type. The StG 44

was a select-fire (i.e., semi- or full-auto) weapon that employed a large-capacity (30

round) detachable staggered-row box magazine and fired an intermediate cartridge.

This cartridge was a shortened version of the standard German 7.92 mm rifle car-

tridge. Note that in recent years the term assault weapon has come into widespread

use. This has no standard technical definition, as it is a legal term of art that must be

defined in any legislation that employs it.

In 1945 Simonov invented the SKS rifle, which employed a similar intermedi-

ate cartridge, the 7.62x39 mm. This rifle was adopted by the Soviets and issued in

1946. Being semiautomatic, it was the tactical equivalent of the American Garand.

It was soon succeeded by the AK-47 assault rifle in Soviet service, and this gun was

produced in prodigious numbers and distributed to clients and allies of the Soviets

worldwide. In addition to the millions of original AK-47s still extant, its descendants

and spin-offs such as the Valmet and Galil are in widespread service today.

Western nations began the postwar era with the introduction of semiautomatic

rifles using detachable box magazines. Typically these were chambered in the NATO

standard 7.62x51 mm rifle cartridge. The United States adopted the M-14, which

directly descended from the M-1 Garand. Many countries around the world, includ-

ing Britain and the Commonwealth, adopted the Belgian FN FAL. Others adopted

the German HK 91, which had been developed from the Spanish CETME design.

In the midst of its Vietnam experience, the United States adopted the M-16

assault rifle. The M-16 uses a .223-caliber bullet in bottlenecked case. The small

bullet is thus driven to very high velocity. In recent years NATO has adopted this

as a standard rifle caliber, and later AK variants, such as the AK-74, use a simi-

lar cartridge. Although the United States and Canada still use updated variants

of the M-16, other countries have designed new rifles to fire the same cartridge.

These include the Belgian FNC, the Italian AR70, the Swiss Sig 550 Series, and the

Israeli Galil. In more recent years there has been a trend toward bullpup designs

for military use, which employ the same cartridge. A bullpup has the action behind


the trigger, making for a short overall length while retaining a full-length barrel. Among these are the Austrian AUG, the French FAMAS, the British SA80, and the new Israeli Tavor.

A number of modern guns, such as the FN P90, have been designed in recent years to fulfill military requirements for a Personal Defense Weapon (PDW). They

are linear descendants of the M-1 Carbine.

REVOLVERS

The idea of a revolver, as with many other modern ideas, has a surprisingly long

history. There were matchlock revolving muskets, but they had obturation problems.

The Collier flintlock designs of the early 18th century actually worked reasonably

well. Early in the 19th century the percussion pepperbox design was quite popular.

Although there were many different styles of firearms incorporating new fea-

tures, the Colt revolvers were a milestone in firearm development. Samuel Colt

(1814–1862) developed and patented a handgun that had a revolving cylinder in 1836.

This was the first revolver that rotated and locked the cylinder in the firing position

by cocking the hammer, making multiple shots fast and reliable. Colt’s Model 1851

and Model 1860 percussion revolvers were the primary sidearms used by the Union

forces during the Civil War. The Model 1851 also was adopted by the British over

the double-action-only Adams design. The British felt that the six-shot, single-action

Colt was more accurate because the Adams could not be cocked and fired. Adams

rectified this with the introduction of the double-action Beaumont-Adams that had

the capability of being thumb-cocked like a single-action gun. The five-shot Adams

did fire a larger caliber bullet; both .49-caliber and .44-caliber versions having been

offered. With this introduction, one of the classic handgun controversies, smaller

caliber and larger capacity versus larger caliber and lower capacity, was born, epito-

mized by a couple of anecdotes.

During the Crimean War (1853–1856) a British officer wrote to Adams to tell

him how he had used his nearly .49-caliber Adams to stop four Russians in quick

succession as they were trying to bayonet him. Later, during the Sepoy Mutiny in

India (1857–1859), a hapless British officer emptied his Model 1851 Navy Colt into

an attacker only to have the man split his skull from top to teeth with his sword

before he himself died (Hogg, 1979, p. 47). Reportedly, several of the small .36-cali-

ber high-velocity bullets had passed completely through the attacker. (In fairness it

should be noted that one of the most famous and deadly pistoleers of the American

West, Wild Bill Hickock, carried a pair of Navy Colts for most of his career.) Fifty

years later Americans would tell similar stories comparing the performance of the

.38 Long Colt to that of the .45 Colt in the Philippines Insurrection.

In 1857 the first revolver with a bored-through cylinder for use with unitary

metallic cartridges, a tip-up design (described and illustrated in Chapter 4), was mar-

keted as the Smith & Wesson Model 1 in caliber .22 Short and was popular with offi-

cers during the Civil War. In 1859 the first European centerfire revolver, the Perrin &

Delmas, was patented. The first swing-out cylinder double-action revolver to appear

was the Iver Johnson Model 1879. This type did not become popular though until

the U.S. military adopted the first Colt swing-out cylinder revolver, the Model 1889.


Smith & Wesson, which is now famous for this type of handgun, did not introduce its first swing-out cylinder revolver until 1896. Swing-out revolvers are described and

illustrated in Chapter 4.

Despite having largely been superseded by semiauto pistols from the late 1980s

in civilian and police use, revolvers still have an extensive following. Modern revolv-

ers are produced by a number of companies including Colt, S&W, Ruger, and Tau-

rus. The revolver is generally felt to be more reliable than the semiauto, but it is

handicapped by its relatively low ammunition capacity and the fact that it is slower to

reload. In recent years the introduction of seven- and eight-shot revolvers along with

speedloaders or the use of moon clips has helped offset that disadvantage somewhat.

Note that these latter modern inventions are really not that new. Smith & Wesson

patented a moon-clip device for a break-top revolver in 1886. The British had devel-

oped a type of speedloader that was used with their Webley-Fosberry semiautomatic

revolver prior to World War I. In 1916 Smith & Wesson invented the half-moon clip

to allow the use of the rimless .45 ACP cartridge in revolvers issued to troops in

World War I (Jinks, 1977, p. 204). Speed loaders and moon clips are described and

illustrated in Chapter 4.

SEMIAUTOMATICS

In 1893 the first successful self-loading pistol appeared, developed by Hugo Bor-

chardt after first creating the bottlenecked rimless cartridge necessary to make

the gun work. The design borrowed the toggle action and reciprocating bolt of the

Maxim machine gun of 1884 and used a detachable box magazine. Some 3,000 were

produced, but the gun was unwieldy and fragile.

Mauser entered the market in 1896 with the Mauser Military, commonly referred

to as the Broomhandle. This was another single-action gun with a reciprocating bolt,

but it had a higher capacity 10-round nondetachable magazine in front of the trigger

guard loaded by means of stripper clips. The young Winston Churchill carried one

of these pistols at Omdurman.

John Moses Browning’s first semiauto, using the now common arrangement of a

slide, appeared in 1900 manufactured by the Belgian firm FN. Gavrilo Princip used

a Browning Model 1900 to assassinate the Archduke Franz Ferdinand and his wife

in 1914, the event that sparked World War I.

In response to the challenge from Mauser, the producer of the Borchardt, DWM,

set Georg Luger to the task of cleaning up the Borchardt design, and the result was

the Parabellum pistol. This pistol is commonly referred to as the Luger, and it was

adopted in Switzerland in 1900. This gun served alongside the Mauser Military in

German service during World War I.

A Browning design won a competition in 1907 and was adopted in 1911 by the

U.S. military, with which it served until 1985 as the Model 1911-A1. Unlike its .30-

and .36-caliber contemporaries, this design employed a larger caliber cartridge, the

.45 ACP.

In 1929 Walther introduced the Model PP, the first successful double-action

semiautomatic pistol. In its PPK form, made famous by the James Bond films, it

is still in production today. Walther followed this success with the P-38 that was


adopted by the German military in 1939 to replace the Luger. This was the first

double-action service pistol.

The Browning Hi Power was introduced in 1935. This was the first successful

semiautomatic handgun to use a detachable staggered-row high-capacity box maga-

zine. It held 13 rounds of 9 mm Luger.

In 1980 the prototype of the Glock 17 won the competition for a new Austrian

service pistol. It was the first semiautomatic pistol to use a polymer frame. In 1985

the U.S. Armed Forces adopted the 9 mm double-action Beretta 92 to replace the

M1911-A1 and finally conform to NATO standardization agreements. In a relatively

short time, almost a thousand American police agencies had adopted the Beretta 92

as well. The Glock soon came on the scene and eventually would equip the major-

ity of American police agencies. As this shift by American police from their tradi-

tional use of revolvers to high-capacity 9 mm pistols occurred, the gun-buying public

turned more and more to their use as well.

POCKET PISTOLS

Truly concealable self-defense handguns became possible with the invention of the

flintlock. Small box lock flintlocks were quite popular as gentleman’s or muff pistols

in the 18th century. These could be kept at hand in a waistcoat pocket or a lady’s

hand warmer. Slightly larger versions were called overcoat pistols. These were sin-

gle-shot pieces for the most part, some with turn-off barrels that unscrewed to load

from the breech. The box lock referred to a pistol in which the cock mechanism was

centered in the gun rather than on the side. They were intended for very close range

use, as the cock made them virtually impossible to aim.

The first percussion versions appeared in the 1830s. A small large-bore gun

introduced by a man named Deringer was so popular that derringer became a com-

mon term for pocket pistols. Abraham Lincoln was assassinated with such a gun.

When cartridge technology became available in the 1860s, multibarrel pocket

pistols became popular. A quite common version was a .41 Rimfire over-and-under

model. Four-barreled .22 Rimfire guns were popular ladies’ guns.

Later in the century, small break-top revolvers appeared to compete with the

smaller guns. These were chambered in rather anemic calibers such as the .32 and

the .38 S&W. These were popular well into the 20th century, when they were sup-

planted by small solid-frame swing-out cylinder revolvers such as the Smith & Wes-

son J-frame guns, which could accommodate the .38 Special cartridge.

Small pocket semiautomatics also became popular from the beginning of the

20th century. Some of Browning’s earliest guns were .25 ACP, .32 ACP, and .380

ACP pocket guns. The Walther PPK has been available since the 1930s. Toward the

end of the century much more powerful pocket autos became available. In part, this

was due to the Clinton assault weapon ban that limited all handguns to a maximum

10-round magazine. This, coupled with an increasing number of states allowing con-

cealed carry, provided the impetus to downsize Glocks and other double-stack 9 mm

guns. The result was a number of pistols with a capacity of 11 rounds of 9 mm Luger

only slightly larger than the envelope of a single-stack .380, like the PPK.


DESCRIPTIONS OF DVD PHOTOS

DVD # Description

3.1 The first European hand-held firearm (“hand cannon,” “hand

gonne,” or culverin à main)

3.2 Matchlock firing mechanism

3.3 Wheel lock firing mechanism

3.4 Flintlock firing mechanism

3.5 Cap lock firing mechanism

47

4 Handgun Components

and Mechanics

PREFACE

The purpose of this chapter is to acquaint the reader with the various components of revolver and semiautomatic handguns and their mechanics of operation, includ-ing variations in their design and mechanics. Particular emphasis is given to those aspects of handgun design that can induce human error. In describing the design and mechanics of handguns, human factors/ergonomics safety concerns are highlighted in bold type. In addition, major human factors/ergonomics safety design issues are summarized at the end of the chapter.

INTRODUCTION

Both the power and size of handguns have increased over the years. There are many configurations. As new materials and methods have been developed, manufacturing

has gone from crudely made metals to space age plastics and metals in the quest

for greater rates of fire, improved accuracy at longer ranges, and projectiles that are

more powerful. Old designs once long forgotten are being brought back to life in

today’s modern firearms. Wheneverthereappearstobeageneralrule,somebody

somewheredevelopsanewdesign thatgoesagainst thecommonrule.Some-

times,theresultfortheoperatorinusinganewhandguncanbeconfusionand

unintentionaldischargeof thefirearm (e.g., see negative transfer of training in

Chapter 2).

In the United States, the term handgun means a firearm designed to be fired with

one hand. The term pistol can describe a handgun that does not have a cylinder but

may have a multitude of barrels. Handguns also can be broken down to other sub-

groups, such as semiautomatics and revolvers (which have cylinders that revolve). In

many countries outside of the United States, the term pistol refers to all handguns.

When discussing firearms parts and mechanics, one can describe the common gen-

eral characteristics but must be aware that some designs may not be what they seem.

Terms such as common, usually, generally, and so forth, are used to make the reader

aware that there often are exceptions to the rule or designs that do not fit general expec-

tations. With this word of caution, we look at some of the common parts and designs.

It is important to realize that there have been many different firearms developed

through the years as well as alterations to original designs. Whetherduetopatent

rightsorotherfactors,manypartsmaylooksimilarbutvaryagreatdealin

function. Every firearm should be researched not only to the different subclasses

into which it may fall but individually to insure that the parts function as designed.


Often the Internet provides ready access to manufacturer’s manuals, as well as to sites devoted to specific firearm models and the potential problems that have been

noted. It is not possible to cover every variation one might encounter. This book is

targeted to common handgun-type firearms using cartridges with smokeless gun-

powder charges, but may be applicable to other similar types of handguns, such as

air pistols and black powder firearms and, to some degree, long arms. Handguns

have some of the same general parts as other firearms, and the parts have similar

functions, such as the barrel, frame, and action.

LOCK, STOCK, AND BARREL

In the days before modern manufacturing, the future gun owner could go to a wood

worker to make a stock, a locksmith to make the trigger mechanism, and a blacksmith

to make the barrel, or could commission someone to make it lock, stock, and barrel,

meaning complete. Today, there are still custom manufacturers in the industry that

can upgrade, build parts, or build a complete firearm. All firearms have these three

basic features, now known as barrel(s), frame, and action (Figure 4.1; DVD 4.l).

The barrel is the metal tube that the projectile passes through, providing direc-

tion for the projectile. The barrel’s inside diameter is referred to as the bore diam-

eter. The action consists of all the moving parts of the firearm that allow it to load,

fire, and unload. The frame is the part of the firearm that holds all the other parts

together, allowing them to function correctly.

NOMENCLATURE

A handgun is a firearm that typically is designed to be held with one hand. Further

subclasses can be broken down as single shot–single barrel, single shot–multiple

barrels, revolvers, and semiautomatics.

Frame consists of the nonmovingparts that hold the moving parts

and the barrel in place

Action includes all the movingparts inside of the frame including

the mainspring that is usually located in the frame under the grip

Barrel is the tube that theprojectile travels through

FIGURE 4.1. Frame, action and barrel.

Handgun Components and Mechanics 49

The action of a firearm is a name that describes the system of operation. Some

relatively common types are shown later with main parts nomenclature. Each suc-

cessive type lists pertinent main parts nomenclature not previously defined.

When reference is made to the front of the firearm, this means the muzzle end

of the firearm. When referring to the rear, this is where the grips are. The right and

left sides are with the firearm pointing away (muzzle forward), perpendicular to a

person’s body (Figure 4.2; DVD 4.2).

SINGLE SHOT–SINGLE BARREL

Single-shot, single-barrel handguns are direct descendants of the black powder type

firearms (see Chapter 3). They have a release that allows the barrels to tip up/down

or swing out to load and unload a single cartridge into the chamber (Figure 4.3;

DVD 4.3). This style of firearm only allows for one shot to be fired, and the process

of removing (extracting and ejecting) the fired cartridge case and loading a new

cartridge must be completed in order fire the next shot. Many parts exist today in the

same configuration and use as in the earliest single-shot handguns.

BARREL NOMENCLATURE

Barrel. A tube through which the projectile travels. Typically, the barrel has

lands and grooves (DVD 4.4).

Muzzle Front

Left Right

Back

FIGURE 4.2. Depiction of the muzzle, left, and right directions for a handgun.


Lands and Grooves. High points (lands) and low points (grooves) cut into the inside of the barrel in a twisting direction (DVD 4.5). For every land there is a groove. A firearm may have two or more lands and grooves. This allows

the projectile to have a gyroscopic spin in flight, which stabilizes it during

flight and allows for greater accuracy.

Muzzle. The end of the barrel where the projectile exits (DVD 4.6).

Crown. The physical portion of the barrel surrounding the opening (DVD 4.7).

Crowns can be different in shape but are uniform around the barrel in a

given style. Damage to the crown can cause gasses to be released nonuni-

formly and can affect accuracy of the projectile.

Chamber. The opening at the loading end of the barrel that holds and supports

the cartridge in single-shot and semiautomatic firearms (DVD 4.8). Revolv-

ers and multiple-barrel firearms have multiple chambers. Each chamber can

hold one cartridge.

Front Sight. The forward aiming point on the front of the barrel (DVD 4.9).

Rear Sight. Rear aiming point on the rear end of the barrel or top of the frame

(receiver) at the rear end of the firearm (DVD 4.10).

ACTION NOMENCLATURE

Extractor/Ejector. On some types of firearms, such as a revolver with a swing-

out cylinder, these terms can be used interchangeably if the part both

extracts the cartridge or casing from the chamber and aids in ejecting the

cartridge out of the firearm (DVD 4.11).

Hammer. A part of the firearm firing mechanism that provides force to ignite

the primer (DVD 4.12). Some hammers have a protrusion at the rear called

a hammer spur (DVD 4.13). This protrusion allows the hammer to be pulled

back into a single-action firing condition by the shooter’s thumb, or to

provide greater ease in allowing the hammer to be brought out of single-

Hammerwith Firing Pin Selector

Prawl

Grip

Butt

TriggerGuardSpur

Regardless of action, firearms can come in various sizes. Both of these firearms are single shot, single action. The overall configuration is the same. Pulling back on the trigger guard spur opens the barrel action to allow the firearm to be loaded.

TriggerGuard

Trigger Forend

Muzzle

Front SightBarrelRear Sight

FIGURE 4.3. Single-shot, single-barrel handgun.


action firing condition to one in which the hammer is in an at-rest or safety

position.

Hammerless. Some firearms have a striker system rather than a hammer (DVD

4.14). On others, the hammer may be concealed in the internal mechanism

of the firearm. When the hammer is not visible, it typically is referred to as

being hammerless, even though the hammer may be present internally (DVD

4.15).

Firing Pin. Usually a metal rod that is attached to the face of the hammer or in

the frame of the firearm at a place where the hammer can contact it (DVD

4.16). The firing pin transfers force to the ignition system of the cartridge.

The firing pin sometimes is referred to as a striker.

Trigger. The part of a firearm that is moved manually to cause the firearm to dis-

charge (DVD 4.17). Triggers can have different surface textures, thicknesses,

and styles. There are two common styles of triggers: the swing or pivot (com-

monly revolver) style and straight pull style (commonly semiautomatic—i.e.,

Colt 1911 A1). Revolvers, such as Smith & Wesson and Colt, and many semi-

automatic handguns have a curved bar or lever that swings back in a short pen-

dulum motion. The individual’s hand is held high up on the rear of the gr52ip

to a protrusion called the prawl. Although the arc is short, shooters often do

not understand that the rearward pull is actually going upward at the end of the

stroke. On typical revolvers, the rearward trigger pull provides the energy to

work all of the moving parts (i.e., move the hammer rearward compressing the

mainspring; rotate the cylinder into shooting position, etc.). The trigger then

disengages the trigger from the hammer, allowing it to move forward, caus-

ing the revolver to fire and the parts of the action to go to a rest position. On

semiautomatics, such as the Colt 1911 and its clones, the trigger moves straight

back and forth, sometimes on a grooved path or track inside the frame. This

allows for a different position of the hand on the grip with a trigger pull that

beginners often find more comfortable than with a revolver.

Safety. A mechanical device that is designed to prevent the firearm from dis-

charging (DVD 4.18). Safeties can be either active (requiring a particular

manual movement of a part) or passive (automatically disengaged by normal

hand position and pressure on the trigger of the firearm). Firearms may have

no safety, no visible safety, or single or multiple safeties, and the safety(s)

may be external or internal. Some safeties appear similar but operate differ-

ently. For example, on the Mark 22/45 Mk III, to put the safety on, you push

a button-shaped lever up; on the Smith & Wesson Model 411, you push the

lever down to put the safety on. Another nonobvious example is two guns that

appear essentially to be identical; they are the original Ruger single-action

handgun models and the new model Ruger single action. A major change

to the new model single actions was the addition of an internal transfer bar

safety system. To Ruger’s credit, they have recalled all of their beginning sin-

gle actions to retrofit the transfer bar safety system at tremendous cost to the

company and no cost to the consumer. Although the transfer bar is a passive

safety system, one cannot look at the old firearm and tell if it has been altered

to the new safety system. (Authors’ note: Unless otherwise specifically noted,


further discussion of Ruger single-action firearms in this book is of the new

models with the transfer bar system, rather than first models.)

FRAME NOMENCLATURE

Grip(s). The handle of a firearm (DVD 4.19). Some are an integral part of the

frame that cannot be removed. Others are one, two, or multiple pieces—

usually panels that can be removed and replaced. Many firearms have

multiple size grips that are available to better fit the shooter’s hand. It is

important for safe and accurate handling of the handgun to insure that the

grip is the proper size for the shooter’s hand.

Back Strap. The metal strip that is at the rear of the frame where the hand is

placed on the grip, usually part of the frame (DVD 4.20). It may be exposed

or hidden under the grip. Not all firearms have this part. For example, Don

Wesson revolvers and Glock polymer semiautomatics do not have either a

back or front strap. The forward and rear portion of the grip(s) provides the

support that normally would be provided by the back and front straps.

Butt. The bottom part of the grip or grip frame (DVD 4.20).

Front Strap. The metal strip that is in the front of the frame where the hand is

placed on the grip, usually part of the frame (DVD 4.20). It may be exposed

or hidden under the grip. Not all firearms have this part.

Trigger Guard. A part of the frame that goes around the trigger to prevent

accidental discharge when dropped and to protect the trigger (DVD 4.21).

When there is no trigger guard, the trigger is described as a spur trigger if

there are no protrusions from the frame protecting the trigger (DVD 4.22).

There have been some handguns that, when the hammer was cocked, the

trigger extended downward out of the frame, totally unprotected.

SINGLE SHOT–MULTIPLE BARRELS

Single-shot, multi-barrel handguns are a variation of the single shot, single barrel,

designed to add more firepower to the individual shooter (Figure 4.4; DVD 4.23).

The firing pin system often rotates a single firing pin (DVD 4.24), or alternates

between multiple firing pins (DVD 4.24a and 4.24b), to align and fire the next car-

tridge in the subsequent chamber/barrel. An example of a handgun that alternates

between multiple firing pins is the Davis Model D9. On this and similar handguns,

if the shooter cocks the gun and fires one cartridge out of the upper chamber, cocks

the hammer again, aligning the firing pin with the lower chamber containing a live

cartridge. If the shooter then decocks the gun without firing, when the gun is cocked

a third time, it now will be back on the upper empty cartridge (fired chamber). Itis

easytoconfusewhichchamberisgoingtofire(i.e.,theloadedorunloadedone)

iftheshooterdoesnotopentheactionandcarefullyexaminewhichfiringpinis

protruding(theprotrudingfiringpinislastchamberfired).Failuretounder-

standthismechanismandbeable tocheck itappropriatelycould leadtoan

unintendeddischarge.Likewise,itisverydifficulttoeithercountorremember

whichchamberisgoingtofirenext.


These handguns have many of the same parts as the single-shot handgun above, but with multiple barrels and chambers. Also, extractors or ejectors have to remove multiple cartridges rather than a single cartridge.

REVOLVER (DOUBLE ACTION)

A revolver is a firearm that holds its ammunition in a cylinder that rotates. A cylinder

typically has five or more chambers that hold the cartridges. A double-action firearm

is one in which all the parts are moved into place to fire by a single pull of the trigger.

The trigger can perform two functions—to cock as well as to release the hammer

(Figure 4.5; DVD 4.25).

Frame Nomenclature

Chin. The part of the frame forward of the trigger guard that is curved upward

(DVD 4.26).

Top Strap. A piece of metal bridging the front part of the frame to the frame’s

rear to provide strength to the frame (DVD 4.27). The top strap also provides

some shielding to the shooter in the event of a catastrophic failure. Revolvers

that have a top strap are generally referred to as a solid frame revolver.

Breech Face. The portion of the frame that is against the cartridges and sup-

ports them in the chambers (DVD 4.28).

Prawl. The bend in the frame at the rear of the firearm and above the grip

(DVD 4.29).

Pressure Plates. The protrusion from the frame behind the cylinder that supports

the cartridges, keeping them from falling out of the chambers (DVD 4.30).

Hammer

Grip

Butt

Trigger

Muzzles

Front Sight

Barrels

FIGURE 4.4. Single-shot, multiple-barrels handguns.


Barrel Nomenclature

Forcing Cone. A funnel cut into the rear portion of the barrel that allows the projectile to be funneled into the barrel, as the opening in the cylinder does not always line up perfectly with the barrel (DVD 4.31).

ACTION NOMENCLATURE

Cylinder Gap. The gap between the cylinder and the barrel that allows the cylinder to rotate without rubbing against the barrel (DVD 4.32).

Crane. The part of a revolver that allows the cylinder to swing out to facilitate loading and unloading (DVD 4.33).

GripScrew

Grip

Hammer Spur

Hammer

TriggerGuard

Trigger

Front Sight

BarrelFlutes

Cylinder

Cylinder Release

Cylinder LockNotches

CylinderLock

CylinderGap

TopStrap

Rear Sight

Prawl

Ejector/Extractor Rod

FullShroud

(Ejector orExtractor Rod

Housing)

Crane

Pressure Plate Vent RibMuzzle

Chin

Forcing Cone

Chambers

Frontstrap(Underneath

Grip)

Backstrap(Underneath

Grip)

Ejector, Ratchet, and Stem

Butt

Side Plate

FIGURE 4.5. Double-action revolver.


Cylinder Release. Often, the straight pull style trigger rides in a track or chan-nel inside the frame, moving in a straight line. A release latch that allows the cylinder to be unlocked from the frame (DVD 4.34). The cylinder release latch can operate differently on different brands of firearms. It normally is

found behind the cylinder on the left side of the firearm. Typically, on Smith

& Wesson style revolvers it pushes forward to release; on Colt style revolv-

ers it pulls straight back; on Ruger style revolvers it pushes straight into the

frame. One exception to the general rule for location is the Dan Wesson

style revolver that has the release forward of the cylinder on the left side,

and it pushes downward. A few types of revolvers are opened by pulling the

extractor rod forward. Some revolvers, such as the Taurus .454 Casull, have

more than one latch; this is to insure that the cylinder stays in place with

powerful ammunition.

Cylinder. The part of the revolver that contains multiple chambers and rotates

(revolves) in the frame (DVD 4.35). The cylinder may revolve in one direc-

tion to the left (counterclockwise, e.g., Smith & Wesson, Taurus, Rossi,

Ruger) or the right (clockwise, e.g., Colt).

Extractor or Ejector Rod. A metal rod that protrudes from the center front

of the cylinder, through the cylinder, attaching to the extractor or ejector

(DVD 4.36).

Extractor or Ejector. A star-shaped part at the rear of the cylinder of a revolver

that extracts the cartridge cases from the chambers when the ejector/extrac-

tor rod is pushed to the rear (DVD 4.37).

Ratchet. The part of the ejector in a revolver, shaped like a notched wheel,

which rotates the cylinder when pushed by a part called the hand or pawl

(DVD 4.38).

Hand or Pawl. An internal part that protrudes from a rectangular opening,

called a window, in the breech face that engages the ratchet to rotate the

cylinder (DVD 4.39).

Window. A rectangular opening in the breech face that allows for contact

of the hand with the ratchet on the ejector/extractor to rotate the cylinder

(DVD 4.40).

Chamber(s). Openings in the cylinder designed to hold and support cartridges

(DVD 4.41). They usually are cut for specific types of ammunition. Exam-

ples of exceptions to this rule are the .38 Short Colt, .38 Long Colt, and .38

Special ammunition.

Flutes. The area cut out of the front sides of the cylinder to reduce weight or

for decorative purposes (DVD 4.42).

Lock Notches. Small arrow-shaped notches that are cut into the rear of the

cylinder (DVD 4.43). When the lock or bolt engages the lock notches, the

cylinder is held in the correct place for alignment with the barrel.

Lock or Bolt. A part that comes through the frame under the cylinder to engage

notches in the cylinder in the correct position for firing (DVD 4.44).

Main Spring. A leaf or coil spring that powers the hammer, allowing it to move

forward with force enough to cause the ignition system in the cartridge to

function (DVD 4.45).


REVOLVER (SINGLE ACTION)

A single-action firearm is one in which the hammer must be manually cocked to fire

(Figure 4.6; DVD 4.46).

Loading Gate. A hinged part attached to the frame behind the cylinder that is

opened to allow loading, and closed to keep the cartridges in place when the

cylinder is rotated during firing (DVD 4.47).

Ejector Housing. An elongated metal housing that guides and protects the

ejector rod (DVD 4.48).

Ejector Rod. A rod that, when pushed back and aligned with a chamber,

goes through the chamber and pushes out the cartridge or cartridge case

(DVD 4.49).

Axis Rod or Base Pin. A metal rod that goes through the frame and center of

the cylinder, holding the cylinder so that the chambers rotate to align with

the barrel (DVD 4.50).

SEMIAUTOMATIC (SELF-LOADING)

A semiautomatic is a firearm that uses the gasses created by the ammunition com-

bustion process to do work. Typically, the gasses are transformed into energy that

unloads the chamber, cocks the hammer, and reloads the chamber of the firearm. A

semiautomatic firearm fires one shot for each trigger pull (Figure 4.7; DVD 4.51).

The incorrect term auto pistol is often used to describe semiautomatics; an auto-

matic is one in which when the trigger is pulled, the firearm fires until the trigger is

released or the firearm is out of ammunition. Few handguns are true automatics as

they are too hard to control.

Grip

Loading Gate

HammerSpur

Hammer

Trigger Guard

Trigger

Front SightBarrelCylinderRear Sight

Ejector RodHousing Ejector Rod

Crown

Muzzle

Chin

Butt

FIGURE 4.6. Single-action revolver.


Slide. The upper portion of most semiautomatics that reciprocates (slides) back and forth (DVD 4.52). The slide has a breech face that supports the rear of the cartridge and houses other parts of the firearm, such as the extractor

and firing pin. Not all semiautomatics have a slide. For example, the Ruger

Mark Is and IIs have a reciprocating bolt inside the frame that serves the

same purpose (DVD 4.53). Slides usually have an integral breech block that

supports the rear of the cartridge.

Slide Lock or Release. On some semiautomatics, a lever that allows the slide to

be locked back (DVD 4.54). This lever may have to be manually engaged,

or it may be automatically engaged when the magazine is empty. On some

brands of firearms, like the Colt 1911, the lever is large enough to push

down with the thumb to release as well as to lock the slide open. On others,

such as the Glock line of handguns, it functions as specified by Glock to be

a lock only, and not a release.

Ejection Port. The opening in the slide that allows cartridges or casings to be

ejected from the firearm (DVD 4.55).

Grip

Semi-automatic Handgun

Hammer

Safety

Tang

TriggerGuard

Trigger

Front Sight BarrelSlide

Slide Release Rear Sight

Ejector Port

ChamberExtractor

MagazineRelease

Magazine

Ejector

Crown

Muzzle

RecoilSpringGuide

Butt

Lanyard Ring

FIGURE 4.7. Semiautomatic handgun.


Tang. The pointed portion at the end of the frame and above the grip on a semi-automatic handgun, similar to the prawl on the revolver (DVD 4.56).

Chamber. The opening at the rear of the barrel of a semiautomatic that holds the cartridge in the correct place for firing (DVD 4.57).

Extractor. The extractor on a semiautomatic is a hook-shaped device, usually

on the right side of the slide behind the ejection port (DVD 4.58). It usually

is pinned to the slide, with a spring located at its rear that allows the hook

to press tightly to the rear of the cartridge. When the slide comes to the rear,

it pulls (extracts) the cartridge from the chamber.

Ejector. A fixed bar that stops the cartridge from coming back, at a certain

point disconnecting it from the extractor and forcing the case or cartridge

out of the firearm through the ejection port (DVD 4.59).

Firing Pin as Ejector. On some (usually cheaply made) firearms, the firing pin

protrudes from the breech face when the slide is fully to the rear, acting as

a fixed point and taking the place of the ejector (DVD 4.60).

Magazine. A container designed to hold ammunition in the firearm. It gener-

ally has four parts: the body, floorplate, follower, and internal spring (Fig-

ure 4.8; DVD 4.61). The floorplate keeps the spring from leaving the bottom

of the body. The follower traps the spring in place at the top and follows

the cartridges up the body. Magazines can hold different numbers of car-

tridges, aligned either one on top of another, or staggered. Most magazines

are separate units that can be taken out of the firearm; a few are built into

the internal mechanism and are loaded with a clip. A clip usually is a strip

of metal that facilitates the loading of a magazine, or internal magazine on

some firearms, by holding cartridges in alignment.

Magazine Release. A control that, when activated, will unlock the magazine

from the firearm (DVD 4.62).

Decocker. A lever found on some semiautomatics that decocks the hammer

without discharging the firearm (DVD 4.63).

Double-StackMagazine

Single-StackMagazine

Extended Floorplate

FIGURE 4.8. Magazines for semiautomatic handguns.


Magazine Well. The place into which the magazine is inserted, usually in the grip, but sometimes forward of the grip, such as in the 1896 Mauser Broom-handle or the Intratec Tec 9 (DVD 4.64).

HANDGUN VARIATIONS

There are many variations of handguns. The following are relatively common varia-tion types.

REVOLVER, TIP UP

A release (barrel catch) on the frame allows the cylinder, barrel, and forward por-tion of the firearm to move up to allow for loading and unloading. This was a com-

mon early design with millions having been produced. Because of a shooting sport

referred to as “Cowboy Action Shooting,” this style, as well as the top break revolver

(shown later), has had a recent resurgence in popularity and use. Most of the older

firearms from the early 1900s using these two designs use lower powered cartridges.

It is not unusual to come across these types of firearms in shooting cases because of

the large quantity that were manufactured (Figure 4.9; DVD 4.65).

REVOLVER, TOP BREAK

A release (barrel catch) on the frame, or at the rear of the top strap, allows the cylin-

der, barrel, and forward portion of the firearm to move downward to allow for load-

ing and unloading. Beretta Firearms Company also makes a semiautomatic pistol

with a barrel catch that allows the rear of the barrel to pop up to facilitate loading and

unloading. Thompson Center has designed a modern firearm that can use modern,

more powerful ammunition, but uses the trigger guard as a release. (Figure 4.10;

DVD 4.66).

Grip

Hammer

Cylinder

Trigger

Front Sight

Barrel

Barrel Release

Muzzle

Butt

FIGURE 4.9. Tip-up revolver.


BOLT-ACTION HANDGUN

This is a manually operated action in which a bolt with a handle in line with the bore of the firearm is moved back and forth (Figure 4.11; DVD 4.67). The bolt is manipu-

lated back (open) for loading by pulling the handle up and then to the rear, and for-

ward and down to close the firearm for firing. The bolts can have lugs to lock the bolt

in place for firing. An example of this style of firearm is the Remington XP100.

Grip

Hammer

Hammer Shroud

TriggerGuard

Trigger

Front Sight

BarrelBarrel Catch

CylinderExtractor

Rear Sight

Prawl

Prawl

Muzzle

Butt

FIGURE 4.10. Top-break revolver.

Grip

Stock

Safety

Scope (Optical Sight)

Trigger

Bolt

Bolt Handle

Front SightBarrel

Muzzle

Forend

Butt

FIGURE 4.11. Bolt-action handgun.


GAS-OPERATED SEMIAUTOMATIC

This action is one in which some of the gasses produced by the cartridge, when fired,

are siphoned off through a hole in the barrel and direct the force of the gas to the

slide or bolt, using them to cycle the action (Figure 4.12; DVD 4.68).

MULTIPLE NAMES FOR THE SAME PART

It is important to understand that manufacturers often have names that are different

for parts that operate basically the same. Common user or gunsmith names can be

different from the name that a manufacturer may use. Examples of this are as shown

in Table 4.1. Standardization of names would eliminate this unnecessary confusion.

Although it is important to know the common name, research into the manu-

facturers’ terminology often is helpful in understanding where the parts go and how

they function.

ACTIONS

Revolvers and semiautomatics also can be classified in three different action types:

Singe Action (SA), Traditional Double Action (DA), and Double Action Only (DAO).

SINGLE ACTION (SA)

A single-action (SA) firearm is one in which the hammer has to be manually cocked

and is released by pressure placed on the trigger (DVD 4.69). When the hammer is

cocked back on a revolver, the cylinder rotates, aligning a cartridge with the barrel.

When the trigger is pulled, the hammer is thrown forward by the force of the main-

spring. No other part typically moves at the time of firing. Single actions require

little force to discharge the firearm (3.5 to 5 pounds), and little rearward movement

(1/8 inch or less) of the trigger to fire. The hammer does one action: It falls forward

to fire the firearm. When the hammer is in the rest position (down against the frame),

Grip

Hammer

Trigger

Tang

Slide Ejection Port Piston Vent Rib

Trigger Guard

Gas Adjust Ring

Front Sight

Barrel

Rear Sight

Muzzle

Butt

FIGURE 4.12. Gas-operated semiautomatic.


the trigger can be pulled, but the firearm will not fire. The manual cocking of the

hammer puts all of the parts into the correct firing position for firing.

DOUBLE ACTION (DA)

A traditional double-action firearm (DA) is one in which the trigger performs two

functions, to cock and release the hammer. The trigger, when pulled, moves the parts

into the correct firing position and, at some point, impels the hammer forward to fire

the firearm (DVD 4.70). The finger provides all the energy to rotate the cylinder of a

revolver into firing position, and to place all of the internal parts into firing position.

A double action’s trigger typically requires more force exerted on it (5 to 12 pounds)

and a longer pull (approximately 1/2 inch). The hammer is making, in effect, two

motions: one going back until it reaches its release point and another going forward

to fire. A traditional double-action pistol can be hand cocked into single-action mode

as well, giving the firearm two different trigger pulls.

DOUBLE ACTION ONLY (DAO)

Double-action only (DAO) firearms can only be fired in double action. They will not

cock back into a single-action mode (DVD 4.71). Sometimes, this is accomplished

by altering the internal fire control components or by making the hammer internal.

Often, handguns are encountered without the hammer spur, or hammer spur reduced

greatly in size, but with the hammer still visible. Handguns that have the hammers

or spurs still visible can sometimes be cocked into single action, but with more dif-

ficulty. The main reason for the reduction or concealment of the hammer or hammer

spur is to keep them from snagging clothing when drawn.

OPERATION, LOADING, UNLOADING, SAFETY

REVOLVERS—DOUBLE ACTION

The double-action revolver is one of the most common types of handguns. Usually,

the trigger is farther than halfway from back to front in the trigger guard. Many have

a swing-out cylinder (DVD 4.72). This allows for easy access to all of the chambers

at one time by simply activating the cylinder release latch and swinging the cylinder

out. When the ejector rod is pushed, the ejector star pushes the cartridge cases out of

TABLE 4.1.

Different names for the same part

Ruger Colt Smith & Wesson Common

Crame Crame Assembly Yoke Crame

Cylinder Latch Bolt Cylinder Stop Lock

Crame Latch Latch Thumb Piece Cylinder Release

Pawl Hand Hand Hand

Hammer Dog Hammer Strut Sear DA Sear


the chambers (DVD 4.73). By pointing the muzzle up, gravity helps in ejecting the cartridges or casings from the cylinder. If the muzzle is pointed down, a cartridge may get under the ejector, thereby disabling the firearm because the ejector is too

far from the cylinder (DVD 4.74). If the ejector is not in the cylinder correctly, the

cylinder will not be able to fit back into a correct position in the frame. This type of

malfunction takes time to clear and is relatively common with beginning shooters.

Once the cylinder is opened, the revolver generally is safe, as the firing mechanism

is not able to reach the cartridges. Thisisasimpleproceduretomaketherevolver

safer;removalofthecartridgesinsuresthatthefirearmcannotbefired.

To load the revolver, cartridges are loaded one at a time into each chamber, or

a loading device, such as a speed strip, speed loader, or moon clip, may be used to

load faster. To fire the revolver, cartridges must be placed into the chambers and the

cylinder closed, insuring the lock has engaged the lock notch on the cylinder, thus

aligning the cylinder correctly to the barrel and holding it in place during the firing

process (DVD 4.75).Itisimportanttonotethat,forallthreetypesofrevolvers

(SA,DA,andDAO),thechamberunderthehammerisnottheonethatwillbe

firedwhenthehammerisforward. This is because of the cylinder rotating when

the hammer is pulled back.

Oncethecylinderisloaded,itmaynotbepossibletotellwhetherornotit

isloaded (DVD 4.76). Somerevolversallowyoutoseetheedgesofacartridge

fromtherearsidesofthecylinder,butthisdoesnotletyouseeifthecartridges

areloadedoriftheyareemptycases (DVD 4.77). Noristheviewofthetopor

bottomcartridgeunobstructed.Somerevolvershaverecessedchambers that

donotallowforanyviewofthecartridgecasings (DVD 4.78). Itisnotuncom-

monforashootertoopenacylinder,lookquicklydownatthechambers,and

notnoticethatitisstillfullyorpartiallyloaded,iftotalattentionisnotgivento

insuringthattherevolverisempty. Occasionally, the color of a cartridge case will

mimic the color of the background of empty chambers or the gun itself. An example

of this would be a nickel (silver-colored) cartridge case with a stainless steel (usually

silver) firearm (DVD 4.79). Whenoneisverifyingthatafirearmisunloaded,itis

criticalforsafetythatone’sfullandundividedattentionisgiventothistask.

The DA revolver is one of the easiest firearms to make mechanically safe. When

the cylinder is opened, a quick and easy task requiring little strength, the firearm

cannot fire. As stated previously, a traditional double action (commonly referred to

simply as double action) is a firearm that can be fired in two different modes—single

or double action. In double-action mode (that is, without cocking the hammer), one

could start to pull the trigger of a revolver and decide not to shoot, relaxing slowly

on the trigger. Typically, the cylinder would start to move to the next chamber but

stop its movement when force is removed from the trigger. Sometimes, the cylinder

has to be moved to the next index point (locking notch) manually in order to fire the

next cartridge. It would not be likely that the firearm would fire by relaxing the trig-

ger pull and slowly letting out the trigger. In the same situation, single-action mode

presents a different problem in that all the parts are in sequence to fire with only a

short trigger pull. This is because the hammer is in the cocked position with a com-

pressed spring ready to release it with force. The cocked hammer must be grasped

and held tightly, usually by pinching it with the thumb and forefinger, as the trigger


is depressed—allowing the hammer to go slowly forward.Itisnotuncommonfor

ashootertolosecontrolofahammer,allowingthespringtopushthehammer

withenoughforcetocausedischarge. The motion picture industry has provided many bad examples of releasing the hammer using only the thumb to lower it into place. Although this has become commonplace for many advanced shooters, it is not the safest manner to decock a firearm. Handsorfirearmsthatarewet,oily,or

coldmakedecockingsafelymoredifficult.Extracautionneedstobetaken. The

Hollywood version of closing the cylinder of a DA revolver by jerking the firearm

to the side also should be avoided, as this will damage the crane and bolt. Rarelyis

themake-believevisualentertainmentshowcasingfirearmsagoodexampleof

properorsafeuse.

DA revolvers do not typically have manual safeties, but they do have passive

internal mechanisms that decrease the chances of inadvertent discharge if the fire-

arm is dropped. Usually, when there is a manual safety on a revolver, whether it is

single or double action, it is generally a poorer-quality firearm, often made with

inferior-quality materials. The two most common passive safety systems are the

hammer block (DVD 4.80) and the transfer bar (DVD 4.81) systems, found in both

single- and double-action revolvers. Smith & Wesson style firearms use the hammer

block system. The hammer block system has a bar that blocks the hammer from

going forward until the trigger is pulled. When the trigger is fully pulled back, the

hammer block drops down and allows the hammer to go farther forward to contact

the firing pin. When the trigger is released, the block goes back into the blocking

position between the hammer face and the firing pin. The transfer bar system works

basically the opposite: When the trigger is fully depressed, the transfer bar goes

up between the hammer and the firing pin. The hammer springs forward, impact-

ing the transfer bar, which then transfers the energy of the impact to the firing pin.

Upon release of the trigger, the transfer bar drops down, thereby ending any contact

between the hammer and firing pin. The transfer bar system has been in use since

1892 by Iver Johnson. In both of these systems, the finger becomes the manual safety

on the firearm. With no finger on the trigger, there is little likelihood of a discharge.

Unfortunately,millionsoffirearmshavebeenmanufacturedwithoutanysafety

system. Beforetheseinnovations,thehammerwouldrestonthefiringpin.A

sharpblowto thehammerordroppingthefirearmcouldcauseadischarge.

Common practice when carrying older firearms that had no internal safety sys-

tems was to leave one chamber empty and rest the hammer on that empty chamber.

Becausethesepassivesystemsareinternal,itisdifficulttodeterminewhether

theyarepresentornot. Sturm Ruger and Company (Ruger) originally produced

many SA firearms without a safety system but currently offers to retrofit a safety sys-

tem into their guns made in the 1950s at no cost to the owner. Many other companies

that have produced firearms without safety systems are no longer in business, and it

is not possible to retrofit these firearms. Regardlessofwhatsafetysystemmayor

maynotbepresent,theseareonlymechanicaldevices.Allmechanicalsafety

devicescanfail.Mechanicalsafetydevicesmakefirearmssafer, notsafe.


REVOLVERS–SINGLE ACTION

The typical single-action firearm is distinctive in that the ejector housing appears

(usually) on the right-side bottom of the barrel and has a finger tab device protruding

from the housing. The housing usually is a few inches long and almost looks like

a second barrel from the side. Often, the trigger appears farther back in the trigger

guard than on DA-type revolvers (DVD 4.82). This is because pulling back on the

hammer moves all of the parts into place for firing; the trigger only needs to move

a small distance (generally 1/10 of an inch or less) to release the hammer. In DA

revolvers, firing in double action, all of the fire control parts are communicating

with the trigger. The force applied by the finger on the trigger is pushing all of the

parts into firing position. Single-action firearms are loaded and unloaded by gaining

access to the chambers through a loading gate that normally opens on the right rear

side of the revolver, behind the cylinder. There usually is a notch for the finger to

facilitate opening of the gate. The loading gate may be flat or curved, following the

contours of the frame. On most SA revolvers, the hammer can be in any one of four

positions (DVD 4.83):

1. At rest on the frame, usually resting and pushing the firing pin forward.

2. A position, often referred to as the safety notch, that holds the hammer

slightly off the frame and away from the firing pin.

3. The half-cock position, which typically is engaged to allow the cylinder

to spin freely for loading and unloading purposes. (The saying “going off

half cocked” should remind one that the hammer has enough force to cause

ignition in the cartridge in this position.)

4. The cocked position, in which the hammer, in conjunction with the com-

pressed main spring, has enough force that, when released, provides suf-

ficient striking force to cause ignition in the cartridge.

Many SA revolvers require the hammer to be in the half-cocked position for loading

and unloading. When the loading or unloading (i.e., the placing or removing of one

cartridge at a time into each chamber) is complete, the hammer is pulled to full cock.

Next, the hammer is grasped and the trigger pulled, allowing the hammer to slowly

ease down to the frame and then pulling it back to the safety cock notch. Ruger

firearms are an exception to this general rule: When the loading gate is opened, the

hammer will not move and the cylinder will spin freely. This allows the firearm user

to load or unload without having to manipulate the hammer or trigger (DVD 4.84).

Theabilitytoloadandunloadwithoutmanipulationofthehammerandtrigger

providesagreaterdegreeofsafetyinoperation.

When single-action revolvers are either fully or partially loaded, it is generally

more difficult to determine if the firearm is loaded. Iftheloadinggateisopened

andthechamberthatisinviewisempty,itisnotsafetoassumeallofthecham-

bersareempty.Eachchambermustbeindividuallyinspected.Becausethecyl-

indercanrotaterelativelyfast,itispossible,ifoneisnotgivinghisorherfull

attentiontoinsuringthatthefirearmisunloaded,tomissacartridge. Think-

ingafirearmisunloadedwhen,infact,itisloadedisanobviouslydangerous


situation.Checking the chambers multiple times is relatively easy and provides a greater degree of safety. In unloading the firearm, loaded cartridges usually will fall

out with ease when the chambers are clean and the muzzle is pointed upward. Fired

cartridge cases expand when fired; to remove fired casings or stuck live cartridges,

the chamber must be aligned with the open loading gate and the finger lever pro-

truding from the ejector housing pushed back toward the cylinder. The ejector rod

will contact the inside back of the casing or the projectile on a loaded cartridge and

push it out through the loading gate opening. As with the DA revolver, pointing the

muzzle up allows gravity to assist in ejecting the cartridge cases from the firearm

(DVD 4.85).

REVOLVERS–DOUBLE ACTION ONLY

Double-action only firearms, although not as common as traditional DA revolvers,

basically operate, load, and unload the same as the DA revolvers. The difference is

DAO revolvers are not designed to cock into single action. Normally, DAO revolvers

have a hidden hammer or have no hammer spur, which aids in a quicker draw when

carried concealed, as the hammer will not easily catch on clothing. The trade-off for

the quicker draw is that the shooter always has a longer, heavier pull to discharge

the firearm. This adds to the difficulty of keeping the sights aligned on the intended

target. The more movement the finger has to make on the trigger, the more likely the

barrel will move. Although correct practice and building up hand and finger strength

will help to maintain accuracy, double action will generally be harder to control than

single action.

SEMIAUTOMATICS

Semiautomatic (semiauto) firearms are firearms that use the energy of the expand-

ing gasses in the cartridge at the time of firing to do the work of cycling the action.

This has a number of benefits, such as faster firing and less felt recoil (kick). The

lessening of recoil allows more comfort in that the amount of pressure against the

hand, or what is referred to as “kick,” is reduced. If like caliber firearms of the

same weight and cartridge type are fired, one a revolver or single shot and the other

a semiauto, there will be less force felt by the semiauto. Many semiauto handguns

hold more cartridges than revolvers, an important consideration in both competition

and combat applications. Semiauto firearms are relatively easy to differentiate from

revolvers because they have no cylinder. Like revolvers, semiautos can be single

action, double action, or double action only. It is common for there to be confusion

about what is a semiauto versus what is a true automatic, which appears to be based

on ignorance or purposeful political propaganda. A semiauto typically fires one shot

for each trigger pull. The gasses that are created from the combustion of the propel-

lant (usually smokeless gunpowder) in the cartridge provide the energy to push the

empty cartridge case from the firearm by pushing the bolt or slide backward, pulling

the cartridge case from the chamber and ejecting it from the firearm, cocking the

hammer or striker, and loading a new cartridge into the chamber. In DAO semiauto

handguns that have a hammer, it is decocked automatically after loading or firing.

A true automatic firearm fires continuously when the trigger is depressed until the


firearm is out of ammunition, malfunctions, or the finger stops pulling on the trigger.

Although there are a few true automatic handguns, they are not easy to control and

are relatively rare today.

METHODS OF OPERATION

There are five methods of operation in semiauto handguns:

1. Blowback (inertia locking)

2. Delayed or retarded blowback

3. Blow forward

4. Gas

5. Locked breech (recoil)

Three of these are relatively common today: the blowback, locked breech, and gas.

Blowback. Blowback firearms are usually designed to shoot lower-powered

cartridges—.380 caliber and below. The exception to this rule is firearms

currently manufactured by Hi-Point, who have developed blowback fire-

arms in larger calibers by increasing the weight of the slide and using larger

recoil springs. This also was the method used by Astra on the model 400

and on a few other discontinued higher-caliber blowback handguns. The

blowback system is basically designed to take the gas pressure created in

the chamber from the combustion of the gunpowder and use it directly by

pushing the cartridge back against the slide to work the action (i.e., to fire,

eject, cock, reload, and close the action of the handgun). This is relatively

simplistic science, based on Newton’s third law of motion: For every action

there is an equal and opposite reaction. The projectile is pushed forward

out of the barrel and the cartridge case is pushed to the slide until ejected

out of the firearm. The blowback system is relatively common and found

on many inexpensive, low-caliber firearms. When more powerful ammuni-

tion is used, the cartridge case must be supported until the pressures have

subsided to a safe level. With the delayed blowback, there is a mechanical

delay built into the action that does not lock the action but slows the car-

tridge ejection system down long enough for the gas pressure to drop to a

safe level. The delayed blowback system is best illustrated by the Heckler &

Koch pistols that use locking rollers that delay the bolt to slow the ejection

process.

Blow Forward. A system in which the breech does not move but the barrel

moves forward. An example of this is the Steyr Mannlicher M1894.

Gas. The gas-operated system, while common in rifles, is not very common in

handguns. It functions by siphoning off gas from a small hole in the barrel

and diverting it, usually through a tube, to operate the bolt or slide. Examples

of this would be Magnum Research’s Desert Eagle or the Wildey firearms.

Locked Breech. By far the most common system of operation in larger-caliber

semiautomatic handguns is the locked breech system. When the firearm is


fired, the barrel is locked to the slide. As the projectile is pushed out of the

barrel, the gasses are also pushing the cartridge case against the breech face

of the slide, and, therefore, the slide is pushed to the rear. The barrel travels

a small distance back with the slide until the pressures drop to a safe level.

At this point, the barrel drops down, unlocking itself from the slide and stay-

ing with the frame. The slide continues its travel rearward, completing the

extraction, ejection, reloading, cocking, and closing process (cycling).Semi-

automatic handguns typically have a detachable magazine. Often a shooter

will carry multiple magazines to be able to reload the firearm quickly. As

cartridges are loaded into the magazine, a spring inside is compressed; the

more cartridges you place into the magazine, the harder the next one is to

load. There have been tools developed to aid in fully loading the magazine.

Once the magazine is loaded, it can be inserted into the firearm. This is done

by placing the magazine, cartridge side up and projectile toward the front of

the firearm, up into the magazine well. The magazine well usually is in the

handle (grip) of the firearm, although there are some that have it forward of

the trigger guard (DVD 4.86). If the magazine does not engage an internal

latch, it can fall out of the firearm, so it must be pushed in with vigor. If the

magazine is fully loaded and in the firearm, but no cartridge is placed in the

chamber, it cannot fire. In order to put the firearm into firing order, a car-

tridge must be placed in the chamber by working the slide or bolt.

PLACING THE SEMIAUTOMATIC IN BATTERY

When a cartridge is in the chamber and the slide or bolt properly closed on the car-

tridge, the firearm is said to be in battery. This can be accomplished three ways:

1. The action can be opened by pulling back on the slide or bolt, locking the

bolt into place, placing a single cartridge in the chamber. When the bolt

is closed and the safety is placed in fire position, the firearm will fire that

cartridge, whether a magazine is in the firearm or not. If the magazine is

not in the firearm, only one round can be fired. If the magazine is loaded

and placed into the firearm when the chamber is loaded, it will continue

to fire and reload the chamber until the firearm is empty (an exception to

the firearm firing without a magazine would be a firearm that has a maga-

zine disconnect that stops the firearm from firing when the magazine is

removed). This manner of loading the chamber is often used, although it

puts excessive wear on the extractor. When the slide is closed on the loaded

chamber, the hook at the end of the extractor hits the rear of the cartridge

and has to force itself around the rim of the cartridge.

2. The second method is to put the magazine into the magazine well with

the slide already locked back. Either the slide is pulled fully to the rear

and released, or the slide release is depressed allowing the slide, which has

a compressed spring (called the recoil spring) exerting force against the

slide, to snap vigorously forward. The former is preferred, as the system

is designed to work with the recoil spring at full compression. The bottom


of the slide’s breechblock catches the top rim of the cartridge, pushing it forward toward the chamber. There are two bent pieces of metal at the back of the magazine called feed lips. They hold the cartridges in place until the cartridge is pushed forward past their grasp. At this point, the pressure from the magazine spring is pushing the cartridge up the breech face until the extractor engages the cartridge, holding it in place while the slide is pushing the cartridge into the chamber. When the slide or bolt is fully closed, the firearm is in battery and ready to fire. This method takes one round out of

the magazine, which can be removed, and another round placed in it to top

it off. Usually out of laziness or ignorance, shooters often load by the first

method to keep from having to pull the magazine out again to fully load it.

3. The third method is to put a loaded magazine into the firearm with the bolt

closed, and then grasp the rear of the slide or bolt, pulling it to the rear until

it can go no further, and then just release the slide. The recoil spring that

is compressed will push the slide or bolt forward, completing the process

as described earlier. Some manufacturers, such as Glock, recommend this

manner and purposely make the release small so it is uncomfortable to

close the slide by thumbing the release down. The recoil spring is set with

a certain amount of pressure when it is compressed.Tryingtoassistthe

slidebyhelpingittogoforwardusuallyaltersthetimingoftheloading

procedure,thuscausingajamtooccur. Putting in too strong a spring can

have the same effect. This type of jam or malfunction is typically a failure

to feed the cartridge into the chamber.

On many firearms, when the magazine is empty, a portion of the follower will push

up against the slide lock or release, locking the slide to the rear. Pulling the slide

back manually typically means that if the firearm has an exposed hammer, the effort

to pull the slide back is also cocking the hammer. For persons with little upper body

strength or physical disabilities, it is often easier to cock the hammer manually and

then pull back on the slide, lessening the effort needed to chamber a cartridge. When

a magazine is loaded, the cartridges keep the follower from contacting the slide

release or lock.

UNLOADING

Now that the loading process is understood, it is important to understand the unload-

ing process—not just the mechanical issues, but the physiological and psychological

issues as well. Onanyfirearm,theunloadingprocessstartswithinsuringthat

thefirearmispointedinasafedirectionandinsuringthatthedirectionremains

safe.That is, while you are physically unloading the firearm and watching the pro-

cess, ensure that no one walks in front of the muzzle while your attention is on what

you are doing mechanically. This is multitasking, and science tells us we cannot con-

sciously do two things at once as well as we can do one (see “Divided Attention” in

Chapter 2). This applies to all firearms. Semiautomatics are very unforgiving if you

make a mistake. They require more mechanical movement than DA revolvers. The

stepstounloadasemiautofirearmmustbedoneinthecorrectorder:


The safety should be placed in the safe mode (if possible: Some firearms

require that the safety be in the firing position to be able to pull the slide to

the rear for the unloading process).

The source of ammunition must be removed. This typically means that the

magazine release must be found and activated and the magazine removed

from the firearm.

While keeping the firearm pointed in a safe direction, the slide or bolt is pulled

to the rear sharply. This allows the extractor to extract the cartridge from

the chamber and the ejector to eject the cartridge from the firearm. If the

slide is not pulled sharply back, the cartridge may not be ejected from the

firearm. Holding the slide back and rotating the gun to the right side usu-

ally allows the cartridge to fall from the firearm (assuming the ejection port

is on the right, which usually is the case). It is important to note that some

slides are harder to grip than others, and some require more strength than

others. Using the shoulder muscles rather than the wrist muscles to pull the

slide to the rear will help make it easier. This is accomplished by keeping

the arms locked with one hand on the grip and the other on the slide, push-

ing forward with the grip shoulder and pulling back with the slide shoulder.

This usually provides enough energy to pull the slide back sharply enough

to insure ejection of the cartridge from the chamber.

Lock the slide to the rear and visually check the chamber and magazine well

to insure that it is empty. Physically check the chamber with the end of the

pinky finger to insure no cartridge is in the chamber. Some firearms will

not lock the slide to the rear, and the firearm must be turned to have enough

light enter the chamber so that the chamber is clearly visible.Itisimpor-

tanttoremainawareofwherethefirearmispointedatalltimes.

Note:If,beforethemagazine isremoved, theslide ispulledbackfirst,eject-

ingthecartridgefromthechamber,andthenisclosed,anewcartridgecan,

andwill,go intothechamber.Even if themagazine ispulledoutof thefire-

arm, the chamber still is loaded, and unless there is a correctly functioning

magazinesafety,thegunwillfireifthetriggerisdepressed.Thisisacommon

deadlyerror.Addedhuman issues, suchas fatigue, stress,drugs,oralcohol,

willincreasethelikelihoodoftheshooterbeingunawarewhentheprocedureis

beingdoneimproperly.

SAFETIES

In the shooting process, it is easy to say “put the firearm on safe or off safe.” In real-

ity, withsemiautomatichandguns,therearemanydifferentsafetiesthatoperate

indifferentways,locatedindifferentplacesonthefirearm. Typically, semiauto

firearms do have at least one safety, if not more. The best way to determine where

the safety or safeties are and how they operate is to read the instruction manual. If

the firearm does not have a manual, contact the manufacturer. If the manufacturer

is no longer in business, the public library or a competent gunsmith can be sources

for correct information. On current manufactured commercial firearms, the safety


may be inscribed with the words safe and fire or with a red dot showing when the firearm is in the safe position. Usually,thereddotshowingisawarningthatthe

firearmisinthefiringcondition;however,someolderfirearmsmayhavethe

reddotcovered,meaningthatitisinthefireposition.Often,theoriginalpaint

wearsoff.ForeignfirearmsmaybemarkedinalanguageotherthanEnglish.

Older firearms, as well as foreign and domestic military or law enforcement surplus

firearms, may be marked or inscribed. There are many used firearms, often manu-

factured decades ago, currently available on the resale markets that have neither

manuals nor obvious directions on the use of their safety systems. Safeties can be

active or passive, single or multiple, internal or external, overly easy or difficult to

engage. As stated previously, the locations and number of safeties can vary from

brand to brand. For example, the Colt 1911A1 (a very common style of handgun) and

its clones have a grip safety that is placed into the fire mode just by correctly grasp-

ing the grip (DVD 4.87). The grip safety is held out of the frame, disconnecting the

trigger from the sear, which interferes with the firing process. When the shooter’s

hand grips the frame, it overpowers the spring holding the safety out and allows the

trigger to communicate with the sear. This allows the firing process to progress to

the eventual fall of the hammer and firing of the firearm. They also have a manual

safety lever that disconnects the trigger from the hammer, which must be pushed

down in order for the firearm to fire. The 1911s (and A1s) style handguns also have a

manual safety lever that disconnects the trigger from the hammer. This lever must be

pushed down in order for the handgun to fire. The Glock series of pistols have what

the manufacturer claims is a three-part safety system that is disengaged to allow

the firearm to function by placing the finger on the trigger and pulling the trigger

back to fire. The basic philosophy is that if the finger is not on the trigger, the gun

will not fire. Unfortunately, firearmsaredesignedtobecomfortablewhenplaced

in thehand with thefingeron the trigger (DVD4.88). It takes extra educa-

tion,training,andefforttolearntokeepthefingeroffthetriggerandoutof

thetriggerguardtomakeinadvertentdischargeslesslikely.Anotherproblem

withmechanicalsafetysystemsisthefactthattheymaymalfunctionduetothe

effectsofwear,poordesign,orpoormaterials.

HUMAN FACTORS ISSUES RELATED TO HANDGUN DESIGN

During the previous description of handgun components and mechanics, a num-

ber of human factors/ergonomic safety design factors were highlighted. The more

important of these factors are summarized by underlying issue noted later.

NEGATIVE TRANSFER OF LEARNING FROM LACK OF STANDARDIZATION

Safetyswitchesdifferincoding,location,andmovementonotherwisesimilar

semiautomatics; similar-looking safeties can operate differently. As a result,

based on experience with a prior handgun, a person may think he or she is placing

the safety switch in the on position when, in fact, he or she is deactivating it. It is not

difficult to see how this would lead the person to unintentionally fire the handgun

(DVD 4.89).


Somesemiautomaticswillnotfirewhenthere isnomagazine inthegun;

however,manyothersstillwillfireifthereisacartridgeinthechamberandno

magazineinthegun. If a person’s experience is with a Smith & Wesson semiauto-matic, in which a magazine safety prevents the gun from firing when the magazine

is removed, and that person now is using another brand of semiautomatic, he or she

may well believe it also will not fire with the magazine removed—a misconcep-

tion often reinforced by movies. Again, it is easy to see how this mistaken assump-

tion would lead to an unintentional shooting. Smith & Wesson has developed a new

handgun, a semiautomatic model Military and Police (M&P), that is going to further

compound the problem. The gun is being marketed to military and police without a

magazine safety, and it also is being sold to the public with a magazine safety that

prevents the gun from firing with magazine removed. This is likely to lead to persons

accustomed to the civilian version, using the military and police version and unin-

tentionally firing it—potentially injuring or killing someone.

Revolvercylindersrotateindifferentdirectionsondifferentrevolvers. Thus,

changing revolvers can cause confusion as to which chamber will fire next—the one

immediately to the right or to the left of the barrel? It thus is readily foreseeable that

a person could make a wrong guess from past experience with a different revolver—

especially when under acute stress. Another possibility is that the novice shooter

may think that it is the chamber directly behind the barrel that will fire next.

Trigger forces can vary greatly among seemingly similar handguns. For

example a person accustomed to a handgun with a 5- to 6-pound pull in single action

picks up a handgun with a 2.5-pound pull, places it in single action with his or her

finger on the trigger, and swings it around horizontally and brings it to a stop. If not

consciously focusing on one’s trigger finger being out of the trigger guard, just over-

coming the inertia to stop the swing will involuntarily cause one’s finger to contract

sufficiently to fire the handgun. In some inexpensive models, the trigger pull weight

can be erratic, easily being a pound more or less from shot to shot. In a pilot study by

one of the authors, Hal Hendrick, bringing a typical semiautomatic handgun to a stop

after swinging it horizontally approximately 90° over a half-second period resulted

in applying a finger grip pressure of approximately 3.5 pounds under nonstressful

conditions. At a faster rate of making the same movement, or with a heavier hand-

gun, the pressure applied to overcome inertia would be significantly greater. Note

that the kinetic force to be overcome is KE = 1/2 mass x velocity squared. Under

stressful conditions, a person is likely to initially grip the handgun more tightly and

apply even greater pressure in overcoming inertia. In addition, given the effect of

velocity on mass, noted earlier, swinging a handgun, by itself, produces pressure on

the trigger if the person holds his or her finger on the trigger in a constant position.

With a handgun with a very light trigger pull, this action alone could cause the gun

to discharge. A more recent and thorough study of the forces to overcome inertia

and bring a handgun to a stop for several different handguns and velocities was con-

ducted by Antles & Paradis. The results of that study are presented in Chapter 10,

with further detail provided in Appendix B.

Triggertravelbeforedischargingthefirearmcandiffergreatlyamongseem-

inglysimilarhandgunsand,inthecaseoftraditionaldoubleactions,withinthe

samegunitself. Although many handguns have a trigger travel of 1/4 inch or more,


others can fire with travel of as little as 1/32nd of an inch in single action. A person

accustomed to a 1/4-inch trigger travel who picks up a handgun with a 1/32nd-inch

travel and places his or her finger on the trigger may cause it to fire before he or she

realizes it. This is particularly likely if the trigger force also is very light; and that

often is the case with handguns having a very small trigger travel (e.g., some .22-

caliber target pistols). The same problem can exist within the same double action

handgun between the trigger pull in the single- versus double-action mode.

Somerevolvershaveinternalpassivesafetymechanisms,butmanydonot.

Onecannottellfromviewingtherevolverwhetheritdoesordoesnot. Thus, a

person accustomed to a revolver he or she knows to have an internal safety mech-

anism using a different revolver lacking the mechanism might bang it or drop it,

assuming it would not fire—but it does.

NewModelRugersingle-actionrevolversdonothaveahalf-cock,butmany

othersingleactionrevolversdo.Theseotherrevolverscanfireifone’sthumb

slipsoffthehammerspur. In addition to the negative transfer of training possibil-

ity when switching from a New Model Ruger to another single-action revolver, not

having a means of preventing the firearm from being able of go off half-cocked is a

dangerous design characteristic in itself.

COST OF COMPLIANCE ISSUES

As explained in Chapter 2, cost of compliance is a well-known safety concept. Put

simply, if it takes effort to comply with a safety rule, or if wearing a piece of safety

equipment is uncomfortable or interferes with the task, persons often will not com-

ply with the rule or wear the safety equipment—particularly if they perceive the

likelihood of their being injured as being low and/or the severity of any injury being

minor. Several costs-of-compliance issues regarding handgun design, noted earlier

in this chapter, are as follows.

Lackofapositivevisualandtactileindicationofacartridgeinthechamber.

Most semiautomatics do not have an external indication of a cartridge in the cham-

ber. The operator must take the time and make the physical effort to pull back the

slide and visually inspect the chamber. Further, even if the operator does inspect the

chamber, if the slide is allowed to release and a loaded magazine is in the firearm,

a new cartridge will enter the chamber. Untrained operators are likely to (a) fail to

take the time and make the effort to inspect the chamber, and/or (b) fail to realize

that allowing the slide to go forward reloads the chamber, even if he or she subse-

quently releases the magazine from the gun. “I didn’t know the gun was loaded” is

perhaps the most frequent reason given by persons who unintentionally discharge

their firearm. From an ergonomic safety design standpoint, a positive visual/tactile

indicator is needed.

Inabilitytoseecartridgesinthecylinderchambersofmanyrevolvers. There

are three types of problems related to inability to see cartridges in the chambers of

some revolvers. First, many revolvers cover the back of the cylinder so that the car-

tridges cannot be viewed easily except by making the effort to release the cylinder,

as one does to load and unload it, and then inspecting each chamber—inexperienced

and untrained persons may not pay this cost of compliance. Alternately, the cylinders


may be countersunk, placing the ammunition where the cartridge head cannot be viewed. Secondly, if instead of taking the time and making the effort described ear-lier, one attempts to determine if the cylinder is loaded simply by looking at the front of the cylinder (an improper and unsafe procedure), it may appear that there are no cartridges in the cylinder because the cartridges are recessed and the bullet may be dark in color. Thirdly, after releasing the cylinder, trying to save time by quickly spin-ning the cylinder to check for any cartridges may cause the person to miss seeing a cartridge—particularly if the rear of the cartridge and the cylinder are similar in color (e.g., silver), thus lacking in contrast—a situation that is exacerbated by too much or too little light. Again, “I didn’t know the gun was loaded” is perhaps the most frequent reason given by persons who unintentionally discharge their firearm.

Failure to keep one’s trigger finger outside of the trigger guard. Placing

one’s trigger finger outside of the trigger guard is an uncomfortable position and

can be fatiguing over time. Firearms were made to feel comfortable with the finger

inside the trigger guard, resting on the trigger. It thus takes considerable conscious

effort and will to comply. Placing one’s finger inside of the guard on the trigger is

far more comfortable and natural but never should be done until one actually intends

to shoot. Unfortunately, almost all untrained persons, and even persons well trained

and highly experienced, will violate this rule. For example, in a well-designed study,

7 of the 34 police officers (20.59%) in the stress condition incident who pulled their

handguns out of their holsters put their finger on the trigger when they should not

have. Interestingly, when questioned about it after the incident, they all claimed they

had not realized they had done it (Heim, Schmidtbleicher, & Niebergall, 2006). Put-

ting one’s finger on the trigger has caused many unintentional shootings, includ-

ing deaths. A major ergonomic design challenge is to develop a trigger guard that

enables the shooter to rest his or her trigger finger outside of it comfortably. Such

an improvement could potentially save many lives. Note: Basic human physiology

causes all four fingers to want to move together. Working on increasing finger flex-

ibility through exercise can take away much of the discomfort of keeping the trigger

finger outside of the trigger guard.

ANTHROPOMETRIC CONSIDERATIONS

GripsandHandSize. Grips on handguns typically are made for the hypothetical

average or 50th percentile person, rather than for the range of people who can be

expected to use them. When physical handicaps or natural changes with age come

into play, the spectrum becomes even more difficult when fitting a handgun to the

person. It has been author Paul Paradis’s experience that when his students are asked

to define their preferences as to what is comfortable, they generally have little on

which to base their opinions and often choose a handgun with a grip that does not

work well for them. For example, normal finger placement on the trigger is just

beyond the last bend of the index finger. Proper finger placement depends on grip

size with respect to one’s hand size. Too small a grip size can result in a right-handed

shooter placing too much finger on the trigger, thus pulling the gun to the right when

firing. Alternately, too large a grip may result in the shooter placing too little finger

on the trigger, thereby pushing the gun to the left. Of course, the opposite of the


previous would happen for a left-handed shooter. With improper finger placement,

it is not uncommon for persons to miss hitting a target only 6 feet away. Although

this is true in a relatively unstressful target-shooting situation, it is exacerbated under

conditions of high stress, such as in a police shootout (yes, even police officers can

have handguns that do not fit their hand size). Paul Paradis investigated such a shoot-

out in which two police officers collectively shot 30 rounds at a suspect only 3 to 6

feet away, and only one round barely hit the suspect. A contributing factor may have

been an improper fit between the officers’ hands and their guns. Themajorlesson

fromthepreviouslymentionedisclear:Selectingtheproperhandgunrequires

assistancefromanexpertwhoknowshowtoselectagripthatproperlyfitsa

givenperson’shand(as well as considering other features, such as size and weight).

Whether it is a handgun for one’s home protection or target shooting, or for use by

law enforcement officers, onesizedoesnotfitall.To their credit, several major gun

manufacturers, (e.g., Smith & Wesson in their M&P Model) make an interchange-

able grip strap that enables one to readily convert the handle of the firearm to fit

different-sized hands.

Trigger Forces and Travel Requirements Versus Intended Purposes. A

handgun that is designed for safe use under highly stressful conditions requires a

higher force and greater travel than one that is designed for target shooting on a

supervised range. Whereas a 3.5 pound or lighter pull with a 1/32nd to 1/16th travel

is perfectly acceptable for target shooting on a supervised range, it is not for a hand-

gun intended for home defense or other highly stressful situations. Based on both

our experience and the existing literature, it is the authors’ opinion that both police

and home defense handguns should require a double-action trigger force of 4 to 5

pounds and a pull of approximately 1/4 inch (in order to sense movement and still be

able to stop it). However, training must match the mechanical features of the gun and

include stress training. Although these are our current perspectives, we would like to

see research carried out to validate or refine our recommendations.


DVD # Description

4.1 Barrel, frame and action

4.2 Plan view of a handgun showing front, back, left, and right

directions

4.3 Single shot, single barrel with parts listed

4.3a Side view Butler Association, Inc. Derringer with the action

open. Notice that the action swings to the right

4.4 Barrel

4.4a Barrel with ports. The ports on the end of the barrel force gas-

ses up and reduce recoil

4.5 Lands and grooves, on a cutaway

4.5a Photograph of lands and grooves in a barrel. There are eight

lands and grooves twisting in a counterclockwise direction

(left-hand twist)


4.5b Cross section of rifling—polygonal rifling on left, cut rifling on right

4.6 Muzzle4.7 Crown on a flintlock pistol4.7a Crown on a single shot. Notice the paint-like finish on the

muzzle and barrel

4.7b Crowns on multi barrel handguns

4.7c Colt revolver crown

4.7d Crown on a semi auto

4.8 Chamber

4.9 Front sight

4.9a Front sight multi barreled handgun

4.9b Front sight

4.9c Sights on a mini revolver

4.9d Front sight

4.9e Smith and Wesson revolver with modified adjustable front

and rear sight. Both the barrel and the sight bar on top are

after market alterations of the revolver

4.9f Front sight, orange dot

4.9g Front sight, high visibility. This style of high visibility sight is

a lot brighter than painted-on sights

4.9h Front sight, red ramp, on Smith and Wesson barrel

4.10 Rear sight

4.10a Rear sight, adjustable. This rear sight can be adjusted left or

right (windage) or up and down (elevation)

4.10b Rear sight, white outline

4.10c Rear sight, white outline (variation)

4.10d Rear sight, fixed

4.10e Rear sight, semi adjustable (left and right) in dovetail groove

4.10f Rear sight, notch cut into hammer (hammer is down in fired

position)

4.10g Rear sight, 2 dot

4.10h Rear sight, white dots (variation)

4.10i Rear sight, white post

4.10j Rear sight (fixed), semi auto

4.10k High visibility sights

4.10l Optical sight (scope)

4.11 Extractor-ejector. This small button under spring pressure aids

in extracting and ejecting the cartridge or cartridge case.

4.11a Extractor-ejector

4.11b Extractor-ejector—hinged Derringer (extractor out). This is a

manual extractor-ejector

4.12 Hammer

4.12a Exposed and shielded hammers

4.13 Hammer spur

4.13a Hammer spur on a double action (DA) revolver


4.13b Hammer spur on a DA revolver4.13c Hammer spur on a mini revolver4.14 Striker mechanism. In a striker system firearm, the firing pin

is held in place with a compressed spring behind it by a small

protrusion (sear). When the trigger is pulled, the sear is pulled

down out of the way, allowing the firing pin to spring forward,

starting the ignition process in the cartridge. An example

would be the Raven MP 25, .25 ACP, and the current High-

point firearms

4.15 Hammerless Iver Johnson revolver

4.16 Firing pin on hammer of a Smith and Wesson Revolver

4.16a Firing pin

4.16b Firing pin is in the frame on this Taurus revolver

4.17 Trigger

4.17a Trigger, retractable

4.17b Trigger, narrow and smooth

4.17c Trigger, wide with serrations

4.18 Safety. The trigger safety in this Iver Johnson Arms and Cycle

Works revolver was first manufactured in 1892

4.18a Safety, trigger safeties, old and new, no appreciable

difference

4.18b Safety on semi auto AMT “Backup”

4.18c Safety, semi auto variation, push-down to fire

4.18d Safety, semi auto

4.18e Top Hipoint handgun safety pushes up to engage safety; bot-

tom Smith and Wesson safety pushes down to engage safety.

4.18f Safety, Dickson Special .32 caliber, made in Spain

4.18g How does the safety work on this firearm? This warning is

useless when the company is out business

4.18h Both of these handguns were made by the same company, but

manufactured by different companies. Notice that the safeties

are in different positions!

4.18i Safety on this 1907 Savage also acts as a slide lock

4.18j Two Ortigies semi autos with two different safety systems

4.18k Multiple safeties on semi auto

4.18l Some Springfield Armory handguns, as well as Glock, have a

safety in the trigger

4.18m Handguns with keyed locking systems

4.19 Grip

4.19a Grips can be various sizes and materials

4.20 Back strap, butt, and front strap

4.20a Ruger firearm showing frame variation. There are many fire-

arms that do not have the traditional back strap, butt, and

front strap. This Ruger double action is noticeably different

form the Smith & Wesson pictured in 4.19. Note also the com-

pressed coiled mainspring that powers the hammer. The grips


on the Ruger totally cover the mainspring and the housing and do not come in contact with the shooter’s hand

4.21 Trigger guard. This trigger guard also acts as a release to open the action

4.21a Trigger guard4.21b Trigger guard4.21c Glock trigger guard with finger rest. This finger rest weakens

the shooter’s grip on the frame and, when used, can interfere

with normal trigger pull

4.22 Spur trigger

4.22a Spur trigger, close-up. Notice checkering on the trigger

4.22b Spur trigger

4.23 Single shot, multiple barrels

4.23a Four barrel Derringer, action open

4.23b It is not uncommon to come across multi barrel guns in both

civil and criminal cases. Notice the white plastic safety strap

installed by this police department to ensure that the gun was

not loaded

4.24 Notice that the firing pin is rotating to four different positions

to align with the four different barrels/chambers

4.24a Alternating firing pin system. On this model, each time the

hammer is pulled back, it alternates between the upper and

lower firing pins

4.24b. Alternating firing pin system; top barrel last fired

4.25 Revolver, double action, with parts labeled

4.26 Chin

4.27 Top strap

4.28 Breach face

4.29 Prawl

4.30 Pressure Plates

4.31. Forcing cone

4.32 Cylinder gap

4.33 Crane

4.34 Cylinder release

4.35 Cylinder

4.36 Extractor or ejector rod

4.37 Extractor or ejector

4.38 Ratchet

4.39 Hand or prawl

4.40 Window

4.41 Chamber(s)

4.42 Flutes

4.43 Lock notches

4.44 Lock or bolt

4.45 Mainspring

4.46 Revolver, single action


4.47 Loading gate4.48 Ejector housing (right side)4.48a Ejector housing (left side)4.48b Ejector housing with parts labeled4.49 Ejector or extractor protruding through chamber4.49a Ejector or extractor, retractable4.50 Axis rod or base pin. The cylinder rotates on the base pin4.50a Axis rod or base pin (close up)4.51 Semiautomatic handgun with parts labeled4.52 Slide. The slide moves back at high speed during the firing

process and has been known to cause injury to the hand when

the hand is in the path of it travel

4.52a Slide multiple views

4.53 Reciprocating bolt. In this Ruger semi-automatic pistol the

bolt moves back and forth surrounded by a tube like frame.

4.54 Slide lock or release. 1911A1 Style

4.55 Ejection port. Springfield Armory 1911A1 variant. When a

cartridge is fired the shell casing may be thrown out with

force and can be very hot

4.55a Ejection port action open

4.55b Ejection port action closed

4.55c Ejection port Taurus “PT101”

4.55d Ejection port Ruger “P94”

4.56 Tang

4.57 Chamber

4.58 Extractors for semi-automatics

4.59 Ejector. Ejectors are often fixed metal pins or bars mated to

the frame. When the rear of the cartridge case impacts the

ejector at high speed, the ejector will knock the cartridge case

out of the grip of the extractor, normally forcing it through the

ejection port

4.59a Ejector close up

4.59b Ejector top view

4.59c Left side view Berreta

4.59d Ejector close up

4.60 Firing pin also used as an ejector in some models

4.61 Magazines, double stack and single stack

4.61a Internal parts of a magazine

4.62 Magazine release bottom (European release)

4.62a Magazine release, close up

4.62b Magazine release

4.62c Magazine release

4.63 De-cocker Ruger “P85” fire position

4.63a De-cocker Ruger “P85” close up safe position

4.63b De-cocker Walther PPKS

4.63c De-cocker ambi-dexterous Taurus “PT101”


4.63d Safety on 1911A1 only acts as safety4.63e Safety has been extended for easier leverage4.64 Magazine well4.65 Revolver, tip up with parts labeled4.65a Rammer unloading procedure4.66 Revolver, top break with parts labeled4.67 Bolt action handgun XP-100 with parts labeled4.67a Original plastic stock to XP-1004.68 Gas operated semiautomatic handgun “Wildey” with parts

labeled4.68a Close up of barrel on gas operated4.68b Gas operated “Wildey” with action locked open and maga-

zine out4.68c Muzzle crown and visible rifling on “Wildey”4.69 Movie of a single action firearm being cocked and dry fired

4.70 Movie of a double action firearm being dry fired

4.71 Double action only firearms. All of these are double action

only handguns

4.71a Iver Johnson top break hammerless

4.71b Smith & Wesson model 640. Hammer is internal to frame

4.71c Smith & Wesson 640 close up

4.71d North American Arms “Guardian” .32 ACP

4.71e Keltec “P11” 9mm. Notice belt clip at rear of slide

4.71f KAHR “E9” 9mm

4.71g Smith & Wesson revolver hammer is protected by side

shields that are part of the frame. Hammer spur can still

cock to single action

4.71h Hammer spur is visible and reachable but with some

difficulty

4.71i Top view of hammer spur

4.71j Hammer spur cut back for double action only

4.72 Swing-out cylinder

4.73 Movie of cartridges being ejected

4.74 Cartridge under the ejector

4.75 Movie of lock or bolt moving down to allow cylinder rotation

and up again to lock cylinder. Internal parts of the hammer

and trigger and their action in both double and single action.

Notice that the hammer does not come back as far in double

action or with as much force in single action

4.76 Loaded or not? The small pin sticking out above the hammer

denotes a cartridge in the chamber. This pin can be difficult

to see in low light situations

4.76a Cocked indicator does not let you know if a round is in the

chamber

4.77 Rim partially exposed when cylinder is closed. As can be

seen, part of the rim of the cartridge cases are visible, but

does not show if the cartridges are empty or loaded


4.78 Recessed chambers often cartridges are not visible when the chambers are loaded

4.78a Recessed chambers partially and fully loaded4.79 Nickeled casings in nickel firearm

4.79a Brass casings in blued cylinder. Too quick a glance and it

could be interpreted as and empty chamber with light shining

through

4.80 Hammer block safety system

4.81 Transfer bar safety system

4.82 Single action trigger. Notice in the bottom right hand corner

the double action revolver is cocked to single action. Very

light and slight trigger pressure is required to fire the fire-

arm. The cylinder has rotated to the correct position and the

only function of the trigger is to release the hammer, which is

under spring tension

4.83 Single action, four positions for the hammer: Top left, rest-

ing on the frame; top right; safety notch off of the firing pin;

bottom left, half cocked (cylinder will spin); bottom right,

cocked, ready to fire position. Not all single actions have

these four positions

4.84 Movie: Cylinder spins when loading gate is open, allowing

for examination of the empty chambers or cartridges in the

chambers

4.85 Movie: Unloading a single action firearm using the ejector

rod

4.86 Magazine forward of trigger guard. There are 3 manufactur-

ers represented for the four different models shown. All are

very similar in design

4.87 Firearm with grip safety

4.88 Springfield safety installed in trigger

4.89 Three different safeties on four different Raven handguns

4.89a Raven P-25 Series 1 Type 1, grooved safety button that slides

horizontally

4.89b Raven MP-25 Series 2 Type 2, grooved tab that slides

horizontally

4.89c Raven MP-25 Series 3 Type 3, safety pivots and locks slide.

The safety must be placed in the “fire” position in order to pull

the slide back to eject the cartridge from the chamber. If the

trigger finger is held along side of the slide, it can be placed in

danger because of the close proximity of the muzzle. While it

is not uncommon for many firearms, such as the Colt 1911 A1

to operate in this manner, extreme caution must be exercised

in the unloading process with this because of its small size

4.89d Phoenix “Raven”. Phoenix Arms Purchased the Raven com-

pany renaming the model. It possesses the same safety hazard

as the Raven MP-25 Series 3 Type 3

83

5 Ammunition

The understanding of ammunition relies more on memorization than on the nomen-clature, because nomenclature is not a reliable means of determining the actual dimensions of any given cartridge. Marketing seems to be the driving force for the names of cartridges. Each and every different cartridge has peculiarities, whether in a historical, marketing, or factual basis. Accepting that reality, we can look at the general features and nomenclature of ammunition, starting with general commonali-ties. Human factors safety concerns are highlighted in bold throughout the chapter.

COMMON FEATURES OF AMMUNITION

All common modern cartridges have four basic components: the case, projectile, powder charge or propellant, and primer.

THE CARTRIDGE CASE

The cartridge case typically is a cylinder closed at one end and acts as the packag-ing that holds the other components in place. Cartridge case bodies can be differ-ent lengths and widths. There are three different body styles: straight, tapered, and bottlenecked (Figure 5.1; DVD 5.1). Straight walled cartridges are the same diameter at the mouth and base of the case. In actuality, many cartridges considered to be straight walled cases have a very slight taper with the base being slightly larger. An example would be the .25 Auto cartridge in which the neck diameter is .001 smaller than the base (DVD 5.2). A tapered case has a larger base than neck. An example would be the .30 Carbine and 9 mm Luger cartridge (DVD 5.3). The bottlenecked body style has a much larger base than neck; this allows for a large powder charge behind a small projectile. Some examples are the 357 SIG, .30 Mauser, and .32 NAA (North American Arms; DVD 5.4).

There are five different cartridge bases: rimmed, rimless, rebated, semirimmed,

and belted (Figure 5.2; DVD 5.5). Any base can have any body style. Rimmed and rim-

less cases are the most common base styles in handguns. Typically, a revolver uses a

rimmed cartridge. On a rimmed case the rim protrudes out significantly from the walls

of the case. The rim holds the cartridge in the correct place in the cylinder of a revolver,

thus keeping the cartridge from sliding into the chamber. Common rimmed cartridges

are the .357 Magnum, .38 Special, .44 Magnum, and .45 Long Colt (DVD 5.6). Most

common semiautomatic handguns will use a rimless cartridge. The rimless cartridge

has a rim that is even with the outside dimensions of the case. The whole cartridge fits

into the single chamber with the breechface supporting the rear of the cartridge. There

is a ring cut into the base that allows the extractor to hook the rear of the cartridge

to facilitate extraction; this is called the extractor groove. Common cartridges found


that are rimless are the .380 ACP, 9 MM Luger, .40 S&W, and .45 AUTO (DVD 5.7). Less commonly found in handguns is the rebated cartridge case. Rebated cartridges have a rim that is less than the diameter of the walls of the case and extractor groove. Examples of the rebated cartridge are the .50 and .41 Action Express (AE) (DVD 5.8). Semirimmed bases have a rim that protrudes slightly out from the body of a case and an extractor groove. An example of a semirimmed is the .32 Auto (DVD 5.9). Belted cases have an extra belt of metal around the base and above the extractor groove. Belted casings are most common to magnum rifle cartridges. Common cartridges would be the 7 MM Magnum and .300 Winchester Magnum (DVD 5.10).

Beyond the shape of the body of the cartridge and different rims, other parts of a cartridge case are as follows (Figure 5.3; DVD 5.11).

Mouth. The opening at the top of the case where the projectile is seated.Neck. The top portion of the case clearly visible on a bottlenecked cartridge

above the shoulder.Shoulder, Cartridge. The sloped portion below the neck on a bottlenecked

cartridge.Extractor Groove. The cut into the body above the rim to aid in extraction.Primer Pocket. The area cut out of the base to allow for insertion of the primer.

Straight Bottle Neck Tapered

Drawn by: Royal Antles, Paul Paradis

FIGURE 5.1. Different body styles of cartridges. From left to right, straight, bottlenecked, and tapered.

RIMMED RIMLESS REBATED BELTEDSEMI_RIMMED

Drawn by: Royal Antles, Paul Paradis

FIGURE 5.2. Different cartridge bottoms. From left to right, rimmed, semi-rimmed, rim-

less, rebated, and belted.

Ammunition 85

Flash Hole. The hole cut through the base that allows the sparks from the primer to reach the gunpowder/ propellant.

Web. The thin metal separating the main chamber of the case from the primer pocket around the flash hole.

Head. The base of the case, including the rim, extractor groove, primer pocket, and web.

Cannelure Cartridge. Rolled groove on the case that supports the projectile from being pushed further into the case by the force of recoil.

Crimp. The pushing in of the case mouth into or against the projectile to hold the projectile firmly in place. There are different types of crimps

used on ammunition.

Case Material. A cartridge case can be made of brass, nickel-plated brass,

aluminum, or steel (DVD 5.13). Often, thecolorof thecasecanblend

into the color of the metal of the firearm, or blend into the appear-

anceofanunloadedchamber,sothataquickglancewouldallowthe

shootertobelievethefirearmwasunloadedwhenitwastrulyloaded

(DVD5.14;5.15).Manyfirearmsdonothaveaneasywaytohelpauser

todeterminewhetherornotacartridge ispresent—especiallywhen

theactionisclosed. When verifying whether or not a firearm is loaded,

attention should be solely focused on both visual and (when possible) physi-

cal verification as to chamber and magazine status. Physical verification is

placing a digit into the chamber to insure that it is empty. Brightly colored

followers in the magazines also aid in detection of loaded–unloaded status

(DVD 5.16). Low light, shadows, and no light situations also pose serious

problems in cartridge recognition. Interruptionsintotalattentiontothis

inspectiontaskcanbedisastrous.

Headstamp. Information stamped into the base of the cartridge that may iden-

tify caliber, manufacturer, factory codes, date of manufacture, or other

PowderCharge

Head

PrimerPrimer Pocket

Web

Rim

FlashHole

Case

Shoulder

Neck

Mouth

Body

ExtractorGroove

Projectile

FIGURE 5.3. Diagram of a typical cartridge.


information about the cartridge (DVD 5.12). Cartridge caliber designations on commercially made ammunition are designed to help the user determine that the correct ammunition is being used in a given firearm. This is known

as the headstamp and is placed on the bottom of the case. Often, as can be

noted on both the headstamp and ammunition boxes, the information can

be in codes, dates, symbols, or foreign languages.Theheadstampisnot

alwaysdecipherableintousableinformation.On most commercial cen-

terfire ammunition, in addition to the cartridge caliber designation, the name

of the manufacturer or the company’s initials is stamped into the base. On

U.S. military ammunition, the name of the factory/armory that produced it

and the year of production constitute the normal headstamp, withnodesig-

nationonthecartridgeitselfastoitscaliber(DVD 5.12; 5.17).

PRIMING SYSTEMS

Many different priming systems have been developed over time, but most are rarely

encountered. Today, ammunition often is referred to by the location of the priming

system—either as centerfire or rimfire.

Rimfire

When the primer is in the rim, the firing pin must strike the rim to cause ignition.

Common rimfire cartridges are .17 Hornady Magnum Rimfire (HMR), 22 Short (S),

.22 Long (L), .22 Long Rifle (LR), and .22 Winchester Magnum (DVD 5.18). The

.22 Long Rifle is the most popular cartridge made today, being very inexpensive,

accurate, and with little recoil, and little muzzle side blast (DVD 5.19). The rim at

the base of the cartridge is hollow and contains a pressure-sensitive explosive. The

cartridge is placed into the chamber with the top of the rim being placed against, and

supported by, the metal around the chamber. The base of the cartridge is supported

by the breech face or breechblock. When the firing pin hits the rim it crushes the rim,

causing the priming compound to explode and sending sparks into the gunpowder,

which in turn burns almost instantaneously, creating substantial amounts of gas that

propels the projectile from the firearm.

Centerfire Systems

Two centerfire priming systems, the Boxer and Berdan, have remained popular for

almost 150 years. Both are located in the center rear of the cartridge, in the base.

Berdan system. The Berdan system was developed in the late 1850s by Hiram

Berdan, an American colonel, and became the standard ignition system

outside of the United States (DVD 5.20). This system uses a metal cup with

priming compound inside and placed in the primer pocket. At the bottom

center of the primer pocket is a small protrusion of the case that fits inside

the primer cup. When the cup is crushed by the firing pin the protrusion

puts pressure on the priming compound, creating an explosion that ignites

Ammunition 87

the gunpowder. The Berdan system, having multiple flash holes off center in the cartridge, is hard to reload.

Boxer system. In 1858, a British colonel, Edward Boxer, patented a different centerfire system (NRA, 1989b; DVD 5.20 a–5.20e). The primer is a self-

contained unit: a cup with priming compound, foil or lacquer to keep it in

place, and an anvil (that looks like an upside down boat propeller) seated

on top of the priming compound. The anvil, supported by web, provides the

resistance to the firing pin strike, thus causing the priming compound to

explode. A case with one hole in the center can have the old primer removed

quickly by a rod with a pin protruding from it. Early travelers could reload

their cartridge cases with simple tools relatively easily and inexpensively.

As the case is the most expensive part of any complete cartridge, this easy

reloading was a major advantage.

A rimfire and two centerfire priming systems are shown in Figure 5.4 and DVD 5.21.

Both systems work equally as well and are still used today. Currently in the United

States, only Federal Ammunition is commercially making ammunition in quantity

using the Berdan system. Its Berdan system ammunition is sold under the Blaser

brand (DVD 5.22). However, large quantities of ammunition using the Berdan sys-

tem are being imported into the United States.

PROPELLANT

The propellant or gunpowder is the part of the cartridge that actually propels the bul-

let or projectile. Currently, modern smokeless gunpowders are predominately used

rather than the older, more explosive black powder. The current smokeless gunpow-

der is a combustible material that, when ignited, produces tremendous gas pressure

inside the cartridge case. The name smokeless powder is a misnomer in that it is

neither smokeless nor a powder. When smokeless gunpowder is ignited by the sparks

from a primer, it produces less smoke than black powder. Modern smokeless pow-

ders can be in plate, disc, ball, flattened ball, cylinder, or many other shapes, and in a

Boxer Berdan

Rimfire

FIGURE 5.4. A rimfire and two centerfire priming systems, Boxer and Berdan.


number of sizes. There are numerous types of smokeless gunpowders on the market today. In commercially loaded cartridges, manufacturers do not provide the type and quantity of gunpowder as it is considered proprietary information. Onecannot

determinebylookingatacartridgewhattypeofgunpowderisinside. To forensic firearm examiners, it becomes important in their forensic investigations to know the

type of gunpowder, as gun shot residues can determine the distance from which the

shot was fired. For the shooter, changing from one brand of ammunition to another

may mean a different type of gunpowder, which, in turn, can mean a difference in

the trajectory or power of the projectile. Tests of firearms for determining specific

facts should be done with the same ammunition using the same gunpowder. It is

known that manufacturers change gunpowders from time to time. Unfortunately,

manytypesofgunpowderlookthesamevisuallybuthavedifferentformulas

thatallowthemtoburninradicallydifferentways (DVD 5.23).

Both current smokeless gunpowder and projectiles are weighed by a unit of mea-

surement called grains. There are 7,000 grains to an avoirdupois (U.S.) pound, or

437.5 grains to an ounce. Typically, on commercial boxes of ammunition, the only

information provided is the approximate or average weight of the projectile. Noinfor-

mationisprovidedaboutthetypeoramountofgunpowderused(DVD 5.24).

It should be noted that gunpowder currently is classified as a flammable rather

than as an explosive. The process of combustion inside the cartridge is referred to as

deflagration. As the powder burns, it produces heat and pressure in a more controlled

and even manner than detonation, which is more violent and instantaneous; however,

smokeless gunpowders have been known to be used in improvised explosive devices.

As we noted in Chapter 4, failuretohavethecorrectamountofgunpowdercan

havecatastrophicresults(DVD 5.25). If there is not enough gunpowder, the bul-

let can lodge in the barrel, creating an obstruction. Ifanothershotisfiredwitha

bulletlodgedinthebarrel,thebarrelcanburst,creatinginjuries. If there is too

much gunpowder, the pressures can exceed the ability of the firearm to contain it.

Thisturnsafirearmfromahandgunintoahandgrenade.Generally speaking,

modern manufacturing procedures create ammunition that is relatively safe and reli-

able. As was noted in Chapter 4,reloadedammunition(i.e.,ammunitionthathas

hadanewprimer,powdercharge,andprojectileplacedintothefiredcase)has

beenresponsibleformanycatastrophicfailuresandshouldbeapproachedwith

considerablecaution.

PROJECTILE OR BULLET

The last part of the cartridge is the projectile or bullet. The projectile is the part of a

cartridge that actually does the work (Figure 5.5; DVD 5.26).

Caliber

The caliber is a nominal dimension, being approximately the diameter of the pro-

jectile. The original definition was the diameter of the inside of a tube, which with

rifling would be the bore, land to land (i.e., distance of the highpoints left in the

barrel after cutting the rifling). On some cartridges, the assigned caliber designation

number is the diameter, groove to groove. Caliber can be measured in millimeters or

Ammunition 89

inches. A quick rough conversion would be to multiply millimeters by four and that would be the approximate inch caliber. To determine the approximate millimeter caliber from the inch caliber, you divide the inch caliber by four. For example, if you multiply 10 mm by four, the inch caliber will be .40 caliber. In reality the 10 mm Automatic and .40 Smith & Wesson cartridges shoot the same diameter projectile, .400. The difference in the two cartridges is the length of the cases: The .40 Smith &Wesson is .85 inches long, and the 10 mm Automatic is .99 inches long (DVD 5.27). (Barnes, 2003, Cartridges of the World 10th ed. p. 322. Note: Cartridges of

the World is an excellent quick reference for many different common, uncommon, and obsolete types of ammunition. This reference is an important starting point for any investigation into a shooting event. It is a primary reference for forensic labo-ratories. It is found in most crime labs in this country and throughout the world). The extra case capacity of the 10 mm Automatic makes it a more powerful cartridge although the number 10 designation is a smaller number than the larger number 40 in the .40 Smith & Wesson. The primer used in the 10 mm is normally a large pistol primer and the one in the .40 cal is a small pistol primer.

Another example to add to the name confusion is the 9 mm Luger: Multiply by four and the caliber is approximately .36 inches; in reality the standard projectile diameter is .355 inches. The .38 Smith & Wesson Special, commonly referred to as the .38 Special, when divided by four is 9.5 (mm.); in reality the standard bullet diameter is .357 inches. The .38 nomenclature came from the diameter of the loaded cartridge case, outside case wall to outside case wall, most likely from the market-ing ploy of making it seem larger and more powerful then the .36-caliber round ball used in earlier percussion pistols. Both the 9 mm Luger and .38 special shoot projec-tiles approximately the same diameter. The name Luger is from the designer of the cartridge; the name Special was a marketing term that has no significant meaning

today. Neither the 9 mm Luger nor .38 Special, both very common ammunitions

worldwide, has a name that truly defines the dimension of the projectile or what each

is used for.

CannelureHead

Height Jacket

Heel

Base

BearingSurface

Diagram of Projectile

ShoulderOgiveCore

(Internal)

Point(Exposed Lead)

Meplet

Note: Core is typically alead mass located beneath

the jacket

FIGURE 5.5. Diagram of a projectile.


In summary, the caliber labeling of ammunition is very confusing. In the interest of safety, the ammunition manufacturers should develop and use a clear, standard-ized system for labeling ammunition (e.g., an International Standards Organization [ISO] Standard). Such a system could avoid many accidents and injuries from per-sons mistakenly using the wrong ammunition in a particular handgun.

PROJECTILE FEATURES

The specific features of each projectile are as follows.

Base. The bottom portion of the bullet may be enclosed by a jacket, or open,

exposing the lead core.

Bearing Surface. The walls of the projectile that, when fired, contact the fire-

arm’s rifling.

Cannelure Projectile. Either a smooth or serrated groove may be cut around

the projectile for holding lubrication or to allow the mouth of the case to be

crimped tightly to the projectile.

Core. The internal portion of the projectile, normally made of lead.

Jacket. The hard metal covering over the core. Common jacket metals are cop-

per, brass, steel, or aluminum.

Heel. The base portion of the bullet behind the bearing surface; it may be cyl-

inder shaped (square or flat base) or boattail (taper heel).

Meplat. The diameter of the blunt end of the tip of the bullet.

Ogive. All of the bullet forward of the bearing surface; it may be curved,

rounded, or pointed.

Shoulder, Bullet. The point at which the rifling engraving ends and the curve

of the ogive begins.

PROJECTILE SUBGROUPS

Projectiles can be broken into different subgroups; lead, full metal jacket, partially

or semijacketed (designed to expand), and novelty. There also are cartridges with no

projectile, which are known as blank (Figure 5.6; DVD 5.28).

Lead. Lead (DVD 5.29) is a common inexpensive metal that can be easily cast

into projectiles. Lead projectiles are usually hardened by the addition of antimony

and tin, as pure lead melts at a low temperature, which easily is obtained during the

friction created by the projectile traveling through the barrel and from the heat of

the burning gunpowder.

Residues left in the barrel can affect both accuracy and reliability of the firearm.

Although lead is a major source of fouling, molten metals from the case and jacket,

carbon, and unburned and partially burned powder also will cause fouling.

Solid lead (alloyed) bullets are in common use in handgun ammunition today

and are likely to be in the future, regardless of the potential for heavy metal (lead)

poisoning. There are three common shapes to lead bullets: round nose (DVD 5.30),

semiwadcutter (DVD 5.31), and wadcutter (DVD 5.32). Because of both the clean

holes they produce for scoring purposes and excellent accuracy, wadcutter projec-

tiles are mostly used for competitive target shooting. Given their low cost and round

Ammunition 91

nose, semiwadcutter projectiles are used extensively both in competition and infor-mal shooting.

Full metal jacket. These projectiles commonly are formed by inserting a lead core into a preformed hard metal jacket. This style has an exposed lead base, but the nose and all but the base are enclosed by the harder jacket metal (DVD 5.33). A variation of the FMJ is the total metal jacket (TMJ; DVD 5.34), which is fully plated including the base. The jacket allows the projectile to travel faster and with a flatter trajectory than lead bullets, and with less barrel fouling and only a slightly greater cost than lead bullets. Typically, the FMJ projectile has better penetration than lead projectiles. Common use is target shooting and military applications as required by international conventions.

Semijacket (expanding). The partially or semijacket projectiles are typically designed to provide controlled expansion. Two common types of semijacketed projec-tiles are the hollow point and soft point (DVD 5.35). There are many different designs and each requires research to fully understand. The basic philosophy of expanding bullets is (a) to create more tissue damage by the projectile expanding to more than double its original diameter, and (b) to slow the bullet down after impact by creating more resistance via the increased surface area, the intention being to expend more energy into the target. Both hunting and self-defense are applicable uses for expand-ing projectiles, as they can create more tissue damage. Because of their increased manufacturing cost, expanding bullets can cost double what FMJ projectiles cost. Semijacketed projectiles typically are safer to use in an urban environment because they start to expand upon hitting an object, thus losing energy faster and penetrating less than the FMJ projectiles.Accordingly,theyarelesslikelytogothroughthe

Full MetalJacket

Flat Point

RoundNose Lead

Semi-JacketedSoft Point

JacketedHollow Point Novelty

Blank

Projectile Sub-groups

From Left to Right: Fiochhi “CAL 450 CORTO” balle de plomb (lead bullet) 226 gr.,Winchester 40 S & W 180 GR. Full Metal Jacket (Flat Point), Winchester Black Talon 40 S & W 180 GR. SXT,

PMC 357 Magnum 158 GR. Jacketed Soft Point, Corbon Pow’RBall (White Polymer Ball Cap),MRA Full Plastic Cased Blank

FIGURE 5.6. Projectile subgroups. From left to right, lead, full metal jacket, partially or semijacketed (hollow point and soft point), novelty, and a blank.


intendedtargetandhitsomeoneelse. Often, the term dum-dum is improperly used to describe expanding bullets, as it has a negative context (DVD 5.36).

Novelty. Novelty projectiles are nontypical projectiles that expand in nontradi-tional ways. One example is the Hoxie bullet manufactured c. 1907 that had a steel ball placed in the soft exposed lead of the nose to supposedly expand the projec-tile better upon impact. Most novelty bullets for handguns have been substantially more expensive than standard expanding projectiles and often underperform stan-dard expanding projectiles. One tested by Paul Paradis was found to offer some protection from overpenetration: the Glaser Safety Slug (DVD 5.37). The Glaser projectile is a copper cup filled with small lead shot pressed into a core with a Tef-

lon tip. In apartments that often had only two layers of sheetrock separating family

living quarters, the Glaser projectiles would impact, creating what is probably best

described as a mechanical expansion, bursting the projectile into small, preformed

fragments that lose energy quickly because of their small size and weight. Direct

impacts appear to have the potential for great tissue damage, but far less penetration

and distance if they impact an intervening object then standard style projectiles,

discussed previously.

Blanks. Another type of ammunition that receives publicity only when a death

occurs (e.g., on Hollywood movie sets) is blank ammunition. Blanks are cartridges

that have no projectile but often have wadding holding the gunpowder in place.

When the blank is fired, the wadding is thrown out with tremendous force for very

short distances (DVD 5.38). Blanks are relatively common and often used in military

maneuvers, theater, street shows, and high school and college student plays. Often,

thedangerinblanksisnotevident,astheytendtobethoughtofasmake-believe

ammunition.Therealityisthatmanyblankshavealargepowderchargeand

are capped with cardboard or plastic wadding to keep the powder in place.

Whendischargedinafirearm,thereisatremendousamountofgasproduced

andmuzzlecontactwiththeheadcanbefatal.Atdistances,injuriescanoccur

notablytotheeyes(Di Maio, 1985).

CARTRIDGE DESIGNATIONS AND OTHER CONFUSING FEATURES

CARTRIDGE DESIGNATIONS

Cartridge designation on loaded ammunition is stamped into the base of the case on

most commercially available ammunition. But with the global trade that is common

today, surplusmilitaryammunitioncommonlyisavailablethatprovideslittleif

anyinformationastowhatisthecorrectdesignation. Itisrelativelycommonto

findboxesofammunitioninwhichthecartridgeinformationisinaforeignlan-

guage,undecipherabletotheaverageconsumer. A case in point, seen by author

Paul Paradis, was what appeared to be 9 mm Luger ammunition that had Arabic

writing on the box and headstamp (DVD 5.39). The unhappy owner of a 9 mm Luger

handgun that had burst in his hand had asked for help in determining what had

happened. In researching the ammunition and having the Arabic interpreted into

English, it was found that there was a warning for submachine guns only. The owner

had come across what he thought was a good 9 mm ammunition bargain. In reality,

Ammunition 93

the ammunition was loaded with too high a pressure for normal handguns. The great deal on the ammunition was not such a great deal after all. The savings were approx-imately $2.00 per box when compared to commercially available ammunition.

INTERCHANGEABILITY AND NONINTERCHANGEABILITY OF CARTRIDGES

Manycartridges startwith the samenumeraldesignationbutarenot safely

interchangeable. A common example is the 9 mm designation. The 9 mm Luger (named after the designer Georg Luger) cartridge has many different names for the same cartridge; 9 mm (named after caliber designation), 9x19 (named after cali-ber designation and length of case), 9 mm Parabellum (name taken from the Latin phrase, “If you want peace prepare for war”), 9 mm NATO (name from NATO forces that adopted it as a standard cartridge), and 9 mm P08 (named after the pistol model number it is used in), to name just a few. But there are many other cartridges that start with the 9 mm designation that are improper and potentially dangerous to inter-change. Examples are 9 mm Corto, 9 mm Makarov, 9 mm Kurz, 9 mm Ultra, 9 mm Browning Long, 9 mm Steyr, 9x23 Winchester, 9 mm Glisenti, 9 mm Bayard, 9 mm Federal, 9 mm Mauser and many, many others that may sound somewhat similar to the 9 mm Luger but can be dramatically different in pressures developed.

Table 5.1 shows common cartridges and other names by which they are known.Some firearms can shoot more than one style of cartridge. A general rule to go

by is that they must be rimmed cartridges with all dimensions the same except for the

length of the cartridge. For example the .357 Magnums also can shoot the .38 Special

TABLE 5.1.

List of common cartridges and some other names by which they are known.

Cartridge Also known as

.25 ACP 6.35 Auto; 6.35 Browning; .25 Cap; .25 Auto

(CD 540)

.32 ACP 7.65mm; 7.65 Browning; .32 Auto; .32 CAP;

7.65 Auto

7.65 Luger 7.65 Parabellum; .30 Luger; 7.65x21mm

(CD5.41)

.30 Mauser 7.63 Mauser; 7.63x25mm

380 ACP .380 Auto; 380 Automatic; 9mm Kurz; 9x17mm;

9mm Corto, 9mm Court, 9mm Kratak, 9mm

Browning Short, 9mm Scurt

9mm Makarov 9x18mm; 9mm Mak

9mm Luger 9mm, 9mm Para, 9mm Parabellum; 9x19mm,

9mm NATO

.38 Special 9x29R, .38 Spl, .38 Smith &Wesson Special

.38-.40 .38 WCF; .38 Winchester

.44-.40 .44WCF; .44 Winchester

.45 Schofield .45 S&W

.45 ACP .45 Auto; .45 Automatic, 11.43x23mm


+P and the .38 Special used in revolvers, as well as other rounds that are shorter and less powerful. The .357 Magnum cartridge has a case length of approximately 1.29 inches and has a working pressure of approximately 35,000 psi. The .38 Special has a case length of approximately 1.16 inches and average working pressure of 15,000 to 17,000 psi. The .38 Special +P has average working pressure of approx 18,500 psi but is identical in dimensions to the .38 Special. The symbols +P and +P+ denote car-tridges loaded to higher pressures. Due to the rim holding the cartridge in the correct position in the chamber, the .38 Special and the .38 Special +P can be fired safely in

the .357 Magnum (DVD 5.42). Theinverseisnottrue;the.38Special+P,even

thoughithastheexactsamephysicaldimensionsasthe.38Special,hasmore

pressure,andmanyhandgunsdesigned for the .38Special cartridgewillnot

holduptothehigherpressuresofthe+Ploads—sometimeswithcatastrophic

results. Contacting the manufacturer, the owner’s manual when available, or a quali-

fied gunsmith would be appropriate to insure the firearm/ammunition combination is

safe. Althoughitusuallyissafetointerchangesomeammunitionsinrevolvers,

inotherfirearms,suchassemiautomatics,jammingwilloccurbecauseofinsuf-

ficientpressuresbeingdeveloped.

A chart of cartridges that are commonly interchangeable is depicted in Table 5.2.

This is not an all-inclusive list. The order is in descending pressures.

LOADING DEVICES

Another source of confusion can be loading devices that alter the shape of a

cartridgetoworkinadifferentmechanism. An example of this is the Colt New

Service Model 1917 and Smith & Wesson Hand Ejector Model 1917 revolvers, manu-

factured during WW1. A device known as a moon clip (Figure 5.7; DVD 5.43) was

attached to the .45 Auto cartridge at the extractor groove to allow for use in a revolver.

This facilitated the use of one cartridge for multiple action firearms, revolvers, and

semiautomatics. The .45 Auto Rim (AR) cartridge was later developed to do away

with the moon clips. Although the .45 AR cartridge is no longer being manufactured,

revolvers are using moon clips in different calibers to facilitate fast reloading for both

competition and self-defense. Other devices, known as speed loaders or quick loaders

(DVD 5.44), also are commonly available for reloading revolvers quickly.

TYPES OF MALFUNCTIONS

All ammunition is subject to malfunctions, the most common being the following.

Misfire. A failure for the cartridge to work at all. When the trigger is pulled

on a properly working firearm, nothing happens. The primer may, or may

not, be damaged.

Hang fire. A perceptible delay in the ignition process. When the trigger is

pulled there is a felt moment of time in which nothing happens, then the

cartridge fires. This can be a dangerous situation unless the firearm is kept

pointed in a safe direction, usually 30 seconds. Oftenshootersperceivea

misfire,starttorelaxandreload,andthecartridgefires.

Ammunition 95

Full moon ClipsHalf moon

Clips

FIGURE 5.7. Moon-clip loading devices ( full moon and half moon).

TABLE 5.2.

Ammunition interchangeability chart:

Ammunition for which the gun is designed Ammunition which also can be used safely (See note at bottom of the chart)

Rimfire Cartridges

.22 BB Cap .22 CB Cap

.22 Short .22 BB Cap

.22 Long .22 Short

.22 Long Rifle .22 Long

.32 Long .32 Short

Centerfire Cartridges

.32 Smith & Wesson Long .32 Smith & Wesson

.32 Long Colt .32 Short Colt

.38 Special (Spl) .38 Long Colt

.38 Spl +P .38 Spl

.38 Spl +P+ .38 Spl +P

.357 Magnum (Mag) .38 Spl +P+

.357 Maximum (Max) .357 Mag

.38 Super Auto .38 Colt Auto

.44 Smith & Wesson Special .44 Smith & Wesson Russian

.44 Remington Magnum (Rem Mag) .44 Smith & Wesson Special

.45 ACP .45 Auto Rim (AR) (Revolvers only)

.45 Long Colt (LC) .45 Schofield

.454 Casull .45 LC

.460 S&W Magnum .454 Casull

Note: Ammunition of less power may not function correctly in some firearms (usually semiautomatics)

and may cause malfunctions due to less than needed pressures developed. An example would be a

.357 Magnum semi-automatic pistol shooting a .38 Short Colt cartridge is safe, but may not func-

tion (eject / extract the cartridge case) resulting in a jam. Caution should also be taken to insure that

the forward edge of the chamber be kept clean after using the shorter cartridges so that the longer

cartridge is not inhibited from fully entering the chamber.


Squib load. Insufficient pressure developed by the cartridge to dispel the pro-

jectile. Often there is little felt recoil and a pop sound rather than the normal

bang heard. Ifthebulletlodgesinthebarrel,itcreatesanobstruction

thatcancauserapidandspontaneousdisassemblyofthefirearminthe

shooter’shand. Paul Paradis has personally seen this happen on numerous

occasions. Normally, on lower-pressure handgun ammunition, the barrel

only bulges into an egg shape. But occasionally the firearm bursts with

vigor, injuring those in close proximity. Amazingly, often the shooter has

little to no injuries while close bystanders received more significant inju-

ries. The trigger guard and bottom of the frame appeared to act as a shield

and the explosion went out and away from the shooter—mostly to the sides

of the firearm.

OTHER DANGERS WITH AMMUNITION

INTERMINGLING AMMUNITION TYPES

Often,shootersblamethefirearmorammunitionforhazardscreatedbythem-

selves. A common example is the intermingling of multiple ammunition types. This

is particularly likely to happen if the shooter is in a hurry, or his or her attention is

directed elsewhere, and thus appropriate devotion to insuring that the correct ammu-

nition is being used in the shooter’s firearm is diminished.

INCORRECTLY LOADED CARTRIDGES

A word of caution about the potential for incorrectly loaded cartridges. Reloading is

a common pastime amongst many shooters (i.e., they take an empty, usually prefired

cartridge case and remanufacture a loaded cartridge). This is done using specialized

reloading equipment to remove the fired primer and replace it with a new primer.

Then a powder charge is measured out, either by weight or volume, and placed into

the newly primed cartridge case. Last, a new projectile is placed into the case and

crimped into position. Some reloaders take great care in making their reloaded

ammunition, and some do not. Manyhigh-qualityfirearmshavebeendestroyed

bythosethatdonot,ofteninjuringthemselvesandothers.

When investigating firearm mishaps it is important to collect any ammunition

left, as well as the fired casings, to determine if the problem was an incorrect powder

charge or other incorrect procedures. Quite often, it is difficult to determine when

a cartridge has been reloaded. Typically, forensic firearm examiners are usually the

most reputable source for determining whether cartridges have been reloaded or not

(DVD 5.45).

LOADING A HANDGUN WITH THE WRONG AMMUNITION: WARNING SIGNS

A warning sign for potential mistakes in loading a firearm with the wrong ammuni-

tion is a fired cartridge case that is misshapen, cracked, or bulged when examined

after firing. The cartridge case, because of the pressures created internally during the

firing process, will stretch in length and expand the case dimensions. If the chamber

Ammunition 97

of the firearm is damaged, worn out, or incorrect for the cartridge used, damage

to the fired casing can be obvious. It is important to note that this could be due to

mechanical failure as well as ammunition failure. A properly trained gunsmith can

usually make the proper determination. Many examples of damaged casings have

been seen by the authors on firearms that were not sufficiently marked as to the cor-

rect ammunition to be used. The procedure used by most gunsmiths to check for the

correct ammunition to be used is to cast the chamber (DVD 5.46).

DUMMY CARTRIDGES AND THEIR UNIQUE DANGER

In order to remain proficient, many shooters practice dryfire drills. That is, they

practice with an unloaded firearm. Often, dummy cartridges are used to protect the

firearm’s action. Dummy cartridges also are used to enable the firearm handler to

safely practice clearing a malfunction. The cartridges used for this type of practice

are referred to as dummy cartridges. Dummies are cartridges that have no powder

charges or primers (Figure 5.8; DVD 5.47).

Unfortunately, these safety devices are another source of injury in a unique man-

ner. Instructors, and other shooters, sometimes make dummies by reloading fired cas-

ings and using the spent (fired) primer to cushion the firing pin when it slams forward.

This has been done because dummies were not readily available in the needed caliber

or simply to save money. Often, it is impossible to tell oneof these instructor-

madedummiesfromacartridgethathadtheunfiredprimerimpactedandnot

setoff(misfired; DVD 5.48). When one of these misfired cartridges is mistaken for

a dummy and is placed in a gun, the additional force needed to fire the misfired car-

tridge is applied—usually to the great surprise of the gun handler. Thissituationhas

beenresponsibleformanydeathsandinjuries.For example, one of these caused

the death of a police officer in a major metropolitan city. Because of these deaths, to

prevent persons from having to make their own dummies from fired casings, many

commercial companies now produce cartridge dummies in many different calibers.

To aid in discriminating dummies from live ammunition, some companies make

dummies using colors not typically seen in normal loaded ammunition. Aswithall

otherammunition,itusuallyisnoteasy,orsometimesevenpossible,toseewhat

isinthefirearm—onealwaysneedstocheckforitphysically.

FIGURE 5.8. Commercially made dummy cartridges.


Arelatedproblem thatcanresult in injuryordeath is the failureof the

firearmhandlertorememberifsheorhehasputliveammunitionbackintothe

firearm. This usually happens while being interrupted during practice. Often, shoot-ers trade out the dummies with live rounds, finish their practice, and then decide to

perform some drill one more time. Following the formal practice session, it is criti-

cal for the shooter to clearly change his or her mindset from training to being back

in the real world—to consciously end the training session. A well-known story told

in many law enforcement training courses is one of a senior officer working with a

younger officer who was having trouble drawing his handgun from his holster and

shooting from the hip as part of a standard two-second drill, known as point shoot-

ing. The senior officer would give a trigger word command for the younger officer to

draw his gun, and aim and fire at the senior officer. After numerous trials, the train-

ing session ended. The senior officer was unaware that the junior officer then loaded

his gun with live ammunition. As the junior officer was getting ready to leave, the

senior officer again gave the trigger word command. The junior officer immediately

drew his gun, pointed it the senior officer and shot, killing him. Understandably, the

junior officer, not having made a clear change in mindset (i.e., that the training ses-

sion was over and he was now back in his real-world situation as a police officer with

a loaded weapon), made a conditioned response.

HUMAN FACTORS ISSUES RELATED TO AMMUNITION

Throughout this chapter, a number of human factors safety issues have been noted.

Most of these fall into two classic human factors safety deficiency categories: confu-

sion resulting from a lack of standardization (of ammunition labeling, in this case),

and lack of discriminability (of various types of ammunition).

CONFUSION RESULTING FROM LACK OF STANDARDIZATION

OF AMMUNITION LABELING

Headstamp Labeling. As noted early in this chapter, the headstamp is not always

decipherable into usable information.On most commercial centerfire ammunition,

in addition to the cartridge caliber designation, the name of the manufacturer or

the company’s initials are stamped into the base. On U.S. military ammunition, the

name of the factory/armory that produced it and the year of production constitute the

normal headstamp, with no designation on the cartridge itself as to its caliber. It is

relatively common to find boxes of ammunition in which the cartridge information

is in a foreign language, undecipherable to the average consumer.

Caliber Designations. To begin, the caliber designations on ammunition can be

stated either in millimeters or inches, which can be confusing in and of itself. Many

cartridges start with the same numeral designation but are not safely interchange-

able. A common example, noted earlier, is the 9 mm designation. The 9 mm Luger

cartridge has many different names for the same cartridge; 9 mm (named after cali-

ber designation), 9x19 (named after caliber designation and length of case), 9 mm

Parabellum (named taken from Latin phrase “If you want peace prepare for war”),

9 mm NATO (name from NATO forces that adopted it as a standard cartridge), and

Ammunition 99

the 9 mmP08 (named after pistol model number used in), to name just a few. There are many other cartridges that start with the 9 mm designation that are improper and potentially dangerous, as they can be dramatically different in pressures developed. This is not only the case with 9 mm designations but with those for many other des-ignations as well. The chart of the different names used for a number of common cartridges, shown earlier in this chapter, illustrates just how tremendously confusing the designations are on ammunition.

DISCRIMIMINABILITY ISSUES

There are several serious ammunition issues relating to inadequate means of dis-crimination, which potentially can result in injury or death. The more important of these are as follows.

Different (Unsafe) Ammunition Fitting Into a Given Handgun. Related to the issue of highly complex and confusing ammunition designations, noted earlier, dif-ferent types of ammunition often can fit a given handgun. Although they may fit,

differences, such as in the amount of gunpowder, render some seemingly identical

cartridges not truly interchangeable and can cause the gun to explode upon firing.

Development of a standardized method of designating the various critical character-

istics of ammunition, such as size, power, and so on, could go a long way to prevent-

ing use of the wrong ammunition in a given handgun. This is a classic type of issue

that has been successfully addressed by human factors professionals in many other

product areas.

Propellant. In commercially loaded cartridges, manufacturers do not provide

the type and quantity of gunpowder because it is considered proprietary information.

One cannot determine by looking at a cartridge what type of gunpowder is inside.

Unfortunately, many types of gunpowder look the same visually but have differ-

ent formulas that allow them to burn radically different. For the shooter, changing

from one brand of ammunition to another may mean a different type of gunpowder,

which, in turn, can mean a difference in the trajectory or power of the projectile.

Dummies Versus Misfired Cartridges. Often, it is impossible to tell a dummy,

made by reloading fired casings and using the spent (fired) primer to cushion the

firing pin, from a cartridge that had the unfired primer impacted and not set off

(misfired). When one of these misfired cartridges is mistaken for a dummy and is

placed in a gun, the additional force needed to fire the misfired cartridge is applied

and the gun discharges. Numerous injuries and deaths have resulted. Put simply, any

dummy cartridge, including those made from spent cartridges, needs to be clearly

distinguishable as a dummy.

Blanks. The discriminability issue here is mistaking, or thinking of, blanks as

make-believe ammunition. Often, the danger in blanks is not evident. As noted ear-

lier, many blanks have a large powder charge. When discharged in a firearm, there

is a tremendous amount of gas produced, and muzzle contact with the head can

be fatal. Injuries also can occur at distances, most notably to the eyes. The dan-

gers associated with using blanks need to be clearly indicated on the boxes of blank

ammunition (DVD 5.49).



DVD # Description

5.1 Different body styles of cartridges. From left to right, straight, bottlenecked, and tapered.

5.2 Winchester 25 Auto (ACP), 50-grain full metal jacket (FMJ) projectiles: Common caliber ammunition typically used in small pocket/concealable semiautomatics and derringers.

5.3 Tapered case cartridges, 30 carbine and 9mm: Many car-tridges like the 30 carbine and 9 mm can be used in revolvers, semiautomatics, and rifles.

5.3a 9 mm and 30 carbine with scale 5.3b 9mm with scale5.3c 30 carbine with scale5.4 Bottle neck cartridges—left to right: 357 SIG, 30 Mouser

(7.63mm), and 32 NAA.5.4a Bottleneck cartridges with scale—same order as above. 5.5 Different cartridge bottoms. From left to right, rimmed, rim-

less rebated, semi rimmed, and belted. 5.6 Straight walled cartridges, left to right, 357 MAG, 38 Special,

44 MAG., and 45 Long Colt (LC), with scale.5.6a 357 Magnum with scale5.6b .38 Special with scale5.6c .44 Magnum with scale5.6d .45 Long Colt with scale5.7 Rimless cartridges, left to right – 380 ACP, 9 mm Louger; 40

S&W; 45 Auto.5.7a 380 ACP with scale5.7b .40 S&W with scale5.7c .45 Auto with scale5.8 Rebated rims—50 and 41 Action Express (AE): While not

unique, rebated rims are less commonly found than the more popular rimless bases.

5.8a .50 Action Express with scale5.8b .41 Action Express with scale5.9 Semi rimmed .32 auto (ACP}: Notice also that the nose of the

bullet has been precut to allow for better expansion.5.10 Belted 7 mm and 300 Win Mag5.10a Close-up of belted portion of cartridges5.11 Diagram of a typical cartridge5.12 Head stamp: WIN (Winchester) 9mm LUGER [Silver portion

in the center is the ignition system (primer)].5.13 Different common casing materials – left to right: steel, brass,

aluminum, and nickel-plated brass.

Ammunition 101

5.14 Nickel case in stainless gun.5.15 Dark ammunition in chamber: Note that you can hardly see

the cartridge and, thus, could mistakenly think the chamber is empty. Not only does the color of the ammunition pose a visual problem, but also shadows can have the same effect, even on more brightly colored ammunition.

5.15a Dark ammunition in magazine.5.16 A stainless follower5.16a Orange follower5.17 A coded military round WCC 82 (Winchester Cartridge

Corp., 1982 manufacture)5.17a R (Remington .22 long rifle rim fire). Notice that there is no

ignition system. (primer), which is one indicator of it being a

rimfire cartridge case.

5.17b F (Federal .22 long rifle rim fire)

5.17c X with the word “SUPER” imposed upon it (Winchester .22

long rifle rim fire).

5.17d HORNADY .45 AUTO +P (brass primer)

5.17e Russian “JUNIOR” (.22 LR)

5.17f FC 98 45 AUTO (Federal Cartridge, 1998 manufacture).

5.17g R-P 45 Auto (Remington Peters centerfire)

5.17h FEDERAL 45 AUTO (centerfire, nickel primer, brass car-

tridge case)

5.17i 44 dnh St+ 9 (dnh is the WWII German factory Bohmische

Waffenfabrik, Strkonitz plant, Prague, 1944)

5.17j S&B 9mm M (9mm MAKROV, Seller & Bellot centerfire)

5.17k ARABIC headstamp on 9mm Luger ammunition (notice pur-

ple sealant around primer – a form of weatherproofing).

5.17l Russian made 7.62 NAGANT in original box.

5.17m Close-up of headstamps from 14l: 38 72 (Russian factory

codes).

5.17n CCI BLAZER ammunition in box.

5.17o Close-up of 514.n: CCI 9mm LUGER.

5.17p INDEPENDENCE ammunition in box.

5.17q INDEPENDENCE ammunition headstamp from 5.14p: *I*

38 SPL (Special).

5.17r 45 AUTO CBC Brazilian headstamp on ammunition imported

by MAGTECH.

5.17s CCI NR 10mm AUTO (NR = non-reloadable; notice the alu-

minum cartridge case)

5.17t F (FEDERAL ammunition marketed by Sears)

5.17u CORBON ammunition in box.

5.17v Headstamp from 5.14u: COR-BON 40. S&W

5.17w CORBON AUTOMAG ammunition with scale

5.17x *-* 44 AUTO MAG. (CORBON Ammunition with differ-

ent headstamp from box in photo 5.14w. It is not uncommon


for one manufacturer to purchase components from another manufacturer.

5.17y GECO 6.35mm (aka, 25 ACP; 6.35 is the European designa-tion for 25 AUTO)

5.17z G.F.L. 455 MK II (Marketed by FIOCCHI)5.17za Multiple headstamps are a potential indicator of reloaded

ammunition (as different cartridges have different wall thick-nesses, and therefore capacity, pressures, and therefore trajec-tories, may differ from shot to shot).

5.18 17 HMR; 17 MACH 2; .6mm BB; 6mm CB; .22 Short (high velocity)

22 CB Short; .22 CB Long; .22 Short; .22 Long; .22 Long Rifle shot shell; .22 Long Rifle (match); .22 Win Mag; 22WRF

5.19 PMC .22 Long Rifle ammunition: The most common handgun ammunition used today. “Zapper” is the name of the .22 long rifle ammunition shown, which is manufactured by PMC.

5.19a .22 Long Rifle with scale5.19b Cutaway of rimfire model

5.20 Model of a Berdan priming system

5.20a Cutaway model of a Berdan priming system on left; Boxer on

right

5.20b Cutaway model of a Boxer priming system

5.20c Cutaway of a Boxer priming system

5.20d Cutaway of a fired cartridge using a Boxer priming system

5.20e Small pistol (L) and Large pistol (R) Boxer primers

5.21 A rimfire and two centerfire priming systems, Boxer and

Berdan

5.22 Federal Blazer ammunition (Berdan primed)

5.22a Different flash holes in Federal Blazer ammunition

5.22b Cutaway of actual flash holes in CCI Blazer ammunition

5.23. IMR 4064

5.23a Reloader 7

5.23b IMR 4831

5.23c H 380

5.23d Reloader 22

5.23e Universal

5.23f IMR 4320

5.23g Unique

5.23h Bullseye

5.23i IMR 3031

5.23j HP 38

5.23k Winchester Super Target

5.23l FFg Black Powder

5.23m FFFg Black Powder

5.24 Box of ammunition showing weight of projectile, not of the

powder: On this Remington box of ammunition, the 125 grain

Ammunition 103

information refers to the weight of the projectile, which in this case is a brass jacketed hollow point. Powder types and amounts are considered to be proprietary information and not provided to the consumer.

5.25 Destroyed Rossi: The other four chambers were turned to shrapnel in this Rossi revolver. The investigation determined that the cartridge had a double charge of powder. Notice only one chamber of the cylinder is left. The top strap is bent but still in place.

5.25a Destroyed Smith & Wesson Model 29 44 Magnum. Another example of a cartridge with too much gunpowder. The 44 Magnum is much greater in size than the 38 Special. The greater damage (i.e., missing top strap and rear sight) shows a more powerful explosion than seen in the previous Rossi.

5.26 Diagram of a projectile5.27 10 mm and .40 mm S&W5.28 Projectile subgroups5.29 Lead projectiles: Lead projectiles, and cartridges loaded with

different lead projectiles. Lead still is a cheap material. Lead projectiles still are commonly used by major manufacturers and those that reload ammunition at home.

5.30 Round nose lead (RNL) projectile: Notice the wax lubrication in the grooves of the bullets. Projectiles are placed along side the loaded cartridges to show the depth that the projectiles go into the casings.

5.31 Semi wad cutter (SWC): Notice that the projectiles are cone shaped. It is not unusual to find hollow point versions.

5.32 Wad cutter (WC)

5.33 Full metal jacket (FMJ) projectiles: FMJs usually have an

exposed base.

5.34 Total metal jacket (TMJ). These are bullets with a copper

electroplated exterior. Note that the bases are not exposed.

5.34a TMJ projectiles

5.35 Expanding bullets, soft point and hollow point

5.36 Fired projectiles: The three projectiles in the center were fired

into a water tank, which allowed them to expand uniformly

because they were pre-segmented. The bullets on the far ends

are more typical when fired into materials that are not uni-

form (e.g., a human body; target, etc.). It is not uncommon to

have to deal with only fragments of bullets in the investigation

of a shooting case.

5.36a Presegmented expanded fired projectile: The manufacturer

designed this particular bullet to expand uniformly by par-

tially cutting though the jacket material at the nose. Depending

on the material impacted, they may not function as designed.


5.36b Lead .22-caliber projectile removed from a victim’s brain: Only a small portion of the projectile’s surface area is undam-aged and useful for forensics purposes. Notice how the pro-jectile is badly damaged.

5.37 Novelty projectile, Glaser5.37a Tracer ammunition5.37b Triton Quick Shot fragmentation ammunition5.37c Triton Quick Shot manufacturer’s information5.37d Be Safe prefragmented ammunition5.37e CCI 9mm Luger shot shells5.38 Miscellaneous blank cartridges 5.38a Fiocci blank cartridges5.39 9mm Luger: Can you read Arabic? 5.40 6.35 mm ammunition and .25 ACP: Two different names for

the same thing. Notice that the cartridge case dimensions are identical although the projectile materials are different.

5.41 Fiocchi 30 Luger, aka 7.65 Parabellum. Notice that the manu-facturer put two names on the box of ammunition, but not all the different names.

5.42 357, 38+P, and 38 special5.43 Moon clips5.44 Speed loading devices, top view5.44a Speed loading devices, side view5.45 Reloading bench. This is a typical setup for a home reloader.5.45a RCBS single stage reloading press5.45b Dillon model 550 Progressive multistage reloading press5.45c Limon 1200 Digital Powder Trckler Sale5.46 Multiple cracked and bulged cases5.46a Cartridge exploded when sitting on automobile dashboard in

summer heat.5.46b Luger fired in correct firearm with bad timing. Notice

expanded primer pocket in base. This cartridge was not fully

in the chamber nor correctly supported at the rear by the

firearm.

5.46c Case failure caused by worn chamber in firearm. The 40 S&W

cartridge on the left was the correct cartridge for this gun.

5.46d 9mm Luger fired in 40 S&W firearm.

5.46e 32 ACP fired in 32 NAA firearm. The 32 NAA cartridge on

the left was the correct cartridge for the gun. The 32 Auto

cartridge tried to expand to fill the chamber.

5.47 Commercially made dummy (practice) cartridges

5.47a Homemade dummy cartridges

5.48 Impacted primer on the right. Both cartridges still are fully

loaded and capable of firing.

5.49 Close-up of the cardboard wadding at the mouth of the blank

105

6 Fundamentals

INTRODUCTION

The human factor is the vital focus for the future safety of weapon firing. The pro-

fession of human factors and ergonomics brings a long history of designing tools

and procedures to achieve safe operation for all sorts of products, from aircraft to

simple controls and displays. For handguns, it often is described in the analogy of

cooking a soup in a three-legged kettle: One leg of the kettle is knowledge of the

mechanics of the firearm, another leg is knowledge of the ammunition, and the last

leg is knowledge of the human body—the shooting platform. If one leg collapses,

the soup rolls out. In handling and shooting a firearm, safety and accuracy are

lost—sometimes with drastic consequences. In most firearms training programs,

the human factors are described as the fundamentals—the use of the body as a

carrying and firing platform. The NRA defines the fundamentals as the minimal

essential components of a function or structure; in this case, those related to shoot-

ing a handgun (NRA, 1989). These human factors issues are generally broken down

into six basic fundamentals when shooting: grip, stance, breath control, sight align-

ment, trigger control, and follow-through. These basic fundamentals can and should

combine to turn the human body into a stable shooting platform.

One of the most critical issues that bears repeating is the responsibility of the

firearm handler to always be aware of where the muzzle is pointed. This necessar-

ily puts the shooter into a situation of multitasking. The shooter, whether handling

the firearm or actually shooting, divides his or her attention between muzzle con-

sciousness and whatever other task may be at hand. Therefore, it is essential that

training reinforce the importance of muzzle consciousness over any other secondary

concerns.

Frequently, training is incomplete and/or superficial when it comes to the human

factors issues in shooting. Many training programs emphasize practice, but this

often only reinforces improper behavior. NRA instructor Dave Willard warns his

students: “It is not practice that makes you perfect, it is perfect practice that makes

you perfect. Practice only makes permanent what you are doing.” Sometimes stu-

dents are told to do certain actions without the benefit of an explanation as to why.

If they do not understand why they are to perform a certain action, they usually do

not believe, remember, or practice it later. Knowledge of physiology is essential to

understanding the interaction of the mechanics of the firearm and ammunition with

the shooter. The following compilation of information on fundamentals is meant to

be basic and general. Often, the fundamentals are modified to fit the needs of certain

individuals (handicapped, age, strength, physical size) or events (combat shooting,

target shooting, collegiate competition, etc.). With the previous caveats in mind, the

remainder of this chapter is devoted to describing the six fundamentals mentioned

earlier. Foreachoneofthese,failuretoexecutethatfundamentalproperlywill


leadtoeitheraninadvertentdischargeofthefirearmorfiringinanunintended

direction—potentiallyendangeringinnocentbystanders.

GRIP

EYE DOMINANCE AND PROPER GRIP HAND

Before one can learn to establish a proper grip, the decision must be made as to which hand should be used for the weapon and which eye should be used for sighting/aim-ing. The basic rule is that one should use the hand on the same side as the person’s dominant eye. This is not as straightforward as one would assume. The common belief is that if the shooter feels he or she is right handed, he or she should shoot right handed (and vice versa). Consequently, a person who is cross-dominant (i.e., left-handed but with the right eye dominant, or vice versa) usually thinks the dominant hand is the one with which he or she should shoot. A person may try to achieve this, but with extreme difficulty. It is clear that an optimal fit must be achieved between

shooter, weapon, and bodily stability factors. For the shooter to obtain the greatest

stability and control, the ability of the body to work with the firearm must reach the

highest potential possible.

This is where knowledge of physiology comes into play. Currently, few weapon

handling instructors talk about the most basic physiological factors that are impor-

tant in shooting events. Muscle that is used continuously becomes fatigued—usually

manifesting itself as uncontrollable muscle tremors or twitching. Also, muscles that

are tensed reduce the muscular ability to absorb oxygen and to work efficiently.

Some muscles, referred to as flexor muscles, operate to bend a joint and are designed

to contract parts of the body. Others are referred to as extensor muscles, and are

designed to extend parts of the body in certain directions. In a relaxed environment,

you can see the neutral interaction of the muscles by looking at the fingers on the

hands. When relaxed, they are not clenched nor are they fully extended, but are in a

slightly curved or neutral position, which we will refer to it herein as a muscle neu-

tral position (DVD 6.1).

Although not technically correct, an analogy can be made between muscle and

a rubber band. Like a rubber band, muscle has a neutral position. When extended,

a rubber band, like muscle, is in a stress position, and tends to contract; when con-

tracted, it has a tendency to expand back to a neutral position.

When muscle that is not needed to perform the task is used, fatigue, tremors,

and twitching occur, thus disrupting the stability of the shooting platform, which

can result in unintentional or inaccurate discharge of the handgun. When a right-

handed person has a dominant left eye, more muscle is used when the body has to

align the left eye with the right hand (firearm sights) than with the left hand (DVD

6.2). This easily can be seen by looking at the tightening of the muscles on the left

side of the neck. When observed from behind, the body is leaning to one side and

the center of gravity is thrown off, thus compounding the instability of the shooting

platform. With these facts in mind, it is understandable why the correct shooting

hand, referred to as the strong hand, is on the same side as the dominant eye. The

Fundamentals 107

other hand is used to support the strong hand and is referred to as the weak hand or support hand.

Typically, the instructor encounters resistance to changing one’s shooting hand by a shooter who is cross-dominant. The instructor must get the student to understand that muscles can be retrained with correct muscular/skeletal repetitions but not eye dominance. In summary, the dominant eye sets the standard for the grip. This enables the shooter to achieve the best possible position for a stable shooting platform.

PROPER FIT OF HAND AND FIREARM

The proper fit of a firearm to the hand is the first fundamental and is very often mis-

understood by the average shooter. There are many different grip/frame sizes and,

obviously, many different hand sizes. Not every hand fits every grip/frame. To cor-

rectly fit a gun to a hand, the barrel and the grip must be placed in the hand so that

the muscle and bone structure of the hand and arm support the firearm during the fir-

ing process (DVD 6.3). One method used is to find the V formed between the thumb

and the index finger (see Figure 6.1; DVD 6.4) and align that V so that the barrel,

the V, and the bone structure of the arm make a continuous line. The hand should be

placed so that the V is high on the prawl of the revolver or the tang of the semiauto-

matic, but not higher. Italsoisimportanttorememberthatwithsemiautomatics,

thehandshouldnotinterferewiththemovementoftheslideduringrecoil,ora

painfulinjurycouldresult. When the firearm recoils, rather than pushing muscle

or bone into an unnatural position, the arm, in conjunction with the weight of the

body, will act as a shock absorber. More bone and muscle structure of the entire arm

to support the rear of the firearm will allow better support than the thumb muscle

and bone or wrist muscle and bone. Typically, if a hand is too small for a given fire-

arm, the thumb supports the center rear of the grip and is pushed backward at the

time of recoil. If a hand is too big, the center rear portion of the grip usually is seated

into the palm of the hand, and the wrist is pushed back at the time of recoil. Whether

the grip or gun frame size is too big or too small, recoil will push muscle and bone

into unnatural positions that are both uncomfortable and weaken the support of the

V of Hand

Gun in V

Arm, wrist, hand and gun in line with bone structure.

FIGURE 6.1 Correctly (left) and incorrectly (right) sized grips for the hands shown.


firearm. Often,thefirearmwillmoveintheshooter’shand,andanyalteration

ofhowthegunissupportedwillalterthealignmentofthefirearmwiththeeyes,

thusalteringthedirectionoffire.

If the frame of the firearm generally feels comfortable in the hand, but the V of

the hand does not line up on the rear center of the grip correctly, changing the grips

to a wider or overall bigger or smaller grip may be the correct solution. On many

of the popular firearms, hundreds of different styles of grips in many different sizes

may be available. On older, discontinued models, as well as plastic-framed handguns

with nonremovable grips, no grips may be available to adjust to different hand sizes.

Another concern on changing the grips is sharp edges, such as checkering, that may

abrade the skin on the palm of the hand.

DEATH-GRIPPING

Another common error concerning grip is death-gripping the firearm. Often, a

shooter will fire just a few rounds and, upon examining the palms of his or her hands,

see reddish marks and symbols or designs from the grip impressed in the skin. Mus-

cle, to work effectively, must be allowed to receive the oxygen flow from the blood-

stream. Death-gripping, or tightening muscles in any part of the body, slows down

the oxygen transfer. Muscle fatigue and/or involuntary muscle movement (twitching)

typically is the result. The pressure needed to correctly hold the firearm and work

with the muscle structure is often described as that of a firm handshake. If the fire-

arm is held too loosely, recoil—especially on larger-caliber firearms—can cause a

loss of control of the firearm, to include dropping it. If one thinks of the analogy of

a hammer and nail, it is impossible to push a large nail into a block of wood with a

hammer, but if one takes even miniscule taps, the nail eventually will be pounded

into the wood. Likewise, when a firearm is too loose in the hand, it will pound the

hand or can be dropped, becoming at some point uncomfortable and even painful.

USE OF THE SUPPORT HAND

Although most handguns can be shot with one hand, two hands offer more support.

There are two common ways to use the nonshooting hand as a support hand: the cup

and saucer hold and push/pull hold.

Cup and saucer hold. This hold involves using the grip described earlier and

placing the base of the hand and bottom of the grip on the palm of the nonshooting

hand. The cup and saucer hold is appropriate for light recoiling firearms such as a .22

LR. When a more powerful firearm is fired, the hand being used as a saucer provides

practically no support for the wrist (Figure 6.2; DVD 6.5).

Push/pull hold. This second hold is one in which the fingers, wrapped around

the forward portion of the grip, are pushed into a cupped support hand. The fingers

should be together, with the top finger resting under the bottom of the trigger guard.

The thumb of the nonshooting hand should lay on top of the shooting hand thumb in

general alignment with the barrel. When the thumbs are pointed toward the target,

the barrel will generally be in alignment with the target. Care should be taken to

insure that the support hand does not interfere with the trigger finger as the trigger

is squeezed rearward. The shooting hand pushes forward with a slight amount of

Fundamentals 109

force while the support hand wraps around the shooting hand, pulling back with a slight amount of force. The support hand also is supporting both the right and left sides of the firearm. As with gripping the handgun, applying too much pressure

causes the hands to shake, and too little pressure will not provide enough stability

during the firing process. Thus, the shooter is likely to fire the handgun at a point

away from the target, which in a defense situation could result in shooting someone

unintended (Figure 6.3; DVD 6.6). Once a comfortable grip is established it must

be maintained in a uniform manner, as any movement of the handgun in the hand

will change the relationship of the sights to the shooter’s eye. Establishing the same

correct grip consistently will help the shooter hit the target reliably during consecu-

tive shots.

STANCE

Stance is the position that the shooter takes to provide a stable platform for the fire-

arm during the firing process. The more stable the platform, the more likely a safe

and accurate shot. Hollywood’s movies suggest that a number of unique contorted

body positions results in safe and accurate shots fired. The practical side of shoot-

ing suggests that the accuracy was written into the script rather than being based on

reality. Small movements of a firearm in the firing process will result in missing the

target in an exponential manner. The greater the distance to the target, the greater

the miss. In many shooting cases, numerous shots are fired and few hits are noted. If

the platform (i.e., the body) is not generally stable, the projectile will not be directed

correctly to its target. If multiple shots are to be fired, consistency will suffer, affect-

ing accuracy. Inaself-defensesituation,theshooternotonlyislikelytomissan

intendedtargetbutalsomayinadvertentlyhitaninnocentbystander.

Cup and Saucer HoldRight Side

Cup and Saucer HoldLeft Side

FIGURE 6.2. Cup and saucer hold.


We begin by discussing the two commonly recommended standing shooting positions for using a handgun in a self-defense situation, and how failure to properly execute each can lead to either an unintentional discharge or shooting in an unin-tended direction, thus potentially endangering others. These two are the isosceles

and strong isosceles positions. For those readers who may be interested, we then discuss other positions and when they typically are used.

Although one can fire a handgun sitting, kneeling, or standing, the most com-

mon position is standing. One of the determining factors of a standing position is

whether to lean forward, stand straight up, or lean back when firing the shot. This is

often dictated by the caliber or amount of recoil of the firearm. The NRA, in their

The Basics of Pistol Shooting (NRA, 2004b) recommends keeping the back straight

but depict in their photos shooters leaning backward when firing a handgun. Often,

in competition target shooting, when firing a small-caliber firearm such as a .22 long

rifle cartridge, the shooter will assume a position of leaning back to counterbalance

the weight of the firearm. The .22 LR cartridge has very little recoil, and the body

does not receive much of a jolt when firing. Often there is time for muscles to relax

before firing subsequent shots. When the caliber is larger and recoil is noticeable,

such as is typical with handguns intended for self-defense, the shooter is pushed

back. If the shooter already is leaning back, he or she can be pushed off balance,

losing some control of the firearm and putting pressure on the muscle/skeletal sys-

tem—most notably on the back. This causes stress on the muscles, often resulting in

physical discomfort as shooting progresses or when the healing process begins hours

later. Ofcourse,ifonedoeslosehisorherbalance,itpotentiallycanresultin

eitherinvoluntarilyfiringthehandgunorfiringitinanunintendeddirection,

Push/Pull GripRight Side

Push/Pull GripLeft Side

Push/Pull Grip Concept(shown for right-handed shooter)

Both HandsSqueezeSlightly

Both HandsSqueezeSlightly

All forces fromhands balance out.

Left

Han

dLi

ghtly

Pul

lsTo

The R

ear

Righ

t Han

dLi

ghtly

Pul

lsTo

The F

ront

Left

Han

d

Righ

t Han

d

Grip

FIGURE 6.3. Push/pull hold.

Fundamentals 111

thuspossiblyhittinganinnocentbystander(for further explanation, see “loss of balance” in Chapter 2). Size and strength cannot stop the inevitable recoil of a fire-

arm. The body must work with the recoil, transferring the impact to the hand into a

gentler push on the entire body. This can be best accomplished by leaning slightly

into the direction that the firearm is aimed while keeping the heels of the feet on the

ground. If the heels are off of the ground, the forward lean is too much.

ISOSCELES POSITION

The first common stance for use in home defense is the isosceles position. This posi-

tion derives its name from the isosceles triangle, in which two arms of the triangle

are the same length. The triangle is created by holding the handgun out with the two

arms fully extended, both arms being approximately the same length. The shoulders/

back act as the third leg of the triangle. In this position, the feet are nearly parallel

with each other, with the heels being approximately shoulder width apart, outside of

feet to outside of shoulders. The weight of the body should be evenly distributed on

both feet. The legs are relatively straight without locking the knees. When the stom-

ach muscles are slightly tightened the body should lean slightly forward with the

head slightly in front of the shoulders, the shoulders slightly in front of the hips. The

heels of the feet should not leave the ground. The head should be generally erect and

the sights of the firearm brought up to eye level—not hunching the head down to the

firearm, thus contorting and tightening the muscles in the neck. The main muscles

to be used are those that hold the firearm up. When standing behind a person taking

this position, the shoulders should appear parallel to the ground and not slanting to

one side or the other (Figure 6.4; DVD 6.7).

Isosceles Stance

FIGURE 6.4. Isosceles position.


STRONG ISOSCELES POSITION

The strong isosceles (also known as modified) is basically the same as the standard

isosceles with the exception of the placement of the feet. In the strong isosceles,

the nonfiring side foot is placed forward of the firing side foot. The toe of the firing

side foot is about even with the heel of the nonfiring side foot. The position of the

heels is still approximately shoulder length apart with the soles of the feet firmly on

the ground. The forward nonfiring leg is bent and approximately 80% of the body’s

weight is on the nonfiring foot/leg. The rear leg is straight but not locked at the knee.

The body is bent slightly forward toward the target as in the standard isosceles. The

shoulders should be perpendicular to the target (Figure 6.5; DVD 6.8).

In both of the isosceles positions, the body should move, if it moves, in a natural

movement toward the target as it moves back and forth. If, in leaning forward, it is

noticed that the normal movement is across the target rather than straight into it, the

feet should be adjusted to make the natural sway toward the target. Recoil, as stated

previously, is going to push the body regardless of size or strength. If the recoil pushes

the body obliquely, recovering for a second shot will be slower and more muscle will

be needed for support and recovery. Just a slight breeze will move the body, and, if

the body is moving obliquely, the sights will be aligned on the target less than if the

natural movement is toward the target. The feet being shoulder length apart provides

the body stability like a column. When the feet are farther apart, the body has more

FIGURE 6.5. Strong isosceles position.

Fundamentals 113

area to cover and tends to have an oblique natural movement. When the feet are too close together, the body can wobble in multiple directions like an upside-down tri-angle, which obviously is less stable. Correct feet placement allows for more control of natural body movement and therefore more stability. Both isosceles positions are relatively stable standing positions and, in addition to being recommended positions for self-defense, are frequently used by both competitors and informal target shoot-ers with success. On the tactical or practical side, the body/chest faces the threat per-pendicularly. The chances of having multiple vital organs—such as both lungs, the spinal column, heart, and major veins and arteries—exposed to a threat are lessened. As has been noted in NRA courses as well as elsewhere, numerous deaths of police officers have been due to exposure of the armpit area that often is exposed to a threat;

this area generally is not protected by protective vests. But like so many decisions in

the shooting world, there is a negative side in that more body is exposed.

Aswiththestandingposition,ifonefailstoexecutetheisoscelespositions

properly,thatpersonislikelytofireoff-targetand,potentially,coulduninten-

tionallyhitsomeone.Ifthepositionassumedisunbalanced,thepersoncould

possiblylosehisorherbalanceandinvoluntarilydischargethehandgun.

OTHER POSITIONS AND THEIR USE

Benchrest Position

Although standing is the most common position for a handgun shooter, a position

referred to as the benchrest position is the recommended starting position for sight-

ing in a firearm. The benchrest is a position where the hands and body are more

supported. The firearm sights can be adjusted, taking as much of the human fac-

tor as possible out of the firing equation. In the benchrest position, the shooter is

sitting down, facing the target in the direction the shot will be fired. The handgun

is supported by placing the wrists on sandbags, which are stacked and sitting on a

bench or table. All of the fundamentals that are discussed apply to firing a supported

shot from this position. The table or bench should not move or rock. Feet should

be firmly on the ground approximately shoulder width apart. The body should be

leaning forward with the firearm raised up to the shooter’s eye level by means of the

stacked sandbags. The arms should be outstretched, fully extended, with the fire-

arm gripped using the strong hand. The weak hand should be supporting the strong

hand as discussed previously. If the table is solidly in place, leaning forward where

the chest touches the table also eliminates some body movement. Specific sight-in

tables, often made of steel, are common on many ranges. Generally, the first few

shots should be fired in this position to verify sight alignment. Because the body

has more support, felt recoil will increase as compared with what is felt in standing,

nonsupported positions (DVD 6.9).

The Weaver Stance

The Weaver stance is a position developed by a Los Angeles sheriff’s officer. The

basic premise to this position is that a handgun may be held more like a rifle. The

position differs mainly in that the body is perpendicular to the target, allowing for


less exposure to threats. The tactical trade-off is that more vital organs of the body are in fact exposed to a single wound—for example, lung to lung, not to mention multiple arteries, veins, heart, and spinal column in between. The firing arm paral-

lels the upper chest (pectoral area), just above the breast, in a breast-to-near-breast

position. This causes the pectoral muscles to bunch on the right side and act as a rest

or support for the upper arm. The support arm is bent in a V, like a bridge support,

with the support elbow pointing downward. The upper arm may be tucked to the

pectoral area of the chest or out slightly diagonal from the chest. The shooting arm

may be extended out and locked, which increases the distance from the shoulder of

the support side to the support hand. Another modification is to bend the shooting

arm, bringing the sights closer to the eyes and shortening the distance from shoul-

der of the support side to the support hand. Foot position is similar to the isosceles

positions in that the feet are generally shoulder length apart with the weak side foot

forward and the strong side foot perpendicular to the weak side. The weak side knee

is bent generally toward the target, and the back leg is straight but not locked. The

Weaver position requires greater flexibility and uses considerably more muscle to

hold in position (DVD 6.10).

One-Handed Standing Position

The last position to be discussed is the one-handed standing position. This position is

the least stable of all positions mentioned so far and places the body in greater jeop-

ardy due to exposure of more vital organs. Considered the classic position (NRA,

1991, p. 81), it is used often in competition as a more challenging position. On the

tactical side of shooting, there are a number of reasons to learn this position, such as

if your shooting arm is injured, you are on the phone with the police, or you are hold-

ing a child. Although it is best to use the hand on the side that matches the dominant

eye, either hand can hold the handgun. The body can be at a 45° angle to the target

or perpendicular to the target. The feet are shoulder length apart. The nonfiring

side hand and arm must be placed in a position where they do not move. Movement

of the nonfiring hand/arm during the aiming/firing process causes the firing-side

hand/arm to move much like a child’s teeter-totter. Usually the hand is placed in

the pocket or the thumb is hooked on a belt or belt loop. Tactical instructors often

recommend placing the nonshooting hand and arm across the chest to provide some

limited protection to the chest and vital organs. If the nonfiring side arm is bent out

like a chicken wing, a slight breeze can cause movement in the shooting hand, thus

interfering with proper sight control (DVD 6.11).

Another one-handed stance that is more tactical is to stay in the isosceles posi-

tion and use the support hand for phone calls and so forth. This is essentially a

one-handed modification to the strong isoceles stance, so that there is very little

movement when transitioning from two-handed to one. In addition, training for the

stance is more natural because, through numerous repetitions, the body is already

used to being in that position.

A simple exercise to understand muscle relationship in the body between the

weak and strong sides is to line up your eye with the point of a pencil on a distant

target (such as a light switch on a wall) with the strong hand. When the weak hand

Fundamentals 115

is still, it is relatively easy to hold the pencil on target. When the opposite hand is moved (straight out making circles works well), it is difficult if not impossible to

keep the pencil on target. Because all muscles are interconnected, it has been proven

that if only the strong arm is exercised the weak arm will still show some strength

gain (Enoka, 1991). Increased heart rate during stress also will increase the difficulty

of keeping sights on target.

BREATH CONTROL

When one inhales, the lungs expand, pushing the head and shoulders up. When one

exhales, the lungs deflate, causing the shoulders and head to move down. This means

that when normal breathing takes place, the body is almost always moving. A simple

demonstration of this would be to point your index finger at a small object across the

room. Watch the motion of the finger as you breathe normally. You will notice the

finger moving up and down during the normal process. If you were aiming a firearm

at a target and breathing, you would notice the firearm moving in an up-and-down

motion during the breathing process. Therefore, shots that were fired would also be

hitting in a linear pattern up-and-down on the target. When you hold your breath,

the movement caused by the breathing process would stop, but not in a consistent

position unless the amount of air in the chest was generally consistent. It is techni-

cally impossible to keep the body perfectly still. Just the beat of the heart and blood

rushing through veins and arteries will cause some movement. The practical method

to using the body as a more stable platform would be to exhale the carbon dioxide

(the waste product of the body), inhale a fresh breath of air until the amount of air

in the chest feels relatively comfortable, and then hold that position. The average

shooter can typically hold his or her body relatively steady for 6–8 seconds (NRA,

2001). After 6–8 seconds the muscles require oxygen, or twitching/involuntary mus-

cle movement will result. If the shooter does not fire the shot within that 6–8 second

time frame, the breathing process must be repeated.

In a target shooting situation, when the muscles are fatigued, the handgun should

be lowered and holstered or laid down to allow the muscles to recover. After the

needed period of recovery to allow the muscles to relax by taking a few breaths,

the shooting process can begin again. In a tactical situation such as self-defense,

this often is not possible. Failuretoexerciseproperbreathcontrolcanresultin

shootingoff-target,thuspotentiallystrikingsomeoneunintentionally.

SIGHT ALIGNMENT AND SIGHT PICTURE

Correct sight alignment is simply lining up the front and rear sights; the front sight—

often a tall, thin rectangular metal piece, as viewed through the rear sight, protrud-

ing from the front top of the barrel—is aligned with a notch at the back end of the

frame, which also is known as a receiver (DVD 6.12). The top of the front sight

should be level with the top of the rear sight, and the front sight should be centered

in the slot of the rear sight. Sight picture is the relationship of the eye, rear sight, front

sight, and target. Correct sight alignment/picture is important to accuracy.


A drill for beginning shooters is to aim the handgun and look at the rear sight. When they see the rear sight perfectly clear they will notice that the front sight and target are both slightly blurry. Then the focus is changed to look at the front sight so that it is perfectly clear and the rear sight and target are both slightly blurry. The focus of the eyes is changed to the target through, and in conjunction with, the sights so that the target is clear and the sights are noticeably blurry. This teaches that the eyes can only focus on one thing at a time (DVD 6.13).

The drill then goes to bracket the target with the rear sight; the focus should be on the rear sight. Then bring the front sight into position where the top of the front sight is level with the top of the rear sight and centered in the rear sight slot, in gen-eral alignment with the target. The focus should be on the front sight and the rear sight should be slightly blurry, but the outline of the rear sight is visible. Next look at the target to insure that it is what you want to shoot at, and align the sights on the center of the slightly blurry target. Lastly, come back and focus on the front sight keeping a clear front sight aligned with a slightly out-of-focus rear sight and target. Typically, a beginning shooter can hold the sights correctly on target for about 6 to 8 seconds. It is not possible to hold the sights perfectly in alignment on the target; just the normal heartbeat in a body causes some movement in the firearm’s sights. When

you add in holding the weight of the firearm stretched out, and environmental factors

such as wind, movement will be noticed by the shooter in the sights. This move-

ment is referred to as the arc of movement, it cannot be eliminated, only controlled.

Often, shooters control the movement by making small circular motions with the

front sight. As the circle gets smaller it is easier to keep the sights generally on target

with a small amount of controlled motion.

As previously mentioned, there are a wide variety of sights, and different sights

may be appropriate for different purposes. A bullseye target shooter typically would

use target sights that are black rear-sight aligned with a black front sight. The sights

are aligned so that the bullseye target (a black circle of a known diameter on white

or light-colored background paper) rests on top of the aligned sights at a known

distance, much like a ball resting on posts, the circular target being the ball posi-

tion. When aimed, the sights have a light background to aid in location/alignment

discrimination. The sights are adjusted with the trajectory of the firearm so that

when the bottom of the circle rests on top of the aligned front sight, the bullet will

travel and hit the center of the target. This is known as a six o’clock hold (DVD 6.14).

Because of the projectile’s arced trajectory, if distances change, the impact point also

changes. Many bullseye target guns have front sights that can be adjusted to com-

pensate for specific changes in muzzle-to-target distances as well as rear sights that

adjust for windage (left-to-right adjustment) or elevation (up-and-down adjustment).

Although firearms equipped with these style sights are appropriate for bullseye tar-

get/competition shooting, use for other types of target shooting or for self-defense,

where distances or target size change, would be a hindrance. Imagine putting a black

rear sight on a black front sight on a total black target; the difficulties the eye would

have in discriminating the rear sight from the front sight from the target become

obvious. Low light levels, which are common in self-defense or combat, further

compound the problem.

Fundamentals 117

On the other end of the spectrum, small-frame concealable firearms used for

concealed carry backup by law enforcement, or for personal self-defense, often have

small sights that are not adjustable. These are known as fixed sights, and are very

durable and difficult to damage. Fewer sharp edges to catch on clothing when draw-

ing the firearm, as well as overall size and concealability, is more important. Often,

the rear sight is nothing more than a small notch at the rear of the top strap, and the

front sight is a protruding piece of metal over and on top of the muzzle. Typically

the sights are the same color and material as the frame, thus hindering sight picture

entity discrimination. Many modern firearms are stainless steel and/or nickel that

allow greater light reflection off of the top surface of the firearm, thus interfering

with sight alignment. Some manufacturers take the top smooth portion of the frame

and alter it from a smooth, shiny finish to a dull, rough finish to minimize reflection.

When the sights are aligned with similar-colored targets, the same problem exists

as with black sights and a dark background. Light becomes the obstacle rather than

darkness, but sight shape distinction is more difficult. Some manufacturers also ser-

rate the top of the slide to mitigate this problem, although it tends to be an aftermar-

ket modification.

Another type of sight is the semiadjustable sight. Semiadjustable sights can be

moved left and right for windage but there is no elevation adjustment. They are usu-

ally found on the top rear of the frame. Semiadjustable sights are more durable than

adjustable sights and provide movement for alignment that fixed sights do not.

There has been a trend in the past few decades to add geometric shapes to aid

in the eyes’ ability to focus on a given point, as well as to aid in correct alignment.

Sights for general informal target shooting and self-defense are typically aligned dif-

ferently than for competition target-shooting. The need for pinpoint accuracy in self-

defense is not as crucial, as the area that will incapacitate a human or animal threat is

larger than most target shooting targets. Generally, the distances are closer, making

the arc of travel or trajectory of the projectile less critical. Sights on most nontarget

shooting guns are aligned on a center mass hold, which means they are aligned so

that the bullet will strike at the top edge of the front sight when aligned for a spe-

cific distance (DVD 6.15). Generally, the sight-in distance is 25 feet for self-defense,

although 50 feet is relatively common also. The lower striking point of the projec-

tile from 6 feet, a common self-defense shooting distance, is relatively insignificant

when the firearm is adjusted for 25 feet. The sight-in range usually is dictated by the

expected use (self-defense, competition, hunting, etc.) and the shooter’s ability.

The patterns and alignments of the sights on the target can be very different;

each is utilized in a different manner. When a shooter tries to align a sight better

suited for target shooting on a round bullseye target using a center mass hold, it

is difficult to see when the sights are level with the center of the target. Likewise,

when distances are unknown, can change rapidly, and/or pinpoint accuracy is not

critical, center mass hold is more appropriate. Because target colors as well as back-

ground colors can change rapidly, informal or self-defense shooting manufacturers

have developed a number of different patterns to accent and allow the eyes to adjust

more quickly.

Shooter familiarity with sight patterns is important for correct use and perfor-

mance. Three common sight patterns are as follows.


White outline rear sight, red front sight. The white outline, open box shaped lines outline the rear sight and are used to bracket the target, and the front sight is held so that the point of impact on the target is divided by the top of the colored portion of the front sight.

Ball and post. The post painted on the bottom of the rear sight is aligned with the ball resting on the post and further aligned with the target so that the ball is on top of the point of impact.

Three dot. One dot is painted on the rear of both sides of the rear sight, and one dot is on the center of the front sight. The dots are aligned so that they are parallel with the center dot of the front sight on the point of intended impact.

There are also sights that can be used for night /low-light shooting called night sights.

They use material similar to the luminous hands and dial of a watch that can be seen at night—enough to see the sights but not so much that it gives away position.

As can be seen, there is a great deal of variety among sighting systems, and each has a negative and positive attribute. Sights can aid the shooter or be detrimental in certain circumstances. Intended use, individual training, and experience will deter-mine what sight is best for specific purposes.Failuretohavethepropersightsfor

self-defensehandgunuse,ortohavethemproperlyaligned,canresultininac-

curateshooting,thuspotentiallyendangeringothersinsomesituations.

TRIGGER CONTROL

Trigger control generally is thought of more in terms of mechanical issues rather

than human issues. Both need to be understood well to put them in the correct con-

text. Mechanically general terms are used to describe what a trigger may feel like

when pulled; some are:

Rough—burrs or machine marks rubbing against one another during the trigger-

squeezing process.

Smooth—internal parts polished to reduce felt friction.

Long—refers to distance trigger must be squeezed to initiate the firing process.

Short—slight movement in the trigger to initiate the firing process.

Heavy—strong resistance to felt movement of the trigger usually implies

difficulty.

Medium—controllable resistance to felt movement of the trigger.

Light—sometimes referred to as a hair trigger, a slight squeeze causes discharge.

These terms are relative and not scientific and can be different for shooters of differ-

ent strengths and ability. The context of use may make a 2.5 pound trigger appropri-

ate for one use, such as a particular contest, although inappropriate for others, such as

home defense. The physical ability, strength, and size of one shooter may not be the

same as another, thus making control easy for one but hard for another. The amount

of appropriate training one person has versus another, not only with general firearms

but with specific models as well, will make a difference in ability to be safe as well

Fundamentals 119

as accurate. The amount of muscle in the trigger finger is little compared to other

parts of the body. Appropriate exercises of the trigger finger will result in increased

ability to correctly squeeze the trigger relatively quickly for most shooters.

There are many parts in a firearm that must work in a synchronized manner,

much like parts of a watch. Ifonepartisoutofalignment,thenthefirearmmay

notfunctionsafely or at all. Single-action revolvers require the hammer to be manu-

ally pulled to the rear, thereby moving all of the parts into the correct place for firing.

When the hammer is pulled, the trigger usually disengages a gear that releases the

hammer. The amount of force needed to pull the trigger is relatively light, and the

distance the trigger finger needs to pull the trigger to discharge the firearm is usu-

ally very short—under 1/8 inch on many single-action models. On double-action

firearms the trigger has to be pulled farther to compress springs in the firing system

and overcome friction as parts rub against one another, moving to the point of dis-

charge (DVD 6.16). Due to the design of many traditional double-action handguns,

and as best seen in revolvers, the hammers do not come back as far in double action

as they do in single action. The spring being compressed that powers the hammer in

double action forward will not be compressed as fully and therefore not be thrown

forward with as much force as can be obtained in single action. It also is important

to remember that the trigger does not have to come back as far to release the hammer

and fire the gun.

Triggers on firearms can be different in many other ways beyond the differ-

ences noted in single and double action. Some triggers may be wide and others thin.

Some will have serrations, whereas others may be polished smooth. The direction

the trigger travels to the rear can be different as well. As noted in Chapter 4, on most

revolvers the trigger travels in an arc to the point of discharge, while on many semi-

automatics the trigger rides in a channel straight to the rear. The amount of pressure

to discharge the firearm can vary from gun to gun—even in the same makes and

models. Also, it is not unusual to have slight inconsistencies in the weight required

to discharge the firearm in the same gun.

Measuring the weight of trigger pull. The energy necessary to pull the trigger

back to the firing position is often misunderstood. The phrase weight of trigger pull

is a term of measurement of how many pounds of weight placed on the trigger will

result in discharge of the firearm. There are numerous different systems for measur-

ing the weight needed to discharge a firearm: dead weight (DW), force gauge (FG),

spring gauge (SG), and different mechanical/computer systems. The most simplistic,

yet relatively accurate, is the dead weight system. The DW system uses a rod attached

to the trigger on which weights are added to determine the number of pounds required

to cause discharge. Because of the differences in direction (i.e., arced or straight) that

the trigger moves back when pulled, it should be understood that this is a mechanical

measurement that may not reproduce the weight as subjectively felt by the shooter.

For practical purposes, a trigger is simply a lever. Where the weights are placed

on the trigger (or, for that matter, where the finger is placed on the trigger), high or

low, can cause fluctuations in the measured weight to cause discharge. As different

shooters will place their hands differently on a firearm’s grip and frame, and their

fingers differently on the trigger, this makes measurement an art as well as a science.


Thus, mechanical measurement of the weight of trigger pull is but an estimate of the force that is utilized by a given shooter in order to fire the handgun.

In considering the adequacy of the weight of pull for a given handgun, the shoot-

er’s physical strength also must be considered. What is easy for the average man can

be difficult for the average woman or child. When we consider finger pull strength

for the entire adult population, it should be noted that the relationship is not linear

throughout the range. Put simply, those at the high end of strength and ability have a

much stronger pull strength capability than those at the low end. Also, what is easy

for someone who has been trained and has practiced may be difficult for the inexpe-

rienced. In addition, chemical reactions in the human body, such as the involuntary

adrenalin rush people experience when under acute stress, significantly increases

hand and finger strength (Selye, 1976), thus causing them to squeeze the trigger with

much greater force than when not under stress.

One important implication of the previously mentioned has to do with the issue

of intent in legal proceedings. Often in legal proceedings, the weight of trigger pull

is mistakenly used by itself as a measure of intent: The heavier the weight of pull,

it is alleged, the more likely the suspect formed the mens rea, or mindset, to fire

the gun. Mechanical firearms experts often will testify to how difficult pulling 10

pounds with the trigger finger is without consideration of the other human factors

involved, such as those covered here and in previous chapters. To further put things

in perspective, many toy firearms for children in the 6- to 10-year-old age bracket

have significant weight of trigger pulls ranging from 6 to 12 pounds. If a child can

pull back the triggers of his or her toy guns with little difficulty, then the real gun’s

trigger pull can be put into a more realistic context.

The practical side of how heavy a trigger’s felt pull can be is based on what the

shooter can effectively pull comfortably while holding the firearm correctly. The

trigger must be pulled in a manner in which the sights are not moved off of the tar-

get, whereas the trigger finger is pulling the trigger back. The heavier and longer the

trigger pull, the more likely the sights will be pulled off target.

Squeezing the trigger on a handgun is much like squeezing an eyedropper. If

not enough pressure is used, nothing comes out. If too much pressure is used, the

liquid comes out too fast and not necessarily where we want it to go. When the right

amount of pressure is used, the one drop we need will likely go where it is needed.

When a trigger is jerked back sharply, control of where the sights should be aligned

is lost. Lackof triggercontrol is thegreatestcauseof inaccurateshotsbeing

fired.The correct trigger squeeze should be a straight smooth squeeze to the rear in

which the sights remain on target. One of the common errors made by shooters that

interferes with the correct trigger control is the incorrect placement of the finger on

the trigger. When too much finger is placed on the trigger, the muzzle is pulled to the

strong side. (A right-handed shooter will pull to the right, a left-handed shooter to

the left.) When too little finger is used, the muzzle will be pushed to the weak side.

If too little finger pushes the handgun, and too much pulls it, then there is a spot on

the finger that, when correctly placed on the trigger, will result in the gun’s muzzle

not moving either to the left or right when squeezing the trigger. This position is the

center of the top pad of the trigger finger, or halfway between the tip of the finger

and the top (first) index—not on the joint itself. This position feels uncomfortable to

Fundamentals 121

many shooters and they tend to slide back to the joint versus the correct position. As a visual reminder, many instructors will draw a line on the student’s finger to help

him or her remember the correct finger placement. Consistent practice of putting the

finger in the correct place helps the student to remember the correct place as well

as getting over the discomfort of doing something different. An analogy often used

is the discomfort one feels with driving a different model of car than one that you

are used to. The repetition of having to put the key in a different place, or different

pressure on the gas or brake pedal, causes the discomfort to go away after a rela-

tively short period of practice. The correct finger placement can change slightly from

model to model. Practice with dry firing helps the shooter to overcome differences,

but the key to detection of improper trigger control will be watching for movement

in the front sight and sight picture as the trigger is being squeezed. Left and right

movement of the front sight often is because of incorrect placement of the finger

on the trigger. Other movements of the fingers and hands also will cause incorrect

movement of the muzzle and an inaccurate shot; these are discussed in greater detail

later. Sight alignment and trigger control must be done simultaneously during the

firing process. A common error in trigger pull is jerking the trigger backward, often

causing the muzzle to dip down left for a right-handed shooter and down right for a

left-handed shooter.

FOLLOW-THROUGH

When a golfer drives a ball (exemplified marvelously by Tiger Woods), there is no

motion stop when contact is made with the ball by the club—instead, there is follow-

through. That is, the motion of the swing continues in a smooth path after contact

has been made. Tennis, bowling, baseball, and a number of other sports also have

follow-through as a final step in the delivery procedure. The action does not stop.

Instead, a smooth, continuous motion follows through the delivery. In shooting a

handgun, follow-through also exists. It is the act of holding the front sight in align-

ment with the rear sight correctly on the target until the recoil pushes the sight off of

the target. Regardless of strength, there will always be recoil. It is not felt until the

moment that the projectile is leaving the barrel. Practicing correct follow-through

with a handgun is best put into practice by watching the front sight during the fir-

ing process and attempting to keep the front sight from moving off of the target. If

a shooter keeps the front sight in focus during the shot, one can call the shot or be

able to tell what direction the projectile went when it was fired and often how much

it went off. If the front sight moved to the left, then the shot will have moved to the

left. Ideally, there should be no (little) movement in the body or firearm other than

the movement of the finger backward to the firing point until recoil forces movement

as the projectile leaves the barrel. If the recoil pushes the shooter straight back, then

there will be little deviation from the intended point of impact.

Some common errors for shooters in the follow-through process are the failure

to keep the front sight in focus (watching the target), relaxing too quickly, pushing

out on the firearm in anticipation of recoil, immediate forward movement of the

trigger finger upon release of the hammer, shutting both eyes at the time of firing,

and tightening or tensing part or all of the hands, arms, or body during the firing


process. All three authors committed these errors when first learning to shoot. Itis

notdifficulttoseehowtheseerrorswouldbemadebyvirtuallyalluntrained

personsandcouldresultinanunintentionalshooting.

Any movement beyond the trigger finger coming straight back causes movement

of the front sight and a change of direction from the intended point of impact. Some

of these errors that show up during the follow-through phase are further explained

as follows:

FAILURE TO KEEP THE FRONT SIGHT IN FOCUS

As explained in the sight picture/sight alignment fundamental, it is self-evident that

whichever direction the front sight moves, the projectile also moves. Often, shoot-

ers are more interested in where their shot has gone than in the steps necessary to

get the bullet where they want it. The focus ends up being on the target rather than

on the key indicator of where it is going, the front sight. More often than not, there

is a lack of training or, when training has been received, a failure to remember or

believe in the shooting fundamentals. Often the shooter looks through the rear sight

but subconsciously pushes the front sight out of the way while attempting to see the

target and where the bullet impacts. Using a clock format with the center being the

target, the impacts are often below the line made from the 3 o’clock to 9 o’clock posi-

tion. As distance to the target increases, so does the tendency of wanting to look at

the target, rather than the front sight, as what should be a slightly out-of-focus target

gets more blurry.

RELAXING TOO QUICKLY/BREAKING AT THE WRISTS

Often, shooters pull the trigger, and, before the firing process is completed, they are

letting out their breath, causing the arms to drop and relaxing hand and arm muscles,

which allows the handgun to drop even further. This causes impacts to below the

center of the target if there is no other movement left or right during the relaxation

period. Another cause for impacts below center is bending the wrists downward in

an attempt to anticipate and compensate for recoil.

PUSHING FORWARD BEFORE DISCHARGE

Pushing forward as the trigger is squeezed to the rear is another form of recoil antici-

pation behavior. Often, the muzzle is pushed downward and the strike of the projec-

tile is low.

IMMEDIATE FORWARD MOVEMENT OF THE TRIGGER UPON HAMMER RELEASE

Shooters sometimes release the finger immediately upon release of the hammer.

While the time it takes for the hammer to fall is measured in thousands of a second,

continual movement of the trigger finger is communicated to the rest of the firearm,

particularly to the muzzle. It is unknown which way the projectile travels, but often

the finger is moving up and out and the shot follows the direction that the finger is

moving. Premature releasing of the finger has been discussed by Paul Paradis with

Fundamentals 123

numerous shooters, and it is unclear as to whether it is a form of anticipation or relax-ing too quickly, or both.

SHUTTING THE EYES

Obviously, when the eyes are shut, the shooter cannot tell if the sights stayed in alignment with the target. Generally, there is no clear pattern on the target. This error is hard to determine because the coach or instructor cannot see the closure of the eyes during the firing process. Student shooters often can only guess at the direc-

tion the front sight moved, further complicating determination of accuracy.

TENSING MUSCLES AT THE MOMENT OF FIRING

Shooters react differently and often subconsciously to what is unpleasant. Often

there is a fear of the noise and felt recoil of the firearm. Typically the tightening of

muscles, a form of anticipation, in the shooting platform creates movement in the

firearm. Of particular interest is the tensing of muscles in the hand, which commu-

nicates the movement directly to the firearms muzzle. When any portion of the hand

is tensed, there is a push or pull on the firearm. An example of this that is common is

the shooter tightening his or her grip as the trigger is pulled. This tends to cause the

muzzle to dip at the time of discharge.

Another common movement of the hand is the thumb pushing against the side of

the firearm, thus pushing the muzzle to the right for a right-handed shooter and left

for a left-handed shooter. The corrective action is to identify what muscles are being

used beyond the trigger finger’s normal movement and eliminate the unnecessary

movement. When the trigger reaches the point of release, it should be held there until

the projectile has left the muzzle. Some firearms have a mechanical block placed on

the frame behind the trigger to stop the overtravel of the trigger and reduce unneces-

sary movement of the trigger finger rearward.

METHOD FOR CORRECTIVE ACTION

It is easy to see that thepreviouslymentioned factors, in causing inaccurate

aimingofthehandgun,canpotentiallyresultinanunintentionalshooting.It

alsoiseasytounderstandthatuntrainedpersonsareverylikelytocommitsome

combinationofthepreviouserrors. Thus, the answer is training and practice.

Dry firing is practicing with an empty handgun. The potential fear of the noise

and recoil of live firing is removed from the training process. The student can learn

the amount of pressure that is needed to fire the firearm. Another corrective action

is one taught by the NRA and referred too as a ball-and-dummy drill. This method

requires the use of a shooter and coach; the coach hands the shooter a firearm that

may or may not be loaded. When the shooter fires the firearm, it may or may not fire.

When the trigger is squeezed and no cartridge is present, it is relatively easy to see

unnecessary movement by the shooter and determine what caused this movement.

After the corrective action is determined, it is followed by having the shooter prac-

tice proper procedure using a known unloaded firearm until the proper procedures

are followed. Ball-and-dummy drills are continued, alternating with dryfire drills


as needed. For this training to be most effective, it is important for the shooter to determine on his or her own what mistakes were made and what the corrective action should be. It has been found through experimentation on the range that when a stu-dent recognizes individually what mistakes have been made and what most likely caused them, learning and improved accuracy takes place more quickly than when, instead, the instructor repeatedly tells the student what happened.

A chart often used for determining what mistakes are likely is exemplified by

the one in Figure 6.6 (and DVD 6.17). Notice the difference between left- and right-

handed shooters.


DVD # Description

6.1 Eye, correct and wrong. The muscle tension because of using

the non-dominant eye is easily seen.

6.2 Relaxed hand. Notice that in the rest position the hands are

neither out straight nor clenched. This relaxed state is referred

to as the muscle neutral position.

FIGURE 6.6. Handgun target analysis guide.

Fundamentals 125

6.3 Effects of hand too low on grip. When the trigger finger is

coming at an incorrect angle on the trigger, it will increase

the difficulty of making a smooth continuous squeeze of the

trigger (tracked trigger)

6.3a Effects of hand too low on a trigger that swings. This also

adds to the difficulty of keeping the sights aligned on the tar-

get. In the investigation of a firearm, the travel of the trigger

should be documented.

6.4 Arm, wrist, hand and gun in line with muscle and bone

structure

6.5 “Cup & saucer” hold. This hold provides little support of the

firearm during the firing process.

6.6 “Push pull” hold

6.6a Thumb positions. It is important that the thumbs do not inter-

fere with the squeeze of the trigger. When the thumbs are par-

allel to the barrel and pointed at the target, the sights will be

aligned towards the target as well. Some shooters prefer to

place the non-firing thumb on top of the firing thumb so that

their grip is not altered during the reloading process, or when

using the support hand for any other purpose, such as picking

up a phone.

6.7 Isosceles stance

6.7a Isosceles stance showing the isosceles triangle

6.7b Movie: While doing a defense investigation, a small in stat-

ure woman attorney test fired her client’s powerful handgun.

As a safety precaution, author Paul Paradis would only allow

her to have one cartridge in the gun at a time. Notice that

during recall, the muzzle of the firearm comes all the way

back to where it is pointed at her forehead. Using the isosceles

stance and the “push pull” hold, she never was knocked off

balance—nor did she drop the handgun.

6.7c. Movie: The average shooter can shoot approximately three

shots per second. Author Paul Paradis in this movie, despite

his large size and strength, cannot stop the recall, only man-

age it. When there is more than one round in the gun, it is

easy to fire multiple shots very inaccurately during the recoil

process.

6.8 Strong Isosceles stance

6.9 Benchrest position

6.9a Benchrest position with a coach observing

6.10 Weaver Stance

6.10a Weaver stance variation

6.11 One handed stance, body perpendicular (90 degrees) to

target

6.11a One handed stance, 45-degrees to target


6.11b One handed variation. The strong isosceles stance with the support hand being used for a different task. Notice that the head is slightly in front of the shoulders, the shoulders slightly in front of the hip, and hip slightly in front of the heel of the rear support foot.

6.12 Diagram of sights 6.12a Sight pictureas viewed by the shooter This is what a sight picture looks like when the shooter cor-rectly aligns the sights on the target. Notice that the rear sight and the target are slightly blurry, but visible, and the front sight is clear and sharp (this is a center mass hold).

6.13 Sight focus. The lens on the camera, just like the human eye, cannot focus on two distances at the same time, but the focus can be changed very rapidly by the eye to go from the rear sight, to the front sight, to the target.

6.14 6 o’clock hold. This hold is used by target shooters when fir-

ing a known distance at a round bulls eye target. The sights

are adjusted so that when the round target rests correctly

on the sights, the projectile will be directed to the center of

the target circle.

6.15 Center of mass hold with correct alignment

6.16 Rough machine marks in side action: One cause of heavy trig-

ger pull

6.17 Target analysis clock for a right-handed shooter. Every minor

movement will send the projectile in a different direction than

what the shooter intended. The greater the distance to the tar-

get, the greater can be the miss. For example, if a shooter

missed by 4 inches at 10 feet, at 50 feet it would be 20 inches

off – enough to hit someone, or something, else!

6.17a Target analysis clock for a left-handed shooter. Notice that a

left-handed shooter’s errors will be the opposite of those of a

right-handed shooter.

127

7 Safety Rules

The Search for Commonality

INTRODUCTION

One would think that safety rules for handgun use would be standardized. Unfortu-nately this is not the case. A real problem is that there are three different domains to consider—military, law enforcement, and civilian. Civilian use, in turn, can be bro-ken into three general subgroups: firearm games/contests, hunting, and self-defense.

Law enforcement, which has been developing paramilitary training and tactics to

complement normal patrol duty, also can be broken into different subgroups (as well

as the military). For example, law enforcement has uniformed patrol, detectives,

undercover, and sniper-trained personnel. Military uniformed combat forces can be

offensive and/or defensive against heavily armed manned forces that require fire

and maneuver with a combination of armor, artillery, and air power. Sniper and

unconventional warfare units also exist. Collateral damage and damage to noncom-

bat forces is more acceptable and, in fact, expected to some degree in military action,

yet is very unacceptable in normal law enforcement action. Given the sophistication

of techniques and firearms used by the criminal element, weapons and tactics in

larger populated urban areas have taken on a more military aspect but are still not

the same. An infantryman in the army and a patrol officer may both be armed with

an M16-type fully automatic rifle, but the training and rules of engagement will be

very different. Add into the mix that a semiautomatic rifle of nearly the same style,

speed, and power can be used for fun, sport, or self-defense by the average citizen,

and one can understand that one set of safety rules will not be applicable to all.

DIFFERENT ORGANIZATIONS HAVE DIFFERENT AND CONFLICTING SAFETY RULES

As an instructor, one of the first problems that one of the authors, Paul Paradis, has to

deal with is that each organization (this can be many when one includes the different

types and locations of law enforcement and military units) considers its safety rules

to be the correct ones.

TWO EXAMPLES

Example 1. When a court order was issued that the defense be allowed to test a shot-

gun at the local police firing range, the range master was concerned that someone he

did not know was going to place his range in legal liability if something went wrong.

He tried to direct testing with which he was unfamiliar. He began by asking general

questions about the firearm to be used and questions about the three main safety


rules, testing the author’s (Paul) knowledge and ability. The author answered the questions appropriately except, in the range officer’s opinion, the last one. The author

used the NRA third civilian rule of “keep the firearm unloaded until ready to use,”

but the range officer wanted the third rule used by the Colorado Law Enforcement

Training Academy at his facility. This was “to know your target and what is beyond.”

His rule was very appropriate for an officer on the street but not as appropriate for

forensic testing at a target at very close ranges, with multiple spectators watching

and filming close together on an enclosed range. This form of rigidity to rules of one

organization forcing another to its standards can interfere with safe firearm handling

concerns. Safetyrulesmustbeformattedtotheintendeduse.

Example 2. To receive a concealed firearm permit in many locales, one must

take some type of training. Paul Paradis provides this training in a course that is

approximately 20 hours long. Under current Colorado state law, if a military per-

son/retiree can show training qualification within a certain time period, he or she

is exempted from having to take more training. Many soldiers are not trained with

handguns in the military, and, although they may have carried and used a handgun,

they lack the credentials to forego the training. They believe that the military taught

them everything they needed to know about firearms. Unfortunately, many of them

received minimal training and forgot much of it years later. Military training, such

as on taking out a perceived threat, will be in conflict with civilian law of only

using deadly force when there is a direct reasonable threat to life or serious bodily

injury—a much different standard. The military uses violence of action or as much

harm as possible in training for combat. A civilian that uses too much force usually

is considered by authorities a psychopath. The rules are different and, unless the

person is retrained thoroughly and correctly, can be misapplied to the situation at

hand. Recently, a Special Forces sniper came to the author wanting a special class

(shortened from normal standards) to give his fellow snipers an NRA Rifle Instruc-

tors rating. He believed that they did not have to go through all of the NRA training

because they all were trained experts. The author explained that although they had

better-than-average training in marksmanship, the course was not about training

snipers. Rather, the course was training novice shooters in basic skills such as safety.

To illustrate the point the author asked, “What is the first thing you do when you pick

up a gun?” To which the would-be instructor replied, “Check and see if it is loaded,”

picking up a rifle and pointing it at the author while he opened the action. The author

moved the barrel to a safe direction and explained that the action to take first is “to

find a safe direction and then point the firearm in that safe direction, insuring that

it continues to remain safe (i.e., checking to insure that no one inadvertently moves

into the danger area in front of the muzzle). Combat skills for gun handling and use

do not completely translate into civilian skills. Unfortunately, the government does

not retrain its soldiers for civilian life from the combat mentality for weapon use.

COMPARISON OF NRA SAFETY RULES WITH THOSE OF OTHER ORGANIZATIONS

Let’s address the current NRA safety rules and compare them with other organiza-

tions’ rules. In the past, the NRA emphasized the Golden Rule of firearms safety.

Safety Rules 129

Basically it was to “treat all guns as if they are loaded.” It is unknown why in the cur-rent literature this rule has been downgraded. The chapter author Paradis suggests that it should be emphasized regardless of the area of use. Too many times we have heard “I thought it was unloaded” after an incident in which someone was injured or killed after pulling the trigger, intentionally or not. Firearms are mechanical devices that can fail due to manufacturer defect, incorrect repair or modification, and normal

wear. These are not thinking devices, so the holder of the firearm must think for it.

We believe that whether one is pro- or anti-firearm, this very general basic rule, if

ingrained in all, would prevent many lost lives and injuries.

The NRA breaks its 10 rules down into two categories: three rules of safe fire-

arm handling and eight rules of safe firearm use and storage (NRA, 2004a, 2004b).

Usually these rules are in poster form in bold lettering as catchphrases. Students are

encouraged to commit the main phrase of each rule to memory. The current NRA

manuals usually offer brief accompanying information to complement each rule.

THREE NRA RULES OF SAFE FIREARM HANDLING

Always Keep the Gun Pointed in a Safe Direction

The complexity of procedures begins right here: What is a safe direction? How do

you keep the gun pointed in a safe direction? No instructor is fully sure of his stu-

dent’s knowledge or ability to learn and retain the training. The NRA has in its basic

pistol marksmanship class a practical (hands-on) exercise in which the student must

correctly pick up a firearm and open the action to insure that it is unloaded while,

at the same time, controlling the muzzle of the firearm. This exercise is done with

multiple firearm actions in different configurations (hammer down, hammer cocked,

magazine in or out, and so forth). Current basic NRA training uses the catch words

TOTAL PARTICIPANT INVOLVEMENT and takes a multiple sense (hearing, see-

ing, touching) approach to training. Although the first safety rule is important, it

must coincide with active hands-on practice—both physical and mental. This rule

needs manual practice to be remembered and followed correctly.

Always Keep Your Finger Off of the Trigger Until Ready to Shoot

The current pistol manual also states “When holding a gun, a person has a natural ten-

dency to place the index finger on the trigger. Don’t do it! Instead, while pointing the

gun in a safe direction, rest your finger along the side of the gun. Never touch the trig-

ger until actually ready to fire the gun.” This second rule is weak in that it emphasizes

not putting your finger on the trigger in bold poster print (i.e., the main phrase) but

emphasizes keeping the finger out of the trigger guard only in subsequent statements.

Unfortunately, students tend to remember only the catchphrase part of the rule unless

it constantly is enforced by practice. A significant factor relative to finger placement

is the startle reflex, discussed in Chapter 2. A common example is that one’s spouse is

away and the remaining person hears someone in the house. She or he retrieves a fire-

arm and makes his or her way out to determine what is going on. Suddenly, a cat’s tail

or a child’s toy is stepped on, or worse, a person is confronted while turning a corner.

This was not the intruder feared, but the other spouse returning earlier than expected.


Finger muscles involuntarily react, a trigger is squeezed, and there is another inad-vertent death. With any of these scenarios, the chance of a shot being fired is greatly

increased by the trigger finger not being outside of the trigger guard. If the rule were

changed to “Alwayskeepyourfingeroutsideofthetriggerguarduntilreadyto

shoot,”it would likely be remembered and practiced more often.

Always Keep the Gun Unloaded Until Ready to Use

Students are encouraged to obey the first two rules and “engage the mechanical safety

if possible; if possible, remove the ammunition source (magazine or ammunition

from magazine tube), open the action, visually and physically inspect the chamber(s)

and magazine area, which should be clear of ammunition, and leave the action open

with the mechanical safety on. If you do not know how to open the action or inspect

the chamber(s), leave alone and get help from someone who does” (NRA, 2004). One

of the first questions to ask is what is meant by the term use? For example, a self-

defense situation is one in which a gun typically would be kept loaded. Secondly,

how does one know who is a knowledgeable person? In their attempt to make them

safe, even police officers have been known to inadvertently fire firearms with which

they are unfamiliar. Sometimes, gun collections end up with family members who

have little knowledge of safe handling practices. The authors recommend contacting

gunsmiths for guidance when encountering guns with which they are not familiar.

Firearms, especially older firearms, may have mechanical features that are not user

friendly or obvious to the average person, but would be to a professional gunsmith.

COMPLETE VERSUS ABBREVIATED RULES

It is important to understand that regardless of what rules are put in place, posters

showing abbreviated rules often are in the classrooms and ranges. Students in for-

mal training typically are exposed to information of varying degrees that more fully

explains the abbreviated rules and serves as a reminder. The trainee often forgets the

fine points. When the training is not formal, the fine points often are left out, and only

the abbreviated rules are discussed, if anything is discussed at all, and only a subset

of them may be covered. This situation is common in father/child, spouse/spouse, and

employer/employee type training. Often, training is not professional and only abbrevi-

ated information is passed on, if any. The result is that, if anything, only the abbreviated

rules are remembered—and then, only those to which the learner was well exposed.

NRA EIGHT RULES OF SAFE FIREARM USE AND STORAGE

The next eight rules recommended by the NRA are as follows (NRA, 2000a, 2000b)

Know Your Target and What Is Beyond

Every year, hunters mistake other hunters for game animals, and would-be protec-

tors shoot mirrors in their homes. It is important to emphasize target recognition,

when to shoot, and whom you might be endangering when you do shoot. The power

of ammunition often is unrecognized. Manufacturers of even low-powered 22LR

Safety Rules 131

(long rifle) ammunition post warnings of danger of injury or death at 1 1/2 miles; most types of ammunition can go even farther. Unfortunately, television and movies are where most gun handlers get their experience with firearms. The good guy turns

over the cheap bar table and is able to stop the onslaught of machine gun bullets,

but only in the movies and only because it was written into the script. The reality of

distance and penetration often are unrecognized and understated.

Know How to Use the Gun Safely

The NRA recommends learning the basic operation, parts, safety features, how to

open and close the action, and how to load and unload the firearm. Firearm owners

also are cautioned to remember that the safety on the firearm is not foolproof. Like

any other machine, it can malfunction. If manufacturers had called safeties safers,

perhaps many injuries and deaths might not have occurred from the belief that a

safety made a firearm safe.

Be Sure the Gun Is Safe to Operate

Many modern firearms come with good, clear, easy-to-understand instructions—but

many do not. Many military and other surplus firearms come into the country with

no manuals at all. It often is impossible to determine whether or not a firearm is

functional by its outward appearance. Too often, the selling point is price and not

reliability or safety. Inexpensive does not always mean unreliable, nor does expen-

sive mean that it will be functional. Qualified gunsmiths are the persons to consult

about the quality and safety of any given firearm. It also is important to remember

that like any other machine, a firearm needs maintenance and cleaning as specified

by the manufacturer. With discontinued or older firearms, that information may not

be available. Parts for repair may be nonexistent as well.

Use Only the Correct Ammunition for Your Gun

Although this is easy to say, often it is not as easy to accomplish. Two main difficul-

ties are ammunitions that have similar-sounding names but are totally different, and

shooters who are handling, or have in their vicinity, ammunitions that are different.

Often shooters have obsolete or discontinued firearms that may not be marked with

the basic caliber information. With the great influx of surplus military firearms and

war trophies, which typically are not inscribed with ammunition designations, the

problems are exacerbated. Further complicating the correct ammunition problem

are firearms that are altered by replacing the standard barrel or rechambering the

firearm to a different caliber—and not marking the firearm as altered. Chapter 8

on ammunition provides more technical information on this subject. Qualified gun-

smiths are again the single best source for determining correct ammunition and

gun combinations. Gunsmiths typically research the firearm, cast the chambers,

and often test-fire the firearm by means of mechanical firing devices to insure that

the gun and ammunition combination is safe. Because of the cost of these proce-

dures, many shooters take chances and guess—too often ending in eventual dreadful

results. Firearms that have been through fires or suffer from metal fatigue often look


like they will hold up, and may for a few rounds, only to catastrophically disas-semble later in the shooter’s hands.

When talking about ammunition, it is important to understand that there are multiple sources. The four most common source groups are: current commercially manufactured, commercially reloaded, shooter reloaded, and surplus. Each ammu-nition source group can have its own inherent problems that are not visible. Ammu-nition reloading is a practice in which the empty casing that is left after firing has

a new primer, powder charge, and projectile installed. This can reduce the cost of

ammunition. Unfortunately many ammunition users take chances with their fingers,

faces, and lives to save a few dollars. Although ammunition reloading is practiced by

millions, a small mistake can have catastrophic results. Many firearms are destroyed

and injuries sustained by home reloaders who make a mistake in estimating the cor-

rect powder charge. The reliability of ammunition often is determined by storage

conditions; this affects the ammunition internally and is not always outwardly vis-

ible. Because many older types of ammunition have corrosive components and lack

correct storage, they may break down internally. By all outward appearances it may

look usable but actually is not, and it may not perform as designed. Current major

manufacturers are the best source for ammunition that is problem free.

In Figure 7.1, the top right handgun is a modern Smith & Wesson model 29 that

had 44 magnum reloads with incorrect powder in the ammunition. The bottom right

is an older Rossi .38 Special firearm in which the father-in-law provided HOT (over-

charged) ammunition to his son-in-law. Fortunately, both shooters received relatively

minor injuries—a testament to how modern firearms are designed to blow out and

away from the shooter during catastrophic failures. Unfortunately, the daughter/wife

lost the tip of her nose while standing to the side of the firearm when it failed.

Wear Eye and Ear Protection as Appropriate

For the average shooter, both eye and ear protection are an inconvenience; they are

costly and often uncomfortable. Too often, only after a disaster does the value of

safety gear become obvious. Often, the task at hand (e.g., military combat, police

FIGURE 7.1. Two damaged handguns from improper ammunition.

Safety Rules 133

confrontations, civilian self-defense, hunting) does not lend itself to using safety equipment. There also is an apparent mistaken belief that one should practice for reality without safety devices—that you should “practice as you will do.” Although it is unlikely that an enemy or intruder will allow you to have the time to don safety equipment, the great majority of shots fired will be in practice. The eyes and ears

are delicate organs that are easily damaged. Thanks to modern medical science, we

understand more about how they are damaged and how to protect them.

Theneedforeyeprotection.Although most persons understand how vulner-

able the eyes are during a catastrophic failure, there appears to be less regard for the

residues from shooting a firearm. Molten metals cast off from the ignition process,

burning and unburnt powder and gasses, and splatter ricocheting back from targets

can, and have, caused serious injuries. Shell casings ejected from semiautomatics are

another source of potential injury. The authors recommend using safety glasses with

side shields. Safety glasses should meet ANSI Z 87.1. A baseball cap also provides

protection to the eyes by providing a roof over the safety glasses. A cap also has a

side benefit: When it is worn, less light hits the eyes, so the pupils will dilate, thus

enabling the shooter to see the sights better.

Hearing,deafness,andtheimportanceofearprotection.Many, if not most,

shooters underrate the importance of ear protection. Sound is created by vibrations

that create sinusoidal or sine waves, which vary in frequency, or cycles per second

or Hz, and intensity, or sound pressure, measured in decibels (db). Sound enters the

ear opening, passing through the auditory canal to the eardrum. Sound vibrates the

eardrum, which connects to the ossicles, a chain of three small bones in the middle

ear commonly known as the hammer, anvil, and stirrup, which acts as an acoustical

amplifier, connecting to the oval window at the beginning of a coiled-shaped struc-

ture known as the cochlea. The cochlea, or inner ear, consists of three chambers:

the vestibular and tympanic canals and the cochlear duct that separates them all by

a small hole at the apex (inner end of the coil) called the helicotrema. The basilar

membrane separates the cochlear duct from the tympanic canal. It is narrower and

stiffer nearer the oval window and becomes more flexible toward the helicotrema.

The organ of corti sits on the basilar membrane. It contains two groups of hair cells,

or cilia, that project into the cochlear fluid in the cochlear duct. Motion of the fluid,

caused by the vibration of the oval window, causes the cilia to bend, which initiates

a neural signal that is transmitted to the auditory cortex of the brain, which we then

experience as sound. The cilia are sensitive to different frequencies, depending on

where they sit on the organ of corti. It also is believed that the vibration of the basilar

membrane itself provides low-frequency sound signals. Continuous exposure to

noiseabove85dbandtofrequentloudimpactorimpulsenoise,suchasencoun-

teredatgunranges,willeventuallycausepermanentnervedamagetotheinner

ear,resulting indegradedhearingand,not infrequently, tinnitus (aconstant

high-frequencyringingintheear).Exposureoveraperiodofyearswillgradu-

allyincreasethefrequency,breadth,andseverityofthehearingloss (Sanders &

McCormick, 1993). We also receive sound vibrations by way of the mastoid bone,

which lies behind the ear. Therefore, both the ear and the mastoid bone must be pro-

tected from loud noise. Earmuff-type protectors provide protection to the mastoid

bone that earplugs will not, as well as providing a shield to the ear itself.


It is well known in the human factors/ergonomics community that people will only use safety precautions for which they understand and appreciate the need. Providing this understanding is an essential part of handgun safety training. The authors strongly assert that students/shooters only use safety precautions for which they understand the need.

Never Use Alcohol or Drugs Before or While Shooting

There have been volumes written and taught on illicit drugs and alcohol and their detrimental physiological, cognitive, and emotional effects on humans. As related to handling a firearm and unintentional shooting incidents, the details and importance

of these effects are described in Chapter 2.

Store Guns So They Are Not Accessible to Unauthorized Persons

The safe storage of firearms is dictated by a number of factors and is covered in

Chapter 8. Just as training with firearms is important, training on ways to store fire-

arms safely also is important.

Be Aware That Certain Types of Guns and Many Shooting

Activities Require Additional Safety Precautions

This catchall rule is relatively self-explanatory and makes sense to those who have

common sense. Unfortunately, not all firearm handlers realize their responsibilities

to learn the rules. Over the years, mostly due to lawsuits, ranges and firearm groups

have required mandatory training to use their facilities or participate in shooting

events. This type of social shooting helps to prevent accidents in that the training is

continual and inappropriate actions are penalized. Unfortunately, many otherwise

interested gun owners do not have the facilities or financial resources to participate.

Although there is considerable merit to the NRA safety program rules, another

source of information is the manufacturers of firearms. The information that the man-

ufacturers provide can run the gamut from a little to a lot, poorly written to well writ-

ten, and from overly simplistic to overly complicated. Firearms can last for decades,

if not centuries. Information on firearms that have been discontinued or from compa-

nies that have gone out of business often is nonexistent. Knowledge of maintenance

procedures has been lost as well. Millions of firearms are still circulating in society

that have no manuals or safety information associated with them. The government,

NRA, and various collector organizations have volumes of information on specific

discontinued models. Rarely is this information easily available to the general public.

However, manufacturers are putting their manuals on their Web sites; some offer

information on discontinued models, and some even publish their own lists of safety

rules (see Remington, for example). Unfortunately, some advice on the Internet is not

complete or reliable. But, information is not only available from the manufacturers

Web sites; blogs and Internet discussion groups on handguns are numerous.

When one does read the manuals that are present with current firearms, the

reader is reminded of the basic, abbreviated NRA rules. Unfortunately, the neces-

sary additional explanations often are not present.

135

8 Means of Preventing

Access to Home

Protection Handguns

INTRODUCTION

An important goal for human factors professionals and others interested generally with safety of handguns is to restrict access to them, especially for young children, teens, or mentally handicapped persons. One of the most effective ways to prevent unintentional shootings of and by children is to deny unauthorized access to hand-guns (Teret & Culross, 2002). In this chapter, there is an emphasis on the protection of young people; however, security measures to protect young persons from inadvertent shootings apply to adult safety as well. It is obvious that no one, young or old, desires to be involved in an inadvertent shooting—either as the victim or the weapon holder. We describe the current devices to safeguard handgun use and explore some of the new technology under development, which potentially can be used for this purpose.

THE PROBLEM

To illustrate the problem, one of the authors (Hal Hendrick) was asked to evaluate a case in which an adolescent boy, whom we call Bill, took his younger sister into their parent’s bedroom to show her their daddy’s semiautomatic, located in the drawer of his bedside table. Bill opened the drawer and saw the handgun and the clip beside it. He picked up the semiautomatic with the clip out, assumed the gun was not loaded, playfully pointed the gun at his sister, and pulled the trigger. Sadly, the chambered bullet killed his little sister.

As reflected in this example, the problem has at least two facets: (a) unsecured handguns kept in the home, and (b) unrealistic parental perceptions about children and gun safety. Underlying both is the issue of a lack of formal handgun safety train-ing, which is covered in Chapter 9.

HANDGUNS KEPT UNSECURED IN THE HOME

Stevens et al. (2001) analyzed self-report questionnaires from 3,145 ten-to twelve-year-old children and 3,145 parents concerning guns in their households. Results showed that 32% of the children lived in households with guns, and children in 54% of these households had access to unlocked guns in their home. These results are consistent with the national average of 35% of households having one or more guns (Flanagan, 1997) and with another study (Senturia, Christoffel, & Donovan, 1996),


which showed that 61% of households with guns reported keeping them unlocked. In an Oregon survey study of 6,202 adults, 10% lived in households where guns were kept not only unlocked, but loaded, including 6.2%of all households with children, which projects to 40,000 Oregon children being exposed to loaded firearms in their

homes (Nelson et al., 1996).An August 26, 1996, New York Times article on Saf-T-

Lock (see the discussion of Saf-T-Lock that follows later) notes that the American

Medical Association estimates that over one million children 14 and younger have

access to firearms at home. The authors have been involved as expert witnesses in

several unintentional fatal shooting cases that would have been avoided if the parents

of the young teenagers had not kept a loaded handgun unsecured in one of their bed-

room drawers or other areas accessible to youth in the household. In these cases, the

teenagers involved were charged with first- or second-degree murder.

UNREALISTIC PARENTAL PERCEPTIONS ABOUT CHILDREN AND GUNS

In a questionnaire survey of 400 parents bringing their children to four ambulatory

centers, 28% believed their child (under 12) could be trusted with a loaded gun.

Fifty-eight percent of those owning guns stored their guns either loaded or unlocked.

The study concluded that the majority of parents underestimate the risk of injury

from handguns to their children (Farah, Simon, & Kellerman, 1999).

In addition, author Paul Paradis has found parents to underestimate the risk of

injury from the inadvertent use of handguns by their own children. He also notes

from his observations that there appears to be a difference in expectations of parents

by geographical area. He has observed distinct differences between those in rural

versus urban environments. It is not unusual in rural rancher and farm families to

have firearms readily available for personal protection—because law enforcement

response times can be lengthy—and for use to protect livestock from predators.

Often, target shooting is both a family as well as a community event, and safety is

instilled at a young age. Training tends to start as the youths show interest. Mechan-

icaldevices that slow theresponse timeormakeafirearmunusable forany

familymemberarelookedatwithdistasteinfavorofeducationandpractice.

In addition to parents, programs such as 4H provide additional learning opportuni-

ties for children in rural communities, and firearms are not perceived by the gen-

eral community as a threat. In contrast, in a large metropolitan area, the perceived

need for self-defense is present among many, but educational opportunities to learn

safe practices, including safe storage of firearms, may be limited in various cities.

Though there are circumstances in which young persons learn to respect and to take

care with handguns, those circumstances are not as common in large cities.

PREVENTING UNAUTHORIZED ACCESS

In the home situation, preventing unauthorized access to handguns can be accom-

plished by two different methods: (a) external restraints and (b) handgun internal

personalized access systems.

Means of Preventing Access to Home Protection Handguns 137

EXTERNAL RESTRAINTS

External measures consist of two primary types: (a) trigger locks, and (b) lock boxes or other locking devices that prevent casual access to the handgun.

TriggerLocks.These devices encase the trigger portion of the handgun and must be unlocked by a key, combination lock, or keypad in order to shoot the firearm

(see Figure 8.1). The advantage of trigger locks is that they are low-tech, relatively

inexpensive devices. A major disadvantage is that one could lose or misplace the key

or forget the combination lock in a crisis situation. A second major disadvantage is

that children are notoriously skillful at eventually discovering the location of keys or

gaining access to combination codes, and thus gaining entry to the enticing forbid-

den fruit when parents are not around. A third disadvantage is that it takes time to

set the combination or find and use the key—a problem that can be critical at night

in a situation in which you do not want to turn on a light, such as when you suspect

an unauthorized person has entered the house.

LockBoxesandGunVaults.Lock boxes and gun vaults designed for storing

handguns and ammunition are readily available commercially. Like trigger locks,

they are designed to be opened by key, combination lock, or keypad. In some cases, a

padlock can be used. Their major advantages and disadvantages are similar to those

for trigger locks. Other variations, such as lockable gun cabinets or gun racks, also

are available commercially.

A well-designed study of unintentional firearm events among those 20 years of

age or younger, identified by medical examiner and coroner offices in 37 counties in

Washington, Oregon, and Missouri, and five trauma centers in Seattle, Spokane, and

Tacoma, Washington, and Kansas City, Missouri, was carried out by Crossman et

al. (2005). Even after correcting for contaminating factors, significantly fewer events

Upper left-hand corner electronic keypad system on the firearmand to the right of the firearm mechanical (keyed) trigger lock

FIGURE 8.1. Trigger lock.


occurred among children from homes where the firearms were kept locked up than

among those from households where the firearms were not.

PERSONALIZED ACCESS SYSTEMS

An even more effective way of preventing unauthorized use of a handgun is to design

it so that it will fire only when used by an authorized user. For example, in one study

of 117 unintentional and undetermined firearm deaths, 37% were classified as pre-

ventable by a personalized gun (Vernick et al., 2003).

The best-known personalized handgun methods are (a) magnetic, (b) magnetic/

electric, (c) grip cocking, (d) keypad entry, (e) key-lock, (f) radio frequency identi-

fication devices (RFID), (g) grip pattern recognition, (h) fingerprint recognition, (i)

wireless personal identification smart cards, and (j) voice recognition. The magnetic,

grip cocking, keypad entry, and key-lock systems have been incorporated into some

handguns on a limited basis, including through retrofit kits. The other systems noted

are still in the prototype or development stage, with some showing real promise.

Magnetic. Perhaps the most advantageous of the already developed internal

devices is the magnetic type. This system requires the intended handgun user to wear

a ring with a tiny magnet embedded in the bottom. The system operates by a flag-

shaped steel block, which blocks the internal firing mechanism until close proximity

of the magnetic ring rotates the block, thus enabling the trigger to depress. This hap-

pens when the person grips the gun with the hand having the ring. The system was

patented by Joe Smith in 1975 and was adopted by several law enforcement depart-

ments. A current version is produced and sold by Tarnhelm, a New Hampshire-based

firm. The obvious advantages are that no one else can fire the handgun except the

one wearing the ring and that it is a passive device, requiring no additional action

on the part of the gun handler. The magnetic system is designed such that ordinary

magnets cannot also operate the device. The major disadvantage is that one must

wear the ring (although the magnet can be embedded in any ring the person nor-

mally wears). Also, one cannot use metal grips on the gun handle that will block the

magnet’s pull (most grips can readily be replaced by nonmetallic ones). Izumi (1996)

personally found use of his own modified handgun particularly valuable while his

sons were young and could not appreciate the potential danger.

Magnetic/Electric.Also known as a solenoid use limitation device, it involves

a magnetically activated solenoid, which requires a power source. As with the mag-

netic type, a magnetic ring is worn by the user. When the user grips the gun, the ring

magnet activates the solenoid via electronic encoding, which unblocks the firing

mechanism. A custom grip is a part of the system. Its advantages and disadvantages

are similar to the magnetic type. However, it has the additional disadvantages of

being more complex, and the power source eventually will go dead (which might

happen at a critical time).

GripCocking.Grip cocking is not a true personalized access system; rather, it

is designed to prevent young children from operating the firearm. With this type of

system, in order to fire the handgun, the operator must exert considerable pressure

on the grip to enable the gun to fire. The grip pressure level is set high enough that

young children cannot activate the handgun (approximately 10 pounds), which is its


major advantage. Also, persons unfamiliar with the system would not likely grip the gun tightly enough to enable it to fire. However, small or otherwise weak adult users

also might not be able to fire the handgun or be able to fire it accurately. Another dis-

advantage is that older adolescents and teenagers do have sufficient strength to enable

the firing mechanism.

Grip cocking is the oldest of the systems for preventing young children from

being able to fire a handgun. It was developed by Smith & Wesson and initially

incorporated into its .38 caliber Safety Hammerless in 1888 and in the .32 caliber

model two years later. Smith & Wesson manufactured more than 500,000 guns with

grip safeties between 1886 and 1940, and these were known as the company’s New

Departure models. Smith & Wesson moved away from producing these models when

it turned to focusing on providing guns for British soldiers early in World War II

(Teret & Culross, 2002).

KeypadEntry.Perhaps the best known of these types is the Florida-based Saf-T-

Lock system, developed by Frank Brooks. A three-digit keypad is embedded on the

side of the handgun. The user installs his or her personalization code. To enable the

gun to be fired, the user enters the preset three-digit code by pressing the appropriate

keys. Each key is pressed repeatedly until the desired digit shows (e.g., three presses

for a 3, etc.). For quick response, two of the keys can be preset, thus leaving only one

of the keys to press to enable the gun to fire). According to a Miami Herald March 11,

1996, article on the Saf-T-Lock system, at that time existing guns could be modified

for about $120 to $150.The major advantage of the system is that anyone not know-

ing the code cannot readily enable the system. In addition, it is fully mechanical, so

no power source is required (which might go dead at a critical time). As with keypad

lock boxes, major disadvantages are that one might forget the code, or others, such

as children in the family, might eventually discover the code. An advantage over lock

boxes is that one step is saved—that of having to also take the handgun out of the box

once it is opened. Perhaps a more important advantage is that someone forcefully

Grip

Cylinder

Trigger

Trigger Guard

SafetyLever

Front Sight Rear Sight

Barrel

Barrel Catch(Release)

Muzzle

Butt

Prawl

FIGURE 8.2. Smith & Wesson hammerless safety.


taking the gun away from the intended user before the full code is entered would not be able to fire it. A February 1997 Combat Handguns article on Saf-T-Loc concluded

that the system has good suitability for use on home defense handguns.

Key-LockingSystems.Several handgun manufacturers, (e.g., Steyr of Austria

and Taurus of Brazil) offer key-locking firing mechanisms on some models of their

semiautomatic pistols and revolvers. The key-locking system adds little to the cost

of the same handgun without the system. The obvious advantage is that only persons

with the key can enable the handgun to fire. The disadvantages are that the key might

become misplaced, or not be readily available when needed, and that children might

find the key and use it.

Radio Frequency Identification (RFID). Handguns equipped with these

devices are called smart guns. One such system is produced by Smart Links, Inc. of

Oakland, California. An encoded close-range radio wave from a watch-like wrist-

band or other emitter worn by the user is received by a microchip inside the gun’s

grip, which causes a tiny aerospace stepper motor to activate the firing mechanism.

Sandia laboratories, which have evaluated the various internal systems described

earlier, gave this technology its highest rating. However, there still are drawbacks:

RF links add weight and cost; battery maintenance, status indicators, and reliabil-

ity are significant issues; and it would be difficult to modify current guns. Some

manufacturers believe the practical solution is to incorporate RFID technology into

a true electronic gun—an advancement that is being considered or already is under

development by gun manufacturers (Wirsbinski, 2001).

Grip-PatternRecognition.A smart gun system under development is one that

recognizes the unique grip pattern of the intended user. One such system utilizes a

pressure sensor consisting of 44 X 44 piezoresistive elements. Initial results indi-

cate that it is a feasible system, but it does result in some false rejections and false

acceptances, so more refinement is needed (Kauffman, Bazen, Gerez, & Veldhuis,

2003). Kauffman et al. (2003) note that this system (and other smart gun systems)

interests police departments in the United States and elsewhere because they have to

become involved in risky public situations. In fact, about 8% of police officers killed

in shooting incidents are killed by their own firearm (Federal Bureau of Investiga-

tion, 2001).

FingerprintRecognition.Computer chips already are on the market for use in

other products to scan fingerprints. Soon these chips will be made durable enough to

withstand the trauma of gunfire and thus can be incorporated into guns (D’Agnese,

1999). Already, a personalized holster is on the market that keeps the gun locked in

the holster unless a device reads the fingerprint of an authorized user (Smith, 2001).

SmartCard.Wikipediadescribes the smart card is an intelligent device with a

computer chip that looks much like a traditional credit card. In effect, it is a credit

card with a brain. It is capable of storing a great deal of information in its internal

memory, including personal information, digital signatures, and biometrics—such

as fingerprints, retina scans, voice scans, and DNA—medical and prescription infor-

mation, buying preferences, and so forth. Smart cards can intelligently process infor-

mation when introduced to a reader. There are two different types of smart cards,

contact and contactless. The contact smart card requires one to physically insert it

into a reader, whereas a contactless type requires only close proximity to a reader,


as the card has a low power transmitter built into it. A contactless smart card reader communicates with the contactless card across distances of about 10 cm or less via a radio frequency signal. This contactless technology should eventually be a feasible means for personalizing handguns. It is another type of radio frequency identifica-

tion system (Finkenzeller, 2003).

Voice Recognition. Voice recognition technology is well developed and may

eventually be incorporated as a smart gun personal identification method.

143

9 Training

INTRODUCTION

Hopefully, the human factors and ergonomic deficiencies and lack of standardization

of handgun features affecting safety, along with protective devices to prevent inad-

vertent firing, will be addressed in the design of future firearms. However, except for

some limited retrofits, ergonomic safety problems with the design of the thousands

of handguns already in use will remain unresolved. Given this reality, the only prac-

tical solution is to resort to the human factors/ergonomics technology of training.

Although the right to own firearms in the United States is jealously guarded,

the necessity for a comparable level of training is not as visible. It is sad but true to

note that no training is required in most states to purchase a handgun. This state of

affairs is highly regrettable, especially considering how effective a relatively short

training program can be for instilling safe handling practices. From the authors’ col-

lective experiences (particularly those of Paul Paradis) in investigating hundreds of

accidental shootings, almost all were found to have occurred with persons who either

had never taken a formal firearm safety course or had taken the course many years

ago and it consisted of questionable content. Yet, where a handgun safety course is

required by the community in order to obtain a concealed weapon permit, and that

training is sound in content and taught by highly trained personnel, there is evidence

that it can be highly effective in reducing the incidents of accidental deaths. For

example, Paul has provided handgun safety training to thousands of persons. To

his knowledge, not one person who has followed his safety procedures has been

involved in an accidental shooting with injuries or death.

In light of the previously mentioned, we believe that implementing a handgun

safety training requirement in order to carry a concealed weapon could greatly reduce

the number of accidental shootings—particularly if the quality of the training is high.

Unfortunately, improvement still is needed with respect to both training content and

training instruction, which is addressed later in this chapter. Skilled and effective

training is essential to reduce inadvertent and unintentional deaths from handguns.

WHY TRAINING IS ESSENTIAL

COMMON MISTAKES OF UNTRAINED PERSONS

From the first author’s observation of the students’ behaviors during the initial phases

of two of Paul Paradis’s handgun safety courses, well over 80% of the participants

committed all three of the following safety errors with a handgun. When authors Hal

Hendrick and Richard Hornick first took Paul’s course, they made the same mistakes

as well.


Failure to note where the handgun was pointed. Virtually all of the beginning students committed this error, not once but several times. The result was their point-ing the handgun at other persons or at locations where other, unobserved persons could be located (e.g., behind the wall in an adjacent room, in the room above the training room, etc.).

Failure to properly check to insure that there is no cartridge in the chamber. Beginning students invariably did not positively insure that their semiautomatic was unloaded by actually inspecting the chamber to insure that it did not contain a car-tridge, or fully checking each chamber of the cylinder of their revolver. Given this fact, not surprisingly, perhaps the most frequent explanation one hears when there is an unintentional shooting by an untrained person is“I didn’t know the gun was loaded.”A related problem with revolvers for beginning students is that they get con-fused as to which is the next position on the cylinder to fire. There have been cases in

which the shooter has unintentionally fired a revolver, not realizing that the cylinder

was going to rotate to a loaded chamber when the trigger was pulled.

Finger on the trigger. Because it is the natural and comfortable location to place

one’s index finger when gripping a handgun, beginning students invariably put it on

the trigger. A key safety principle is to keep one’s finger outside of the trigger guard

until ready to actually fire the handgun. By the end of training the students all were

keenly aware of this safety procedure.

Other common mistakes.In addition, the beginning students committed numer-

ous other errors, such as improper body positioning and lack of balance during simu-

lated shooting practice, holding the handgun too tightly, jerking the trigger, placing

the trigger finger improperly, not sighting properly, and anticipating the recoil, all of

which can result in inaccurate firing or unintentional discharge of the handgun.

By the time they had completed the training course the students had largely

corrected all of the previously mentioned errors and were keenly aware of proper

handgun operation and safety procedures.

One of the most common uses for handguns is self-defense. Currently, 38 states

allow the carrying of a concealed handgun. When one looks at the tactical/judgment

mistakes that often are made, resulting in innocent bystanders being injured—as well

as the firearms handlers themselves—the significance of appropriate self-defense

training previously mentioned and beyond basic marksmanship skills is obvious.

The human factors cost should not only be measured in injury and death alone, but

also by the loss of an otherwise productive citizen to society when training issues

result in negligent/reckless criminal actions. Simply put, the ability to load and pull

the trigger and generally put the projectile where it was intended to go does not make

a qualified firearms handler.

IMPROPER LEARNING FROM TV AND MOVIES

Another reason handgun safety training is so critical is that most of us have been

exposed to unsafe procedures from TV and movies because we were young and

impressionable children. For example, TV shows and movies about cops and robbers

often depict both the good guys and bad guys carrying their firearms with their finger

on the trigger and pointed in unsafe directions, as well as many other incorrect/unsafe

Training 145

actions—not to mention in cartoons, such as Elmer Fudd going hunting for a well-known rabbit. These unsafe depictions are well ingrained in our psyche by the time we reach our teenage years. The movie and TV industries would do us all a great service if they would portray safe handling of firearms. We are convinced that proper

handling of firearms can be done without detracting from the drama of the scenes.

IMPROPER LEARNING FROM OTHER UNTRAINED PERSONS

Still another problem is that the only training many children and teenagers get is

from parents or friends who themselves have had no formal handgun safety train-

ing. Thus, we have the blind teaching the blind. Similarly, people such as police and

military have training on a limited number of firearms and for specific purposes. As

such, they do not have sufficient knowledge to train all people with all guns. As one

police officer wrote to Mr. Paradis, “Cops are dangerous because we’re supposed to

know how to deal with guns, but the training we receive only tells us how to use the

guns we’re issued. This is a problem when encountering other guns on the street.”

WHAT LEGALLY CONSTITUTES ADEQUATE

TRAINING VERSUS TRUE ADEQUACY

When there actually are legal requirements for handgun training, there often is a discon-

nect between what legally constitutes adequate training versus what truly is adequate.

For example, to its credit, El Paso County, Colorado, when it instituted a con-

cealed handgun permit system, required formal handgun safety training in order

to carry a concealed weapon. However, current or previous military service hand-

gun qualification is considered appropriate and adequate training for meeting this

concealed weapon requirement. Yet the direction of training in the military carries

an entirely different orientation—aggressive combat versus suburban self-defense—

two totally different mindsets. In El Paso County, following heavy lobbying by the

NRA and other gun rights activists, Colorado’s criteria were altered in 2003. The

new wording is so vague that virtually anything someone puts together can be called

a handgun course. Currently, there are courses being taught as evidence of meeting

the firearm training requirement that are only 3 hours in duration and do not include

firing a firearm. Because of the vagueness of the law, hypothetically, it is possible for

someone to have a 1/2-hour course to satisfy the requirement.

The current Colorado law reads as follows.

18-12—205.5 “HANDGUN TRAINING CLASS” MEANS: (a) LAW ENFORCE-

MENT TRAINING FIREARMS SAFETY COURSE (b) A FIREARMS SAFETY

COURSE OFFERED BY A LAW ENFORCEMENT AGENCY, AN INSTITUTION

OR ORGANIZATION OR FIREARMS TRAINING SCHOOL, THAT IS OPEN

TO THE GENERAL PUBLIC AND IS TAUGHT BY A CERTIFIED INSTRUC-

TOR: OR (c) A FIREARMS SAFETY COURSE OR CLASS THAT IS OFFERED

AND TAUGHT BY A CERTIFIED INSTRUCTOR. The NRA nonshooting orienta-

tion course appears to be the most common course taught. The NRA does nothing to

formally inform instructors and/or consumers of the inappropriateness of this lesson

for self-defense or concealed carry purposes. In the instructors’ lesson plans from the


NRA (NRA, 1995, PFP-3), it is stated: “Since FIRST Steps orientations are model specific, and teach only the most basic shooting skills, they are not complete ‘courses’

in the traditional sense of the word....For this reason, the orientation encourages par-

ticipants to obtain additional training in an NRA basic Firearm Training Course,

and then take the ‘next step’ by participating in other local activities designed to help

individuals maintain and develop their shooting skills.” As can be seen from this

statement, the NRA contingent lobbying for firearm rights seems to conflict directly

with the more realistic NRA firearm training division.

Another example is the 12-hour hunter safety course, which also is considered

asmeeting the concealed weapon handgun safety training requirement in El Paso

County. Yet these courses typically have less than one hour of weapons training,

and that hour includes rifle, shotgun, handgun, and archery. Although called hunter

safety courses, they address other topics, such as survival skills in the wild, hunter

ethics, animal identification, and so forth, and do not constitute a firearms safety

course. Clearly, these courses only address very basic safety and marksmanship

issues. In the opinion of the authors, hunter course safety criteria fall far short of

what is required for safe use of a handgun intended for self-defense. Accordingly, the

hunters’ safety training certificate should not be treated as a substitute.

In evaluating the adequacy of any prior firearms training for meeting a legal

handgun home defense or concealed weapons training requirement, its content needs

to be evaluated against established criteria for such training. Where that prior train-

ing does not meet the established criteria, it should not be allowed to meet the safety

training requirement.

CURRENT HANDGUN TRAINING PROGRAMS

THE MAJOR HANDGUN SAFETY PROGRAMS

The most widely used basic handgun safety programs in the United States are the

National Rifle Association (NRA) marksmanship programs. There are five NRA

basic handgun safety courses, hereafter called the NRA programs, which are

addressed herein. Additionally the NRA has pistol orientation (introduction) classes

that are nonshooting classes. Because the NRA does not describe these classes as

anything more than orientation, they will not be discussed as training. As identi-

fied by the copyright of their manuals, the NRA courses are the 1959 Basic Pistol

Marksmanship (BPM), replaced by the 1991 Basics of Pistol Shooting (BPS), and

the September 1988 Basics of Personal Protection (BPP), replaced by the Septem-

ber 2000 Personal Protection in the Home (PPIH). A new course, entitled Basics of

Personal Protection Outside the Home (PPOH), is soon to be released. The course

manual, April 2006 NRA Guide to the Basics of Personal Protection Outside the

Home (PPOH), already is published.

The 1959 BPM manual consists of 30 pages and was very inadequate in cover-

age (i.e., you could not read it and understand how to use a handgun). The 1991

BPS course, which replaced the 1959 version, has a 114-page manual that is far

more adequate in its content and explanation. One probably could read this manual

and have a very basic understanding of safe gun handling and marksmanship, as

Training 147

more in-depth explanations were provided throughout the manual. However, this manual was designed for those interested in target shooting, not home protection. The 1988 Basics of Personal Protection was the first NRA course manual dedicated

to marksmanship and self-defense. It consisted of 118 pages and was broad in scope,

but not very detailed. The 1988 course was discontinued when the 2000 Personal

Protection in the Home course was implemented. The 2000 course manual has 219

pagesand is more specific to using a firearm for self-defense in the home. The NRA

expects that a person taking this self-defense course would already have completed

the 1991 basic pistol-shooting course as a prerequisite.

Although all four of these NRA programs have much excellent content, in the

authors’ opinion, there are a number of deficiencies that we believe limit their effec-

tiveness. These include issues of content aswell asmacroergonomic (systems) issues

regarding the overall NRA training system. We address each in turn.

CONTENT ISSUES

The NRA Courses Should Require Trainees to Show Competency With a Single Handgun

Our first concern is that all four NRA courses should require a person to receive

familiarity training with multiple types of handguns (e.g., semiautomatic versus

revolver; single action versus double action) but to show competency with only a

single gun during a given firing course. Currently, the four NRA courses described

earlier address mechanical features of different firearms, but they do not limit the

student to actually learning to fire a single gun in a single training course. To achieve

competency with a given handgun, significant repetition is essential. The NRA

courses do not provide sufficient time for doing this. Further, switching from one

handgun to the other during training can inhibit developing competency because

of negative transfer effects causing confusion and interference. Many students take

training with a firearm, which may or may not be the type of gun the individual

owns. Students have shown up to classes with firearms that had excessive recoil or

required dexterity or strength beyond their ability to operate, often because a car-

ing individual with little knowledge themselves thought that this is what the student

should use. As a minimum, the students should be required to become competent

with the type of firearm that they own (e.g., revolver versus semiautomatic). Ideally,

it should be with their own handgun, which needs to be within their capabilities. In

addition, many persons ownmore than one type of handgun. Students may show up

with the gun that is the easiest for them to handle or use accurately, but not the one

they intend to use with concealed carry. The NRA’s recommendation should be to

ensure that when multiple guns are owned, the training takes place with the gun the

student most likely will actually use. Ideally, the student should be strongly encour-

aged to eventually take training with all guns owned. AsexplainedinChapter3,

theproblemhereisthathandgunsvarygreatlyintheirdesign,safetyfeatures,

andoperation.Consequently,theassumptionthatyoucangeneralizetraining

ononespecifichandguntoothertypesishighlyquestionableatbestandcanbe

downrightdangerous. We believe a home defense handgun-training course needs

to require the trainee to become familiar with a wide variety of gun designs and


types so that the decision of what to own, purchase, or carry is made as a competent decision by the user. In addition, familiarity with a variety of handguns enables the student to understand that one cannot generalize from one to another. From

theauthors’collectiveexperience in investigatingaccidental shootings,many

have involvedassumptions that the characteristicsand safety featuresof the

guninvolvedintheincidentwerethesameasanothergunwithwhichtheper-

sonwasmorefamiliar.Ineffect,negativetransferoftrainingresultedwhenthe

personhandledthenewhandgun.

A good example would be the differences in how one unloads the older Colt single-action type and the newer Ruger single-action type of revolver. Although both revolver types generally appear to be identical on the outside, they are dramatically different in their internal mechanisms. Unloading the older Colt system requires the shooter to pull back on the hammer to a point where the cylinder spins around freely. At this point, the shooter opens a little gate, known as the loading gate, and uses an ejector rod located under the barrel, lining it up with each chamber and pushing out the spent cartridges. There are two problems with this system. One is that on a fully loaded cylinder the firing pin would be resting againstthe primer of the cartridge. If

the hammer received a sharp blow, such as from dropping the gun, the revolver could

easily discharge. The second problem would be when the shooter draws the hammer

back too far, passing the lock notch that would allow for free location of the cylinder,

and thus having to let the hammer back down again manually. To let the hammer

down to the starting position, it must be drawn allthe way back, the trigger must be

pulled, and the hammer must be held by the hammer spur (which is a small piece of

metal) and lowered back into a firing position without allowing enough pressure to

cause a discharge of a cartridge. If the hammer spur slips off of the shooter’s thumb,

the gun will discharge. The newer Ruger system, developed in the 1960s, allows the

shooter to open the loading gate to have the cylinder free-spin. This allows the gun

to be unloaded without handling the fire control portions of the gun (i.e., the hammer

and trigger). Also, if a person were to manipulate the hammer rearward, the loading

gate would lock in place, and there is no notch on which the hammer could catch.

If a person is trained on the Colt system, and then handles a Ruger system revolver

and manipulates the hammer rearward, he or she will not find the notch to lock the

hammer but will have to continue on to the fully cocked position in order to let the

hammer allthe way down again. Any time the hammer is manipulated and a loaded

cartridge is in the firing chamber, there is a potential for discharge.

On the other hand, if a person had his or her training on a Ruger system firearm,

and then switched to a Colt system, one would find that moving the cylinder gate does

not allow one to unloadthe revolverand, typically, one might start probing around to

find out what is wrong, which leads to the potential for an unintentional discharge.

This is further complicated by the fact that one needs to multitask: One task is to

unload the revolver;the second is to be aware of where the muzzleis pointed. As was

pointed out in Chapter 2, humans have a difficult time performing two tasks at once

if both require one’s conscious attention. Inhavingtofocusonmonkeyingaround

tofindoutwhatiswrong,thepersonis likelytoforgettoattendtothemore

criticaltaskofkeepingtherevolverpointedinasafedirection.

Training 149

Of note from a training perspective, the NRA PPIH manual, used for years, only discussed the Colt system and did not even mention the newer Ruger system, although the recall by Ruger has been out for many years. Yet directions for both

could easily be incorporated, thus enhancing user safety. The photographs in this book and DVD are from the recalled gun.

Failure to Teach the Nature of Stress and Its Effects

Asecond serious lack of the NRA programs from a human factors safety standpoint has been the failure to teach the nature of stress and its physiological, perceptual, emotional, and cognitive effects as they relate to use of firearms (see the discussion

of stress and its effects in Chapter 2). The NRA PPIHcourse (2000) does give a brief

description of psychological and physiological reactions to a threatening encounter.

This is very commendable, but it needs to be expanded.

Of course, nothing has been done to address the tens of thousands of persons

trained on past NRA programs who believe themselves to be trained, who never

received even the PPIH content on stress and other pertinent information that would

make their lives with firearms safer. Given that the actual situations in which a per-

son is likely to be using a handgun for self-defense are typically highly stressful,

this knowledge is critical. The authors have been involved in criminal defense cases

where an individual was charged with first-degree murder, yet the evidence points to

the incident having been an inadvertent shooting brought about by the person’s lack

of gun training and the highly stressful nature of the situation.

Conflicting Principles of Pistol Marksmanship Among Courses

The NRA courses are not consistent as to what constitutes the fundamental prin-

ciples of pistol marksmanship. The BPM manual (NRA, 1959) discusses grip, body

position (i.e., for a single hand-hold shooting position that no longer is advocated

for most noncompetition purposes), sighting and aiming, trigger squeeze, breath-

ing, follow-through, calling the shot,and rhythm.The current BPS manual (NRA,

1991) redefined the fundamentals to the following: “to shoot a pistol accurately, it

is first necessary to learn and understand the six fundamentals, or basicessential

components(emphasis added) of pistol shooting. These fundamentals are: position,

grip, breath control, sight alignment, trigger squeeze, and follow-through. These

fundamentals must be properly performed every time a pistol is fired” (p. 58). In

the competing entry-level 1998 BBP course, the fundamentals also are described

as essential but have only five steps, which are shooting position, shot prepara-

tion, sight alignment control, trigger control, and follow-through. In short, the so-

called “essential” fundamentals in these two competing courses are quite different

and conflicting in their explanations. In the Basic Personal Protection in the Home

course (NRA, 2000), the fundamentals are described asfollows: “like other forms

of handgun shooting, defensive shooting is based upon the fundamental principals of

pistol marksmanship, These fundamentals are aiming, breath control, hold control,

trigger control, and follow-through” (p. 37). These fundamentals, asdescribed in

detail in this manual, are inconsistent and in conflict with the essential fundamentals

asdescribed in the two previous courses. To further complicate matters, still another


major inconsistency exists between these civilian course fundamentals and those given in NRA law enforcement training.

Depicting Inappropriate Biomechanical Positioning

A fourth deficiency with current NRA courses, and one that may cause physical

harm, is advocating inappropriate biomechanical positioning, especially with a gun

that hasany significant recoil. For example, on pages 64 and 87 of the Personal Pro-

tection in the Home manual (NRA, 2000), there are inappropriate pictures for the

course material, which is self-defense. These photographs show the individual hold-

ing a firearm up with armsextended, bending backward at the lower back with the

shoulders behind the hips to counterbalance the weight of the firearm. Firearms with

significant recoil, such as those used for self-defense, push the shooters shoulders

further back and can cause microtears in the muscles of the lower back and other

potential back injuries. Also, recovery time for a second shot is much slower, and the

shooter can potentially be knocked off balance (which, as noted in Chapter 2, could

result in an inadvertent discharge). Consistent accuracy also is affected, asthe stu-

dent hasconsiderably more movement when firing multiple shots consecutively. Paul

Paradis has found that students who suffer from any kind of chronic back pain or

are elderly tend not to have any physical problems after completing a full-day course

of fire (6 hours’ shooting time; 100–150 rounds of high-powered ammunition) when

they lean forward at the waist, putting their shoulders in front of their hips. From the

authors’ experience, there needs to be more study on ergonomic issues in shooting

stances to ensure that instructors are not causing physical harm to their students.

Testing Learning Knowledge by Open-Book Exam

In NRA courses, basic beginner and instructor, the written test component that the

students must pass in order to receive a course completion certificate is open book.

The authors believe that it is not appropriate for a course designed to train people in

self-defense to use an open-book, rather than closed-book, type of exam. There is no

way for the instructors to make any real determination asto how much information

the student has actually retained. Unlike a target-shooting course, in which it may

be appropriate for a student to refer to a book, self-defense scenarios will not offer

that opportunity.

In addition, in our opinion, some questions on the NRA tests are poorly written,

and some are ambiguously worded. This is yet another area where human factors pro-

fessionals with expertise in test question construction and analysis could be of help.

Use of Impersonal Bull’s-Eye Targets

A sixth deficiency is that the NRA does not allow instructors to use humanoid tar-

gets, such as black silhouettes on a white background that are generally configured

and sized in the shape of a human being. Whether or not this is bowing to politi-

cal correctness, this does a disservice to students in that the real-life situation will

involve shooting at a human, normally with low light levels, should it become abso-

lutely necessary. In the interest of fidelity of training, the authors believe the training

Training 151

must be realistic, including the use of humanoid targets, which facilitates such things as teaching correct sight alignment technique. Of particular importance, there are moral and ethical considerations that a student must consider that are enhanced by use of a humanoid target, rather than an impersonal bull’s-eye or the current tombstone-style targets. The instructor must help the student confront the emotional issues in the classroom, rather than letting the student firstconfront these issues in

a crisis situation.

No Refresher Training Requirement

A seventh problem with the NRA program is that there is no requirement for peri-

odic refresher training for instructors or students. Given that most persons who own

handguns for personal protection rarely, if ever, fire their handguns—or even practice

safety procedures with their handgun without firing—proficiency in safety procedures

and practices drops off with time. This is well known to human factors professionals

for any kind of skills training. In light of this fact, persons should be encouraged to

take a refresher course that would allow for information update and refamiliarization

training in order to maintain the certificate. In the opinion of the authors, a short

refresher course should be taken at least every 2 years to maintain certification.

Course Standardization and Audits

Although their teaching materials provide some standardization of the NRA courses,

the programs, asactually taught, vary considerably. Many localities have their own

training programs that often conflict with other NRA programs currently in use.

Some national standards need to be developed. Audits at all levels of training are

needed to ensure current content is being taught, and taught properly. Lack of a sys-

tematic, sound audit system allows for both inconsistent content and instruction, and

enables incompetence to exist. Currently there is no audit system in either the law

enforcement or civilian firearm safety training programs.

COMMENTS AND SUGGESTIONS REGARDING SPECIFIC NRA COURSES

Content aside, the NRA full-course programs (nonorientation) have appropriate les-

son plans; these lessons are much like the military task, condition, and standards. The

basic outlines of these courses and comments and suggestions on them are as follows.

The Basics of Pistol Shooting (BPS)

This is a basic pistol-shooting course that orients the student toward target shooting

(NRA, 1991).

Lesson 1. Pistol Knowledge and Safe Gun Handling (2 hours with a 10-minute

break).

Lesson 2. Ammunition Knowledge and the Fundamentals of Pistol Shooting

(2 hours with a 10-minute break).

Lesson 3. Firing the First Shots (benchrest position; 2 hours with a 10-minute

break).


Lesson 4. Two-Handed and One-Handed Standing Shooting Positions (2 hours with a 10-minute break).

Lesson 5. Two-Handed and One-Handed Standing Shooting Positions (2 hours with a 10-minute break).

Lesson 6. Pistol Sports and Activities (2 hours with a 10-minute break).

If this course were solely applied to target shooting, formal and informal, it would meet the criteria generally needed. Lesson content could be strengthened as dis-cussed throughout this book by the authors. The NRA states that this is a basic course, and the word basic has different meanings to different people. One sugges-tion would be to determine what failures persist that lead to inadvertent and uninten-tional discharges and develop stronger safety programs to eliminate them.

The Basics of Personal Protection (BPP)

This now-discontinued course was the NRA’s first program for self-defense (NRA,

1998). If it was revamped to be the starting place for those buying firearms for self-

defense purposes, rather than target shooting, it could be altered to be a presentable

course. As it was, it did not meet the basics that were presented in the basic pistol

course described earlier. A comparison of the ammunition chapters illustrates this.

Another issue is the type of target used. Use of the more realistic humanoid-style

targets instead of the bulls-eye type would be appropriate for this class. This class

did emphasize the center mass sight alignment, appropriate to self-defense, rather

than the 6 o’clock hold (see Chapter 6) of general competition target shooting. The

course lessons and times are as follows.

Lesson 1. Handgun Knowledge and Safe Gun Handling (2 hours with a 10-

minute break).

Lesson 2. Ammunition Knowledge and the Fundamentals of Handgun Shoot-

ing (2 hours with a 10-minute break).

Lesson 3. Firing the First Shots (2 hours with a 10-minute break).

Lesson 4. Handgun Shooting Positions (2 hours with a 10-minute break).

Lesson 5. Firearms and the Law (2 hours with a 10-minute break).

Lesson 6. Avoiding Criminal Attack and Controlling a Violent Encounter (2

hours with a 10-minute break).

Personnel Protection in the Home (PPIH)

This is the self-defense course currently promoted by the NRA (NRA, 2000). The

course mandates that the basic pistol class (BPS) be taken as a prerequisite. How-

ever, in the instructor’s manual, the guidance given the instructor is far more open,

including military “DD214 with pistol qualification” as a substitute for the basic pis-

tol course. Unfortunately, no time frame is established as to how long before taking

the PPIH course the BPS course could have been taken to still meet the prerequisite

requirement. If the BPS and PPIH were given in conjunction with each other, the

authors believe the courses would be more effective. The NRA, in its PPIH guide to

Training 153

instructors, also recommends to “factor in extra time.” The PPIH lesson plan is as follows.

Lesson 1. Introduction to Defensive Shooting (50 minutes).Lesson 2. Basic Defensive Handgun Skills (3 hours, breaks as needed with

minimum of two 10-minute breaks).Lesson 3. Firearms and the Law: Possession Ownership, and the Use of Deadly

Force (1 hour or more).Lesson 4. Strategies for Home Safety and Responding to a Violent Confronta-

tion (1 hour with 10-minute break).Lesson 5. Selecting a Handgun for Self-Defense (30 minutes).Lesson 6. Sport Shooting Activities and Training Opportunities (20 minutes).

If you feel that this does not meet the criteria for carrying and using a concealed fire-

arm, the authors agree. As can be seen, the PPIH course meets three specific needs:

1. To train for basic ownership and use

2. To train for home self-defense

3. To train for concealed carry

Each is a different level, and some may be interested in the level that applies to their

personal use and concerns. Although the authors believe the general outlines are

appropriate, the content could be improved and the hours need to be lengthened.

Each course should have a refresher training multifaceted component as well.

Personal Protection Outside the Home (PPOH)

The outlines for the new Personal Protection Outside the Home course are not avail-

able, but the course content is directed toward applicable concealed carry and self-

defense use.

OTHER COMMENTS ON THE NRA PROGRAMS

As noted earlier, individual lesson content throughout the standard NRA courses

could be more thorough. For example, under the current climate, in the rush to get

concealed firearms permits, classes usually will be a mix of longtime shooters (who

often come in with a know-it-all attitude) and beginners who are somewhat unsure

of themselves. The class content should leave both groups feeling like they have

learned something of value. The standard NRA lessons leave much to be desired in

this regard, teaching only the most minimal content. For example, knowledgeable

instructors who know and understand the safety systems built into revolvers can

provide both groups with a better understanding of how the handgun works and why

modern quality revolvers are safe to use. This accomplishes three points that are

needed right from the beginning.


1. The student has more faith in a product (firearm, ammunition) that is going

to be both loud and, to a beginner, scary.

2. The instructor shows he is the expert from whom the student can really learn.

3. Both beginners and longtime shooters feel that they walk away with new,

important knowledge, and that their time and money were well spent.

Another content issue for instructors is that when a class starts out with mixed abili-

ties, the instructor needs to make it a challenge for the better shooters. Tightening up

on the groups (i.e., decreasing the dimensions of the target pattern fired by the expe-

rienced shooters) is one way; increasing the distance for the better shooters by plac-

ing their targets a few feet farther back is another. Each group comprises individuals

who want to feel that the overall course improved their abilities. As a side note, it has

been found by Paul Paradis and his fellow instructors that longtime shooters usually

move through the classroom material faster then new students who are struggling to

learn many new words and procedures. On the range, however, many of the longtime

shooters take more time in that they have to break old, bad habits and retrain them-

selves to new or different procedures.

CONCLUSION

Although we have focused on what we perceive to be the deficiencies of the domi-

nant and most pervasive self-defense firearm safety training programs in America,

the NRA programs, it should be noted that there is a great deal that is valuable in the

programs as they currently exist. However, incorporating well-known human factors

knowledge, principles, and methods into the NRA training program has the poten-

tial to significantly enhance their effectiveness. Such enhanced programs, if taken

by all persons possessing handguns, could, in our opinion, dramatically reduce the

number of inadvertent and unintentional shootings that occur annually in the United

States.

TRAINING WITH ADVANCED TECHNOLOGY

Much of this chapter has considered training in the traditional sense, including

classroom courses with written materials, dry-firing exercises, and actual firing on

ranges. However, new developments in the area of simulation and virtual reality may

become very important tools for effective training.

Consider that simulators can provide wide-screen, full-color projections of the

real world in which trainees are taught to react to various threats. Such simula-

tors have been used for decades, primarily for pilots of commercial and military

aircraft. Some of those simulators incorporate a dynamic base (motion) in which

aircraft maneuvers are felt by those piloting the simulator. Trainees in simulators

quickly become immersed in the simulated activities with the same kind of emo-

tional involvement as well as muscular control actions experienced in the actual

aircraft. In fact, heart rates and other physiological parameters that accompany sim-

ulated flight experiences approximate those in the actual aircraft environment. Such

flight simulators exist at aircraft manufacturers, aviation training centers, and the

Training 155

FAA and have been shown to accomplish high levels of proficiency even before the

pilots actually fly the particular aircraft for which they have received their training.

More recently, simulators are being used for a progressively increasing variety of

systems.

Anyone who has merely observed young people at an arcade dropping in coins to

drive simulated vehicles can recognize the high degree of involvement they experi-

ence. Much the same is true in driving simulators in which participants in driving

experiments are evaluated to determine how various (simulated) road conditions,

vehicle dynamics, or automobile systems (such as sighting aids or adaptive cruise

control, etc.) influence driver performance. Such simulators exist at automotive com-

panies as well as in research laboratories at various universities.

The use of sophisiticated simulators, especially employing virtual reality, is

currently too costly to consider for training the general population of gun users.

However, for application to training of law enforcement personnel, their use can

be expected to be very meaningful in that cost savings for ammunition, weapons,

and instructor time would be greatly reduced. It also is possible, perhaps probable,

that basic simulators can become economically feasible for general population gun

training.

An example of a highly programmable and interactive simulator is that used to

train police officers in the Los Angeles area (Dillow, 2006). Located in Huntington

Beach, California, it is capable of presenting trainees with a wide variety of realis-

tic shooting-potential scenarios. Trainees are armed with laser-equipped handguns,

pepper sprays and other devices, and officers need to decide how to act in crisis

situations. Though no simulator can faithfully represent reality, the fact that trainees

come out of it “with sweaty guns all the time” attests to how close to realism can

be achieved. As of the end of October 2006, over 2,000 officers had gone through

training in this simulator.

The authors are not aware of any statistical data to demonstrate the effectiveness

of these shooting simulators but do expect that positive results will become docu-

mented, based on what has been experienced with flight simulators.

FAILURE TO INVESTIGATE AND PUBLISH REPORTS

OF ACCIDENTS AND THEIR CAUSES

A common saying within the gun community is: “It is not if you have an accidental

discharge, but when you have one.” Inadvertent discharges are accepted as a fact in

firearms handling. Currently there are three potential sources for addressing the causes

of firearms injuries: military accident review, law enforcement internal investigations,

and criminal investigations. The military publishes accident investigations but often

the information is not disseminated as widely as it could be. Law enforcement sets the

standards in the community, but little is divulged as to the nature and causes of their

accidental/inadvertent discharges. In the investigation of these cases, the primary fear

of law enforcement departments is the potential for civil liability, most notably when

injuries occur. When injuries are not present, embarrassment appears to be the major

factor in not publishing/disseminating how the event could be prevented.


Regardless of the entity, little gets to the shooting public or public at large as to the causation factors. Historical records are often left to those who heard what hap-pened, frequently with no knowledge of the results of any scientific investigation,

if indeed there were any. Regardless of liability or embarrassment, each and every

shooting should be fully investigated scientifically, without political pressure, and

the results of that investigation published and maintained for historical review. This

information could be invaluable to improving handgun safety training.

REPORTING OF UNINTENTIONAL DISCHARGES

An important additional problem is that many accidents are not reported, mainly due

to fear of criminal prosecution. Often, important information could be developed if

the person having the discharge, be it mechanical or the result of some human fac-

tor, were to report it. That way, statistics and corrective actions could be developed

for society’s general safety. Perhaps a national system, such as exists in the aviation

industry for voluntarily reporting near misses without fear of legal reprisal, could be

implemented by Congress. The aviation system has worked extremely well.

NATIONAL PUBLIC DATABANK ON RECALLS AND POTENTIAL CATASTROPHIC TRAINING SITUATIONS

Currently, there are forensic organizations, such as the Association of Firearm and

Toolmark Examiner’s (AFTE), that have access to information about recalls, firearm

failures, and training mishaps. At the AFTE’s annual training seminars, this infor-

mation often is provided to members by a single member who has taken it upon him-

self to keep his fellow members safe. While his actions are commendable, there are

many others who would benefit by the increased dissemination of this information,

and the government should take on the responsibility of creating and maintaining

this databank as a public safety issue.

WHAT REFRESHER TRAINING SHOULD INCLUDE

Without continuing practice, the skills we learn can be lost. The safe and effective

use of a firearm is like learning a foreign language without the continuing opportu-

nity to use the training. Just as one’s command of a foreign language will decrease,

both handgun safety handling skills and accuracy will suffer. Numerous examples

exist of students reshooting qualification courses with loss of both the safety han-

dling skills and accuracy that were documented from earlier classes.

From author Paul Paradis’s experience, the following should be included in a

basic refresher course.

Basic firearm safety

Firearm specific armorers courses

Marksmanship

Basic fundamental training—both dry fire and live fire

Care, cleaning, and use

Carrying and transportation

Training 157

“What If” drillsActual live fire practice with an instructor

Avoiding confrontation

Introduction to different types of competition

Firearm misadventures

The opportunity for a wide variety of refresher training topics allows for developing

greater student interest and increased ability.

INSTRUCTOR ISSUES

Instructor Selection

A macroergonomic or systems deficiency of the NRA program is the lack of a sound

system of instructor selection, training, certification, and recertification. Unfortu-

nately, many persons are forced into teaching positions or are motivated by monetary

gain rather thanby genuine enthusiasm for the work. As a result, they go through a

routine with no enthusiasm or sense of professionalism. Many police departments

put their best shooters into training status, not realizing they may be poor instruc-

tors. Handgun safety training needs to be empowering, making the students feel

accomplishment. Enthusiastic instruction by competent instructors often can get

through to the most uninterested student.

Instructor Training

Instructors of any firearms handling course need to be conversant with the two major

elements involved—the person and the firearm. Our assessment is that most instruc-

tors currently are more familiar with the mechanical aspects and less so with the

human factors, especially as related to human deficiencies.

Instructor training for human limitations. It is commonly recognized that an

increasing number of workers (as well as retired people) who engage in repetitive

motion tasks involving their hands and arms are experiencing what is known vari-

ously as CTS (carpal tunnel syndrome), CTD (cumulative trauma disorder), RSI

(repetitive stress injury), or other similar terms that describe that a person has dimin-

ished capability in hand/arm muscular control due to repeated motions. In addition,

there are more people with physical disabilities, including those with loss of limbs

and even total blindness-seeking firearms instruction. And more numbers of elderly

persons are applying for concealed weapons permits for self-protection and thereby

having to take qualifying handgun courses. Instructors generally are not adequately

prepared for effectively working with them. Clearly, this is an area that needs to be

addressed in instructor training.

In-depth training on mechanics and correcting firearm failures. Currently,

the NRA expects its instructors to train virtually any person with any handgun.

Many instructors do not possess the mechanical skill to do any in-depth training

on mechanics or to correct minor firearm failures, including disassembly of com-

mon firearms for cleaning. Armorers courses taught by the manufacturers already

exist for many firearms. These courses should be expanded outside of the law


enforcement community and include instructors. Manufacturers would also benefit

from increased knowledge about their products in the community. Currently, the

NRA offers gunsmithing workshops to gunsmiths. These programs also need to be

expanded to instructors to increase their mechanical proficiency.

Students tend to believe in the instructor and their own abilities. When they can

understand from their instructor the mechanics and procedures, with solid reasons

why something works the way it does, it enhances their own self-confidence. This

includes ammunition and firearm mechanics, as well as the physical mechanics of

the body. Training in these areas, for instructors as well as students, currently is

superficial to nonexistent. An example is the NRA BPS course. Very limited infor-

mation is given about cartridge failures. When a cartridge is fired, the empty case

should not have bulges or cracks. If it does, this is indicative of something very

wrong with the ammunition or firearm. Firing should be stopped immediately, and

the firearm should be taken to a qualified gunsmith. Both the instructor and student

should be taught these warning signs.

Students also are intimidated by the noise and recoil of the firearm when fired. When

they understand the safety features designed into modern ammunition and firearms,

they tend to have fewer fears and learn more quickly. The problem is, if the instructor is

not taught those safety features, she or he cannot effectively teach the student.

No formal probationary period. All instructor training should be with a proba-

tionary period of working with a qualified instructor. Often, under-skilled persons get

certified and provide inadequate training. A related problem is the fact that the NRA

offers no help or guidance to instructor trainers, referred to as training counselors by

the NRA, in weeding out unqualified instructors. Regardless of the quality of the train-

ing program, improper presentation weakens the overall quality of the course.

What a Realistic Instructor Training Program Should Include

One could look at the suggested training for how individuals can keep their skills

current and just change his or her title to instructor. People can get an instructor

rating but administer little or no training, and they might not take continuing train-

ing to keep their skills current. Quality instructors will both train and retrain. The

list of potential training suggestions for former students, referred to earlier under

the “Refresher Training” title, is just as appropriate, if not more so, for instructors.

In addition to developing their technical skills, instructors need to continue devel-

opment of speaking and teaching skills. We believe recertification is necessary to

insure that current instructors are up to date and aware of new or expanded teaching

principles.

There is a great deal that can be said about the current NRA programs for instruc-

tors that is excellent. However, the authors believe the systematic application of a

professional Instructional System Development (ISD) process could significantly

improve the quality of NRA instructor training. This process is well established and

has been used successfully in developing and improving both military and indus-

trial training programs. As previously noted, there are human factors, industrial

and organizational psychology, and educational specialists who are professionally

trained and experienced in carrying out ISD.

Training 159

Implementing a True Professional Instructor System

More attention needs to be given to selecting, developing, certifying, and periodi-cally recertifying professional firearms instructors. The methods for doing this are

well known to the human factors and industrial and organizational psychology pro-

fessions, and could be implemented as part of the NRA training system. We are

confident that the result would be much-improved instruction and better-trained

students.

CREATING A NATIONAL ASSOCIATION OF PROFESSIONAL FIREARMS INSTRUCTORS

Unlike many other professions, except in law enforcement, there currently is no

national professional association of firearms instructors. Many instructors are not

aware of changes in equipment, procedures, and teaching methods—a need often

met effectively by professional societies for their membership. Developing a national

professional association for firearms instructors, such as exists in human factors and

ergonomics (i.e., the Human Factors and Ergonomics Society) as well as in many

other professions, could be helpful in raising the standards for both the firearms

instructor profession and the overall quality of handgun safety programs (e.g.,

continuing education and updating training seminars, sharing of knowledge, and

developing new training techniques). We note that there are several national and

international professional societies for law enforcement instructors:

American Society of Law Enforcement Trainers (ASLET)

National Tactical Officers Association (NTOA)

The National Law Enforcement Trainers Association (NLETA)

International Association of Law Enforcement Firearms Instructors, Inc.

(IALEFI)

Knowledge from these professional organizations could be helpful in establish-

ing a national association for all firearms instructors.

STRATEGIES FOR ENCOURAGING TRAINING

TESTING AND LICENSING

There are a number of factors that strongly argue for legally requiring all persons

who operate a handgun to become licensed by first passing a written and demonstra-

tion exam. Such an exam is needed to insure that handgun operators have a basic

understanding of handgun mechanics, fundamentals, and safety rules, and can com-

petently apply them. In most cases, of course, they would need to take a sound train-

ing program to gain that knowledge and skill. Because of the political quagmire of

mandated training for firearm ownership, it is questionable that any national testing

will be implemented. Some of the more important reasons for testing and licensing

are as follows.


Handguns are lethal. They fire projectiles, which, if they strike a human, can

seriously injure or kill them.

Untrained persons consistently violate basic handgun safety rules. At the

beginning of handgun training classes, students consistently commit a

variety of safety violations in handling a handgun. The more common of

these safety violations are described earlier in this chapter. If anything,

these beginning students are more conscientious than could be expected

of the untrained public in general—they were taking the course and were

consciously trying to handle their firearm safely. Because the evidence sug-

gests that virtually everyone who is untrained commits a number of serious

and potentially lethal safety violations in operating a handgun, mandatory

demonstration of handgun safety knowledge and skill acquisition seems

essential to protecting the public.

Many unintentional shootings are by untrained persons. In the authors’ col-

lective experience as expert consultants and witnesses in hundreds of shoot-

ing cases, almost all that were believed to be unintentional were committed

by a person who had not completed a recognized handgun safety course.

Thousands of persons are killed or injured each year in unintended and inad-

vertent shootings. A related human factors problem that currently must be

faced is how to get the general population to understand the need for train-

ing, as many accidents occur not only with the owner of a firearm but also

with some unintended handler. If every person were trained that the muzzle

was the dangerous end of a firearm and not to let anyone point one at them

for any reason, or to recognize the potential danger and immediately step

out of the way, the authors are convinced that many tragic deaths and inju-

ries would be averted.

PERSUASION/INCENTIVE APPROACHES FOR ENCOURAGING TRAINING

Were all persons required to demonstrate knowledge and competency in operating a

handgun before they legally could, it would serve as very strong incentive for them

to take a handgun safety course. The authors could imagine such programs becom-

ing as common and widespread as driver training courses. Further, as more per-

sons found that these courses improved their overall competency and accuracy with

handguns, that word would spread, serving to motivate even more persons to seek

training. Establishing well-publicized competitions for teams from various training

classes also could serve as an incentive.

In addition, monetary incentives could conceivably be used, such as government

funding for handgun training and shooting facilities for trained shooters. Training

class size and numbers increased dramatically with the advent of concealed permits in

Colorado. Award of a national concealed carry permit upon successful completion of a

truly adequate training program would likely be a strong incentive to take training for

many. Trained persons could be given privileges for access to other firearms currently

not allowed for sale or importation. A reward system appears to work. Undoubtedly,

given time, persons could come up with other creative forms of incentive.

161

10 Human Factors

and Forensics

HUMAN FACTORS ISSUES IN LITIGATION INVOLVING FIREARMS INCIDENTS

Much of this book has been devoted to the discussion of human factors that can result in an unintentional discharge of a handgun or inadvertently shooting someone. Accordingly, these same factors are ones that must be considered in both criminal and civil cases involving firearms to determine whether or not it is likely that the

shooting was inadvertent or unintentional. Human factors specialists are increas-

ingly being called to serve as expert witnesses in shooting cases to help a jury reach

conclusions about intention. A brief summary of these human factors considerations

follows. This is not intended to be a complete list, but rather a list of some of the

more common factors a professional human factors/ergonomics (HF/E) expert would

be expected to consider in shooting incident cases. In addition, unique aspects of the

case could require the human factors/ergonomics expert to rely on his or her profes-

sional experience and knowledge to identify other relevant HF/E factors as part of

the HF/E analysis process.

1. Situationally induced acute stress, which includes the stressors present in the sit-

uation as well as the common physiological, cognitive, and emotional responses

to acute stress as they match with the behavior of the involved parties.

2. Chronic stress level of the shooter and, as appropriate, other parties involved

in the incident. Consider evidence of both high lifestyle and high residual

stress. Also important are any cyclic stress factors that may be present at

the time of the incident.

3. Any physical environmental stress factors that appeared to be present at the

time of the incident, such as a very high noise level or impact noise, vibra-

tion, temperature extremes, poor illumination, or glare.

4. Whether or not fatigue might be a factor, including from lack of sleep, inter-

rupted sleep, or stress-induced fatigue, and resultant common physiologi-

cal, emotional, and cognitive affects.

5. Whether there was any event that took place that could cause the shooter

to have a startle response, which resulted in the firearm being inadver-

tently discharged.

6. Whether the shooter’s attention requirements were divided such that his

or her focus was on the threat source, rather than the firearm, given that

humans cannot reliably focus consciously on two or more things at once.


7. Had the shooter and or other parties been drinking, such that alcohol, with its known effects on human perception, reaction time, judgment, emotion-ality, and so forth could have been a factor in the shooting?

8. Had the shooter been taking medications, which could have affected his or her physiological, cognitive, and emotional processes and resultant behavior?

9. Were the shooter or other parties involved in the incident under the influence of methamphetamines, with their known cognitive and emotional effects, such as paranoia, emotional instability, and hostile aggressive behavior?

10. Was cost of compliance a factor, such as in the procedure for insuring that a bullet was not in the chamber?

11. Were there any design-induced human error factors present, such as perti-nent trigger forces required (i.e., too resistive or too sensitive), size misfit

(e.g., gun too large for the person’s hand), excessive or vague perceptual

demands and negative transfer of training (e.g., confusion from familiarity

with a firearm that the person had used previously, and which had some

different design features and/or operated somewhat differently)?

12. Were there any environmental conditions present that could have degraded

human performance, such as inadequate lighting; slip, trip, or fall hazards;

or excessive temperature, noise, or vibration conditions?

13. Did the shooter lack formal handgun safety training, have training of question-

able/inadequate content, or lack any training in recent years, and exhibit unsafe

behaviors typical of persons lacking adequate firearms safety training?

14. If the shooter has had formal training, did that training cover safety factors

relevant to the case?

15. Were there any interactions among the previously mentioned, or with

other factors, that could have resulted in the incident occurring inadver-

tently or unintentionally?

HUMAN FACTORS/ERGONOMICS PROFESSIONALS AS EXPERT WITNESSES AND CONSULTANTS IN LITIGATION

From the material covered in the prior chapters and summarized briefly earlier, it

should be evident that human factors/ergonomics (HF/E) has a critically important

role to play in the analysis of incidents involving the discharge of firearms to deter-

mine whether or not they likely were inadvertent or misdirected and, if so, what

appear to have been the underlying causes. From the authors’ experience, and that

of colleagues, the discipline of human factors and ergonomics is not well known or

understood by many judges, attorneys, and juries. On the other hand, many attorneys

are very aware of the solid basis for human factors testimony and, therefore, attempt

to exclude it in pleadings to the court (judge) when they recognize that the testimony

will hurt their position. To help those involved in litigation to better understand the

HF/E discipline, the Forensics Professional Group of the Human Factors and Ergo-

nomics Society has prepared a position paper regarding HF/E and the role of human

factors professionals as expert witnesses and consultants. It should be noted that both

Hendrick and Hornick were participants in the task force that prepared the position

paper. The following sections are quoted from that document.

Human Factors and Forensics 163

Arguments Supporting Human Factors and Ergonomics

Expert Testimony

1. Human factors and ergonomics is an established, internationally recognized sci-entific discipline and systems-design profession.

Overview:

The human factors and ergonomics discipline has roots stemming from engineering,

psychology, physiology, and pedagogy, and serves a unique system design function.

More than 60 years ago, military and industrial systems designers recognized that

traditional approaches of selecting and training operators and maintenance personnel

did not ensure acceptable or safe system performance. Consequently, a new body of

knowledge and skills began to form to determine human capabilities and limitations.

Later this evolving body of knowledge was extended to include equipment and system

design proposes. Knowledge about human capabilities and limitations, and skill in

applying it to system design, is the basis for the human factors and ergonomics profes-

sion. Human factors and ergonomics professionals serve to ensure that systems and

equipment are designed to be compatible with known human biomechanical, physi-

ological, psychological, information processing, and anthropometric characteristics.

In the design of consumer products, medical devices, complex aircraft and spacecraft,

transportation systems, manufacturing facilities and processes, office environments,

and a multitude of other applications, human factors and ergonomics professionals are

noted for contributing to increased human productivity, comfort, health, and safety.

Professional Societies:

Professional societies are serving the needs of human factors and ergonomics profes-

sionals in over 50 countries. Based on estimates from the International Ergonomics

Association, there are more than 25,000 people working as human factors and ergo-

nomics professionals around the world. The first professional society serving the ergo-

nomics discipline, The Ergonomics Society, was established in 1949 in Great Britain.

The principle professional society representing the needs of human factors and ergo-

nomics professionals in the United States is the Human Factors and Ergonomics Soci-

ety (HFES), established as the Human Factors Engineering Society of America in

1957. There are about 5000 members of HFES, representing 47 countries, participat-

ing in 21 technical and professional groups including Forensics, Safety, Consumer

Products, Computer Systems, Environmental Design, Industrial Ergonomics, and oth-

ers. Approximately 1500 members typically attend annual meetings of the HFES and

participate in scientific workshops, panel discussions, symposia, and technical paper

presentations that are published in the Proceedings of the Human Factors and Ergo-

nomics Society Annual Meeting. Other publications of the HFES include the highly

respected research journal, Human Factors, and a practice-oriented magazine, Ergo-

nomics in Design, both published quarterly. Approximately 15% of HFES members


report having been engaged in expert witness work at some time in their careers, most often in addition to other employment.

Design Guidelines and Standards:

Human factors and ergonomics professionals have authored many important system and equipment design guidelines and standards accepted and followed throughout the world. The U.S. Department of Defense Military Standard (MIL-STD-1472) on “Human Engineering Design Criteria for Military Systems, Equipment, and Facili-ties” has been a significant resource for military and nonmilitary system designers

for over 30 years. The ANSI/HFES-100 standard for designing hardware related to

computer workstations is recognized as the most comprehensive human factors and

ergonomics standard to follow when designing computer workstations. Human factors

professionals served an important role in evaluating the causes of the 1979 Three Mile

Island nuclear power plant incident and in authoring guidelines for designing future

process control centers to avoid human-machine interface problems that contributed

to that incident.

2. The scientific basis for the human factors and ergonomics discipline is well

established and continues to grow.

Academic Degree Programs:

Highly respected academic programs offering degrees in human factors and ergo-

nomics exist in many countries throughout the world. In the United States, there are

approximately 70 programs offering graduate degrees (either MS or PhD level) in

human factors and ergonomics. Research conducted in these programs continues to

add important new knowledge, tools, and skills upon which the human factors and

ergonomics profession is based. Research contributing to our understanding of human

response time, sensory and perceptual processes, information processing, and deci-

sion making are notable examples of contributions from academic institutions to the

scientific basis of the human factors and ergonomics discipline. The majority of human

factors and ergonomics practitioners working in the United States have received gradu-

ate degrees, either in a program devoted specifically to human factors and ergonomics

or in one of the primary disciplines such as engineering or psychology with specializa-

tion in human factors/ergonomics.

Government Sponsored Research:

U.S. Government agencies (e.g. Department of Defense, NASA, NIOSH, Department of

Energy, Department of Interior, Department of Transportation, etc.) have long records

of sponsoring research and contributing significantly to the growing body of human

factors and ergonomics knowledge. HFE professionals help to shape research priorities

as chairs or members of the many committees and projects of the National Research

Council, National Academy of Sciences, and the National Academy of Engineering.


Industrial Research:

A large portion of human factors and ergonomic practitioners are employed by com-mercial firms creating products or services that compete in the world’s marketplaces.

Human factors and ergonomics research and development, conducted by these com-

panies in support of their goals, are other valuable contributions to the scientific basis

for the discipline.

Scientific Journals and Textbooks:

Considerable information about the human capabilities and limitations applicable to

system and equipment design has appeared in peer-reviewed publications over the last

60 years. Examples of the types of knowledge available in this well-established and

growing database include: data about human physical characteristics (such as body

dimensions, weight, strength capabilities, and motor skills), sensory and perceptual

processes (such as vision, audition, reaction time, decision making, learning, and

information processing), response to physical environmental factors (such as noise,

vibration, temperature, acceleration, stress, and lighting), personal factors (such as

age, experience, and intelligence), and organizational factors (such as work incentives,

workload, and work system design, including safety and health systems).

Notable Publications Documenting the Human

Factors and Ergonomics Database Include:Human Factors and Ergonomics Methods edited by N. Stanton, A. Hedge, E. Salas, K.

Brookhuis, and H. W. Hendrick, 2004.

Forensic Aspects of Driver Perception and Response, 2nd edition, by P. L. Olson and E. I.

Farber, 2003.

Kodak’s Ergonomic Design for People at Work, 2nd edition, by Eastman Kodak Co., com-

bines Vol. 1 (1983) and Vol. 2 (1986), 2003.

Macroergonomics: Theory, Methods and Applications edited by H. W. Hendrick and B.

Kleiner, 2003.

Macroergonomics: An Introduction to Work System Design by H. W. Hendrick and B.

Kleiner, 2001.

Human Factors in Traffic Safety by R. E. Dewar and P. L. Olson, 2001.

Work Design, Industrial Ergonomics, 5th edition, edited by S. Konz and S. Johnson, 2000.

Warnings and Safety Instructions: Annotated and Indexed, 4th edition, by J. M. Miller, M.

R. Lehto, 2000.

Ergonomics Guidelines and Problem Solving edited by A. Mital, A. Kilbom, and S.

Kumar, 2000.

Warnings and Risk Communication edited by M. S. Wogalter, D. M. DeJoy, and K. R. Laugh-

ery, 1999.

Work-Related Musculoskeletal Disorders: A Review of the Evidence, National Research

Council, 1998.

Work Organization and Ergonomics edited by V. Martino and N. Corlett, 1998.

Human Factors Engineering for Forensic and Safety Specialists by W. Woodson, 1998.

Elements of Ergonomics Programs, DHHS (NIOSH) Publication 97–117, 1997.

Fitting the Task to the Human, 5th edition, by K. H. E. Kroemer and E. Grandjean, 1997.

Handbook of Human Factors edited by G. Salvendy, 1987; 1997.

Managing the Risks of Organizational Accidents by J. Reason, 1997.


Stress and Human Performance edited by J. Driskell and E. Salas, 1996.Evaluation of Human Work by J. R. Wilson and E. N. Corlett, 1995.Research Techniques in Human Engineering edited by J. Weimer, 1995.Work-Related Musculoskeletal Disorders (WMSDs): A Reference Book for Prevention edited

by I. Kuorinka and L. Forcier, 1995.A Guide to the Ergonomics of Manufacturing by M. Helander, 1995.Work Design by S. Konz, 1995.Human Factors in Engineering and Design, 7th edition, by M. S. Sanders, 1993.Work Practices Guides for Manual Lifting, NIOSH, 1981; 1993.Ergonomics Program Management Guidelines for Meatpacking Plants, OSHA, 1993.Human Factors Design Handbook, 2nd edition, by W. W. Woodson, B. Tillman, and P. Till-

man, 1992.Engineering Psychology and Human Performance by C. D. Wickens, 1990.Handbook of Human Vibration by M. J. Griffin, 1990.

Human Error by J. Reason, 1990.

Human Performance Engineering, 2nd edition, by R. Bailey, 1989.

Engineering Data Compendium: Human Perception and Performance edited by K. R. Boff

and J. E. Lincoln, 1988.

Dreams—Design and Destiny. Human Factors, 29(1), 111–121, by R. J. Hornick, 1987.

Human Engineering Guide to Equipment Design by H. P. Van Cott and R. G. Kinkade,

1972.

Manager’s Guide to Workplace Ergonomics, Business Legal Reports, Inc. (periodically

updated).

National Safety Council Accident Prevention Manual for Industrial Operations: Engineer-

ing and Technology (periodically updated with new editions).

National Safety Council Accident Prevention Manual for Industrial Operations: Adminis-

tration and Programs (periodically updated with new editions).

Some notable peer-reviewed scientific journals in which human factors and ergo-

nomics data are recorded include:Accident Analysis and Prevention

Applied Cognitive Psychology

Applied Ergonomics

Ergonomics

Human Factors

IEEE Transactions on Systems, Man and Cybernetics

IIE Transactions Information Display

International Journal of Ergonomics in Manufacturing

International Journal of Industrial Ergonomics

International Journal of Man-Machine Studies

International Journal of Occupational Safety and Ergonomics

Journal of Applied Psychology

Journal of Experimental Psychology

Journal of Sound and Vibration

Journal of the Acoustical Society of America

Journal of the Optical Society of America

Theoretical Issues in Ergonomics Science

Vision Research

In addition to the previously mentioned, many important papers are published in the

Proceedings of the Human Factors and Ergonomics Society Annual Meeting and in


journals published by professional ergonomics societies around the world, including those in Europe and the Pacific Basin.

3. Certification of human factors and ergonomics professionals and accreditation

of human factors and ergonomics academic degree programs are established.

Another measure of the professional status of a discipline is achieved when certi-

fication of practitioners and accreditation of academic degree programs have been

established. Two independent organizations based in the United States, the Board of

Certification in Professional Ergonomics (BCPE) and the Oxford Research Institute

(ORI), have been providing certification and professional development services to

human factors and ergonomics practitioners since 1992. Similar professional certifi-

cation boards exist in Europe for the European Union, as well as in Canada, Japan,

Australia, and New Zealand. The HFES has accredited 11 graduate degree programs

in the United States. Certification of practitioners and accreditation of academic

degree programs, although relatively recent developments, demonstrate the continu-

ing advancement of the human factors and ergonomics profession.

4. The utility and value of the human factors and ergonomics discipline have

long been recognized by government and corporate groups that support the

discipline’s growth.

There are many human factors and ergonomics practitioners employed throughout

academia, government, and industry. Some notable entities that have recognized the

utility and value of their human factors and ergonomics practitioners are:

U.S. GOVERNMENT

National Aeronautics and Space Administration (NASA)

National Transportation Safety Board (NTSB)

National Institute for Occupational Safety and Health (NIOSH)

Office of Science and Technology

U.S. Air Force

U.S. Army

U.S. Navy

U.S. Department of Interior

U.S. Department of Labor

U.S. Department of Transportation

U.S. Federal Aviation Administration

U.S. Coast Guard

STANDARDS ORGANIZATIONS

American National Standards Organization (ANSI)

American Society for Testing and Materials (ASTM)

International Standards Organization (ISO)

Society of Automotive Engineers (SAE)


INDUSTRY

Apple ComputerAT&T CorporationChrysler CorporationJohn Deere & CompanyEastman Kodak CompanyExxon Mobil CorporationFord Motor CompanyGeneral Motors CorporationHerman Miller CorporationHewlett PackardHughes Aircraft CompanyIBM CorporationIntel CorporationLiberty Mutual InsuranceLockheed MartinMcDonnell Douglas/BoeingMicrosoft CorporationOracle CorporationSteelcase Corporation3M CorporationsXerox Corporation

THE USE OF HUMAN FACTORS/ERGONOMICS EXPERTS

As with experts in other disciplines, opposing attorneys often challenge the use of a human factors/ergonomics expert. The Human Factors and Ergonomics Society Forensics Professional Group also addresses this issue in their position paper, as quoted below.

From time to time, testimony of human factors and ergonomics experts is challenged by opposing attorneys in personal injury, product liability, workplace injury, transpor-tation injury, or other civil and criminal cases. An attorney may oppose the introduc-tion of human factors and ergonomics testimony because:

1. The attorney has chosen not to use the services of a human factors or ergonomics expert for his own case presentation. That attorney then realizes, near trial, that the testimony of the opposition’s human factors or ergonomics expert likely will be effec-tive and thereby harmful to the attorney’s interests and positions.

2. The attorney believes that the human factors and ergonomics discipline provides information that jurors would know based on their own experience or “common sense,” and, therefore, challenges its utility in assisting judicial decisions.

3. The attorney, citing the “Daubert” decision giving judges more responsibility in admitting evidence based on their opinion of scientific credibility and acceptance, chal-

lenges the acceptance of the human factors and ergonomics discipline and its scientific


credibility. The U.S. Supreme Court case Daubert v. Merrell Dow Pharmaceuticals

Inc., 113 S. Ct. (1993) defined boundaries for acceptable expert testimony. The Supreme

Court decided that the trial judge, in federal cases, is responsible for ensuring the rel-

evance and reliability of expert testimony. The Supreme Court provided four factors

that can be considered by a federal judge when evaluating expert testimony:

• Can the theory offered by the expert be (and has it been) tested? Are the state-

ments made by the expert capable of empirical testing?

• Has the basis of the expert’s testimony been subjected to peer review or

publication?

• What is the reliability (i.e., the known or potential rate of error) of the scientific

evidence offered by the expert?

• Has the theory or subject matter of the expert’s testimony achieved “general

acceptance” in the scientific community?

4. The attorney considers that human factors and ergonomics testimony will “invade

the province” of the jury.

The arguments rebutting the previously mentioned challenges already have been

outlined at the beginning of this section (i.e., see “Arguments Supporting Human

Factors and Ergonomics Expert Testimony”). The paper concludes with the follow-

ing summary:

Summary

The purpose of this document is to present legitimate arguments that rebut typical

challenges to expert human factors and ergonomics testimony. Although detail could

be given for each of the arguments, it is clear even with this brief presentation that, in

fact:

1. Human factors and ergonomics is an established, internationally recognized sci-

entific discipline and system design profession.

2. The scientific basis for the human factors and ergonomics discipline is well

established and continues to grow.

3. Certification of human factors and ergonomics professionals and accreditation

of human factors and ergonomics academic degree programs are established.

4. The utility and value of the human factors and ergonomics discipline are recog-

nized by government and corporate groups that support the discipline’s growth.


5. The objectives of the civil and criminal justice systems are well served by a greater scientific basis for evaluating human behaviors and potential in court delibera-

tions and judgments.

This document was prepared by members of the Forensic Professional Group (FPG)

of the Human Factors and Ergonomics Society in 1996 and revised in July 2004. The

FPG is concerned with applying ergonomics and human factors knowledge, data, and

techniques to “standards of care” and accountability established within legislative,

regulatory, and judicial systems. The FPG serves to provide a scientific and technical

focus on issues being interpreted by legal theory and procedures. The FPG was estab-

lished in 1984 and has approximately 270 members in 2004.

AN APPARENT DOUBLE STANDARD

From the authors’ observations and experience, there appear to be two conflicting

standards of justice. When government employees (e.g., police officers) are involved,

the considerable resources of government come to the aid of their involved agent.

In these cases, the government often uses human factors testimony and embraces

human factors as a valid science. When a private citizen is accused of intentional

weapon firing, the usual prosecutorial theme seems to be punishment oriented, and

the scientific discipline of human factors tends to be denigrated by district attorneys

as junk science. Clearly, the same standard should be applied to both government

employees and private citizens. In not just cases of shootings by government employ-

ees, but also in cases involving shootings by private citizens, human factors should

be recognized unquestionably for what it actually is: a well-established, scientifically

based discipline—and one that can be highly useful to juries in determining whether

or not a shooting was intentional.

HUMAN FACTORS CODE OF FORENSIC PRACTICE

Because many of its members do get called upon and retained to serve as consul-

tants and expert witnesses in both civil and criminal cases, the Human Factors and

Ergonomics Society has established a Code of Forensic Practice, which appears

as Article V in its code of ethics. That practice code is as follows (Human Factors

Society, 2006, p. 397).

Article V—Forensic Practice

Human factors scientists and practitioners do not allow the adversarial system of juris-

prudence to affect the quality or integrity of their practice.

Principle 1

Members provide testimony objectively and without bias; their testimony is based on

credible data and/or scientific principles; they are prepared to identify the merits and

limitations of the data and principles as well as their own capability to interpret those

data and apply those principles.


Principle 2

Members avoid impugning the integrity of other expert witnesses without a factual, reasonable, and substantive basis.

Principle 3

Members do not accept fees on a basis contingent on the outcome of the matter.

Principle 4

Members accept that the client is the attorney who engaged them and not the client of that attorney who is party to the suit.

Principle 5

Except where required by the Federal Rules of Evidence, members avoid discussing the suit with others in a manner that would disclose the caption of the suit or parties involved, absent the permission of the engaging attorney, until the suit is absolved.

Principle 6

Members participating in a suit do not make public statements likely to influence or prejudice the judicial proceedings during their pendency.

Principle 7

Following suit resolution, members do not reveal information detrimental to the liti-gants’ or client’s interests, except where they believe silence would breach the greater duty of protecting public health and safety.

FINDING HUMAN FACTORS/ERGONOMICS EXPERTS

Listings of human factors experts may be found in the Human Factors and Ergonom-ics consultants directory, which can be accessed online at http://[email protected]. On the opening page, click on “Consultants Directory,” and, when it appears, you can click on “Expert Witnesses Only.”

Another HFES source is the annual Human Factors Directory and Yearbook. (Those who are members of the Forensics Professional Group have the letters FP following their address, phone number, and e-mail information.) To purchase the current directory and yearbook, contact HFES by Web site (http://[email protected]), phone: (310) 394-1811, or fax: (310) 394-2410.

Still another good source is the Board of Certification in Professional Ergonom-

ics (BCPE), which maintains an online listing of its certificants at http://bcpe.org

(phone 888.856.4685).


OTHER HUMAN FACTORS ISSUES TO CONSIDER IN FORENSICS

In addition to the numerous human factors issues covered in previous chapters, several other issues related to forensics in shooting cases are of note. They are as follows.

EFFECTS OF INERTIA ON TRIGGER PULL AND INTENT

The force required to pull the trigger often is presented in courts as a sign of intent to shoot, when, in actuality, it is a relative measurement that does not take into consider-ation other relevant factors (e.g., the physical forces acting on the gun, the location of the gun’s center of mass, the gun’s weight and geometry, the gun handler’s strength, and the familiarity of the handler with the firearm). In addition, there is the stress

caused by the situation and numerous other human factors that may have played a

role in the incident (see Chapter 2 for a description of many of these factors).

The laws of physics can play a significant role in some inadvertent discharges.

Inexperience or inattention when handling a firearm can cause the firearm handler

to apply force to the trigger, causing the gun to fire, without having consciously

pulled the trigger. The inertia of a mass in motion can require a great deal of force

to bring the object to a stop. In situations where a firearm is being moved rapidly,

such as drawing a firearm quickly or during aggressive encounters, the firearm has a

large amount of momentum. In a study performed by Royal Antles and Paul Paradis

(in preparation for publication), it was determined that the forces required to stop a

rapidly moving firearm can be more than enough to activate the firing mechanism.

Based on a study of the timing of certain shootings by Lewinski (2000), the forces

required to bring various handguns in motion to a halt were calculated. The results

for a Colt 1911 A1 are shown in Table 10.1. The mathematical formulas for these

results, as well the supporting model and the results for two other handguns, are

shown in Appendix B.

Table 10.1 gives various times for the two handguns to travel 5 feet and, for each

time period, the required force needed to bring the gun to a halt. As can be seen, the

force required to stop either of the handguns is more than enough to activate the fir-

ing mechanism. For example, moving a Colt 1911 five feet in 0.25 seconds requires

16.76 pounds of force to bring it to a stop—well above what it takes to depress the

gun’s trigger, even in double action. If the gun operator’s finger is on the trigger, and

his or her attention is directed elsewhere, he or she is likely to apply the required

force to halt the gun with the entire hand, including the trigger finger, thereby inad-

vertently firing the gun.

EFFECTS OF COUNTERBALANCING FIREARM WEIGHT ON TRIGGER PULL AND INTENT

The relationship between the center of mass of the firearm and the position of the

grip can affect the amount of force applied to the trigger while simply holding the

firearm. The center of mass is the balance point for an object. When an object is

held at the center of mass there is no tendency for it to tilt as a result of gravity. For

example, if two children are playing on a teeter-totter and have similar weights, they

can easily alternate who is high and who is low because the center of mass is near

the hinge in the middle. However, if a child and an adult with drastically different


weights are playing on a teeter-totter, the center of mass is closer to the adult and far-ther from the center. As a result, the child will not be able to lift the adult off of the ground. In the case of firearms, as the center of mass moves forward from the hand

(which is the pivot point), it will require progressively more force to be exerted by

the hand to hold the firearm level. When calculating the force required by the trigger

finger to hold a front-heavy firearm level, we find that the force is more than enough

to activate the firing mechanism. Table 10.2 shows a series of firearms and the force

required to hold them level.

The results show that in order to hold a pistol grip shotgun, which is an extreme

case for the distance between center of mass and grip, it can require 29.9 pounds

applied to the trigger to hold the 5.75-pound firearm level. The other two examples

are of firearms with a common design and are similar to many other firearms. In both

cases, the force to hold the firearm level exceeds the trigger pull. In all three cases,

TABLE 10.1

Forces required to stop a firearm Colt 1911 A1 39 oz. 5” barrel ammunition:

7 rounds Winchester 45 Auto 230 gr. full metal jacket (324 gr. total weight)

Time start to stop (s)

Maximum velocity (ft/s)

Maximum velocity (mi/hr)

Force required to stop firearm

(lb)


loaded (lb)

0.09 111.11 75.76 187.14 215.57

0.11 90.91 61.98 125.28 144.31

0.13 76.92 52.45 89.70 103.32

0.15 66.67 45.45 67.37 77.61

0.17 58.82 40.11 52.45 60.42

0.19 52.63 35.88 41.99 48.37

0.21 47.62 32.47 34.37 39.59

0.23 43.48 29.64 28.66 33.01

0.25 24.00 16.36 14.55 16.76

TABLE 10.2.

Trigger force required to hold a firearm level

Firearm type Force required from trigger finger (lbs.)

Firearm weight Average trigger pull (lbs)

Mossburg 500 12-

gauge with 5-shot

magazine unloaded

pistol grip shotgun

29.9 5.75 4.5–10

Colt Python 3” Barrel

.357 Magnum

unloaded

3.8 2.375 3

Ruger Blackhawk .357

Magnum unloaded

5 2.62 4.5


the firearms are weighed unloaded. Loaded firearms will weigh more, and, in each

of these cases, that loading will increase the force required to hold the firearm level.

Equations supporting this table are shown in Appendix B. Although the force to hold

the firearm level can be distributed among all the fingers, this shows that an inexpe-

rienced firearm handler who is unaccustomed to heavier-than-normal firearms can

inadvertently apply too much force to the trigger and activate the firing mechanism.

PEOPLE MAY ACT IRRATIONALLY FOLLOWING AN UNINTENTIONAL SHOOTING

Imagine if you had unintentionally just shot someone. First, you undoubtedly would

be stunned, in psychological shock. Second, you might fear being accused of murder

and going to jail for the rest of your life, or being sentenced to death. Third, you might

try to deny the reality of what just happened. You would be in an extremely stressful

situation. When persons are under severe stress, they may focus on the immediate

realities of what happened but lose perspective and make decisions appearing to be

irrational.

In one case investigated by two of the authors, an 18-year-old, whom we call Bill,

unintentionally shot another teenager who was reportedly his best friend. Bill testi-

fied that he was stunned and just sat in his bedroom in a daze for a couple of hours.

He said he eventually panicked and tried to cover up the incident. First, he took the

gun and threw it in a brook just a few blocks from his house (unrealistically think-

ing no one would find it or trace it to himself). Then, he wrapped the body in plastic

and dragged it upstairs and out the back door. Next, he called some friends to come

over and help him put the body in a boat stored in the backyard, which they did. (Bill

apparently thought (a) that his friends would never say anything to their parents or

the police, if questioned, and (b) that placing the body in the boat would keep the

police from finding it.) Bill tried to clean up the bloodstains by tearing out part of

the couch cover and stuffing, thinking that this action would actually be an effective

way of hiding the incident. Finally, when the police did show up, Bill initially lied to

them, saying that his friend had left earlier that day. When the police rather quickly

discovered the body in the boat and the obvious cover-up attempt in the room where

the shooting had occurred, Bill again lied, saying that his friend had shot himself,

when other evidence clearly indicated this was not the case.

In summary, Bill demonstrated the well-documented, classic symptoms of exces-

sive stress: initial shock and related freeze behavior, panic, narrowing of attention,

and related bad judgment and unrealistic decisions with respect to escape (i.e., hide

the body and remove evidence in the belief that it could actually work, and calling

friends, telling them of the accident, and asking them to come help—in itself, a

good indication that he probably did not shoot his friend deliberately). Had it been a

planned, premeditated murder, such unrealistic, seemingly foolish behavior would

be highly unlikely.

This example is cited to help human factors (and other) experts understand that

simple assumptions of intent and presumption of guilt must be avoided. It illustrates

what the authors have expressed earlier—that there are highly significant interac-

tions between a person inadvertently firing a gun and its design, and also that there


are severe consequences for not only the unintended victim and loved ones but for the unfortunate shooter as well.

OTHER EMOTIONAL REACTIONS TO SHOOTING SOMEONE IN SELF-DEFENSE

Elation. If someone has had to shoot an intruder or attacker in self-defense, that person is likely to have and express feelings of elation. These feelings may be mis-interpreted as indicating that the person was happy about having shot the other person—of cold-bloodedly rejoicing in the death of another. In fact, an immediate feeling of elation is to be expected as a reaction to having survived the threat to one’s life and, as applicable, the lives of others in the situation. As noted by the NRA (2000), it is an involuntary action resulting from the release of endorphins and other sensory and mood-enhancing chemicals into the blood stream. This feeling of ela-tion often is followed by feelings of guilt over having felt elation in the first place.

It is important for those involved in shooting cases to understand that elation over

surviving the threat is a natural, expected, and involuntary reaction.

Remorse. A normal feeling to having been forced to kill someone in self-defense

is sadness or remorse over taking the life of another. It is important that those

involved in litigating shooting cases recognize expressions of remorse for what they

are and not interpret the remorse as guilt over having shot someone unjustifiably.

Self-doubt. In some cases, the remorse may be accompanied by feelings of self-

doubt, wondering if there wasn’t some way they could have avoided killing the per-

son who threatened them. As noted by the NRA (2000), feelings of self-doubt also

are normal reactions to the aversion of having taken another person’s life, even when

legally and morally justifiable.

Acceptance. The final emotional stage, which persons hopefully reach, is accep-

tance of their action. This often follows the analysis of their action while having self-

doubt. The person comes to accept that the action he or she took was justified and

necessary, and that he or she simply was exercising the human instinct for survival.

OTHER FORENSICS SCIENCES RELEVANT TO HUMAN FACTORS CONSIDERATIONS IN SHOOTING CASES

A human factors or ergonomics specialist who is engaged to assist in determining

whether a shooting is inadvertent, unintentional, or intentional will be expected to

review materials coming from a variety of technical sources involved in shooting

investigations. The HF/E specialist might find the results of a forensics pathologist,

blood pattern reports, and other objective investigation information, such as trajec-

tory analysis, to be valuable in some matters, and perhaps less so in others. Close

interaction with the attorney or agency employing the HF/E specialist is highly

desirable (as it is in any forensic matter in which a human factors expert is retained)

to determine whether such information is likely to be informative.

177

11 Conclusion and

RecommendationsAs noted in Chapter 1, deaths and injuries from unintentional and inadvertent shoot-ings with handguns is a serious problem in the United States. Fortunately, it is one in which a true systems application of the scientifically based discipline of human

factors and ergonomics could greatly reduce the loss of human life, and the pain and

suffering of many others—not only the victims of those shootings, but also their

families and loved ones, and the shooters themselves.

A related problem is that, without the input of human factors and ergonomics

expertise, juries sometimes do not have the needed information to make an informed

decision regarding the nature of the shooting. As a result, persons can, and do, get

convicted of first- or second-degree murder when, in actuality, the shooting was

inadvertent (meaning they did not intend to pull the trigger) or unintentional (mean-

ing they intentionally shot the gun but had not intended to shoot someone).

The purpose of this book has been to describe the various human factors issues

that are involved in both of the previously mentioned problems, and to suggest the

various ways human factors and ergonomics expertise could be applied to mini-

mize them. A brief summary of the issues and how the application of human factors

knowledge could help follows.

HUMAN FACTORS CAUSES OF UNINTENTIONAL SHOOTINGS AND NEED FOR HUMAN FACTORS/ERGONOMICS EXPERTISE

In the first chapter, we identified the frequency and severity of unintentional and inad-

vertent shootings and also identified design and use issues that should be addressed

by human factors specialists as well as others interested in reducing accidents with

handguns.

In Chapter 2, we noted that there are well-documented causes of human error

that can come into play to cause a person with a handgun to inadvertently or unin-

tentionally shoot someone.

Stress. Perhaps the single most important of these is the nature of excessive

stress, such as that caused by being in a threatening situation. As described in Chap-

ter 2, knowledge about stress and the various ways and situations in which it can

result in an inadvertent or unintentional shooting is information that requires the

expertise of a human factors expert if a jury is to understand the situation clearly

and be able to render a proper verdict. Included was discussion of the various types

of stress, the physiological nature of stress, and the cognitive, perceptual, and emo-

tional responses to stress that can come into play in a shooting. Stress also interacts

with a number of other situational variables, such as startle, alcohol, drugs, and

more, in ways known to human factors professionals.


Fatigue. Yet another major factor can be fatigue. Here again, the human factors professional has scientific knowledge about the nature of fatigue and its behavioral

effects that can be factors in a shooting—knowledge that a jury may need to render

a proper verdict.

Other human performance factors. Other important human performance fac-

tors, well understood by human factors experts as they might relate to shootings, are:

startle, dual task performance, loss of balance, sympathetic contraction, involuntary

trigger pull, alcohol, over-the-counter drugs and methamphetamines, and cost of

compliance. Here again, these factors can be, and often are, involved in inadvertent

or unintentional shootings.

Human capabilities and limitations and their effects on human performance.

Also relevant is the human factors professional’s knowledge of basic human capa-

bilities and limitations, such as sensation, perception, reaction time, biomechanics,

cognitive and physical workload, anthropometrics, long- and short-term memory,

learning, and the performance effects of various physical environments, including

heat, cold, illumination, noise, and vibration. Juries need the professional knowledge

and expertise of human factors experts if they are to be in a position to render an

appropriate verdict.

In conclusion, we believe these kinds of knowledge about human performance,

and related human capabilities and limitations, often are highly relevant to the pro-

cess of determining whether or not a shooting was intentional, or inadvertent or

unintentional. We therefore recommend that whenever there possibly may be a ques-

tion of intent in a shooting case, professional human factors expertise should be

utilized in the investigation. If the human factors investigation determines that the

shooting may have been inadvertent or unintentional, that expert also should be a

vital witness for assisting the jury.

ERGONOMIC ISSUES IN HANDGUN DESIGN

A major ergonomic concern with the design of any consumer product is design-

induced human error. In Chapter 4, we went into considerable detail on the parts and

mechanics of the various kinds and makes of handguns, pointing out the ergonomic

characteristics that can cause inadvertent and unintentional shootings. Included were

such issues as a lack of standardization of safety controls, problems with trigger

forces and movement distances, and the lack of a positive indicator of bullets in the

chamber on many semiautomatics. Other ergonomic problems with specific hand-

guns are noted.

In addition, the mechanics of operation for different handguns are described,

including the safety problems some of these operational characteristics cause. These

take the form of confusion when transferring from one handgun to another, less-

familiar one, as well as operational features that can cause one to inadvertently dis-

charge the firearm.

Underlying these ergonomic safety deficiencies in handgun design and mechan-

ics are such human factors issues as negative transfer of training, cost of compliance,

biomechanics, and anthropometrics.

Conclusion and Recommendations 179

In light of the previously mentioned, we strongly recommend that the firearms

industry do what has been done for many other consumer products. Namely, that

any component related to safety be scientifically studied ergonomically to deter-

mine an optimal design, and then standardized across any given type of firearm

intended for use in home defense (e.g., semiautomatics, revolvers). When the same

general type of handgun is to be used by police officers and so forth, the standard-

ization should also apply to those firearms whenever practical (we recognize that

some features may have to be different, given the nature of police work as compared

with home defense). As has been done with numerous other consumer products, we

also strongly recommend that professional ergonomists be directly involved with

the firearms industry in doing the research and developing the standards. Further,

we encourage that the American National Standards Organization (ANSI) become

proactively involved and that handgun standards be developed as ANSI standards,

following the ANSI process. Although this will be of only limited use with existing

handguns, it would be extremely useful for new handguns and, in the long run, could

significantly reduce inadvertent shootings.

ERGONOMIC ISSUES IN AMMUNITION

DESIGN AND NOMENCLATURE

In Chapter 5, the designs of many types of ammunition were described, along with

the associated ergonomic deficiencies and resulting human factors safety issues,

which can lead to accidents and injuries. Of particular concern are the ergonomic

design problems with cartridge designations and other confusing features. These

include a lack of accurate and standardized designations of cartridge sizes and pow-

der charges, which leads to confusion regarding choice of the proper cartridge for a

given handgun. Included is the problem of interchangeability and noninterchange-

ability of cartridges. Other problems, such as incorrectly loaded cartridges and

unique problems associated with dummy cartridges, are also discussed.

Underlying the previously mentioned problems are the human factors issues

they cause. Of particular importance is the confusion resulting from the incomplete-

ness and lack of standardization of ammunition labeling, and the resulting problems

of discriminability.

In light of the previously mentioned, we strongly recommend that the firearms

and ammunition industries work with human factors and ergonomics professionals

to determine the type of labeling system that should be utilized for ammunition, and

then standardize that labeling system. As with our standardization recommendations

for handguns, we recommend that the scientifically determined labeling system be

incorporated as an ISO standard. We are confident that such a standardized labeling

system would greatly reduce the probability of persons choosing the wrong ammuni-

tion for a given handgun and, thereby, greatly reduce the accidents and injuries that

result from such errors.


SAFETY RULES

Another human factors issue noted is the confusion regarding the differences in the basic safety rules for handling a firearm that are advocated in different training

programs. We recommend that the NRA study these differences and, to the extent

practical, standardize a given set of rules for their training programs. We suggest

also that the NRA work closely with weapon manufacturers to identify not only cur-

rent safety issues but also those relative to emerging technologies for handguns. We

also recommend that they involve many human factors professionals in that process.

To insure that the training given is not detrimental to the trainees, trainers that are

not willing to work with the NRA and other agencies that have their own programs

also should utilize human factors experts.

PREVENTING UNAUTHORIZED ACCESS TO HANDGUNS

A critical human factors and ergonomics issue is preventing handguns from being

operated by unauthorized persons. For the immediate, we recommend that hand-

guns be kept stored, unloaded, in a secure lock box or with a locked trigger guard.

Whereas this is important for preventing any unauthorized access, it is particularly

critical in any situation where children otherwise can gain access to the firearm.

We also recommend that, as one or more of the various smart gun technologies

become fully developed, they be incorporated into any handgun designed for home

defense and, where practical, for law enforcement. We would note that at least one

state, New Jersey, already is building this requirement into law.

TRAINING

Improving the ergonomic design of handguns and standardizing those improvements

related to safety can, in the long run, reduce inadvertent and unintentional shootings.

For the present, however, we are faced with the fact that literally millions of hand-

guns are in use that contain the safety design deficiencies noted in this book. Further,

many of these handguns will continue to be in use for decades into the future. That

reality means that we must rely on a powerful human factors and ergonomics tool

known as training. And that implies adequate and effective training.

THE PROBLEM: NO TRAINING, INADEQUATE TRAINING, OR IMPROPER TRAINING

Unfortunately, as noted in Chapter 9, many of the persons who own and/or use

handguns have had no training on the safe use and handling of firearms. Further,

many who have received training received training of inadequate or questionable

content—often some years ago without any refresher training since.

A related serious problem is that what many persons have learned about han-

dling firearms has come from watching movies and TV, which very often depict

unsafe practices that directly violate fundamental safety rules. This inappropriate

training often begins with young children while watching characters handling guns

in cartoons, such as Elmer Fudd chasing a well-known rabbit. Often, in his hand-

gun training classes, Paul and his fellow instructors have had to work the hardest


with students who learned to use handguns (inappropriately and dangerously) from watching movies and TV. We believe the movie, TV, and cartoon industries need to take responsibility to make certain that they depict use of handguns in a manner consistent with the basic firearms safety rules. We are convinced that this can be

done without compromising the drama of the scene.

IMPROVING EXISTING HANDGUN TRAINING PROGRAMS

It has only been in the last decade that truly adequate home defense and concealed

carry safety training programs have been developed by the NRA. Even those courses

could be improved by subjecting them to a formal instructional system development

(ISD) process, utilizing human factors professionals. Accordingly, we recommend

that the NRA, and any other organizations providing handgun training, do just that.

PROVIDE INCENTIVES FOR PERSONS TO GET TRAINED

We are convinced that if all persons who use handguns were to take a truly adequate

handgun safety course, including periodic refresher training, the number of inadver-

tent and unintentional shootings would be greatly reduced. In fact, in the cases in

which we have been involved, most have been with persons with no handgun train-

ing of any kind.

In light of the previously mentioned, we recommend that the NRA and govern-

ment legislators at all levels seriously consider what they can do to provide incentives

for persons to get training. Several suggestions for such incentives are provided in

Chapter 9. Here again, human factors professionals could be of assistance.

We also believe completion of an adequate handgun safety training course (or

passage of a written and demonstration proficiency test) should be required in order

to obtain a concealed carry permit. Some state governments do have such a training

requirement, but most do not. Others have inadequate requirements.

INSTRUCTOR TRAINING AND PROFESSIONALISM ISSUES

In order to effectively deliver an effective handgun safety training course, well-

trained and motivated instructors who are skilled at delivering training are essential.

Related to this requirement is the establishment and maintenance of true profes-

sionalism among firearms instructors. Both of these issues have been addressed in

Chapter 9. A brief summary of both issues and our recommendations follow.

INSTRUCTOR SELECTION ISSUES

A macroergonomic or systems deficiency of the NRA program is the lack of a sound

system of instructor selection, training, certification, and recertification. From Paul

Paradis’s extensive experience, many persons become firearms instructors simply

for monetary gain, rather than because of genuine enthusiasm for the work. Police

departments sometimes put their best shooters into training status, not realizing they

may be poor instructors. We believe that criteria and methods should be developed

for selecting firearms instructors, much as is done for many other positions, such as


in industry, government, and the military. Many human factors professionals have formal training in personnel selection and development, including the underlying job analysis and selection test development (or selection) and validation procedures. Therefore, they are in a position to assist the NRA or others in developing a valid selection program for firearms instructors.

INSTRUCTOR TRAINING ISSUES

Program standardization and accreditation. Perhaps the most serious instructor

training issue is a lack of standardization. There currently is no standardization

nationally, and regional, state, competitive, military, and law enforcement programs

around the country vary widely in their scope and content. Many human factors

professionals, as well as industrial and organizational psychologists and educational

specialists, have the knowledge and skills in ISD to address this issue and the related

one of program accreditation. This is done for programs in many other disciplines,

including human factors and ergonomics, and clearly could be done for firearms

instructors. We would like to see the NRA take the lead in establishing an indepen-

dent organization for developing an accreditation system for firearms instructor pro-

grams, using human factors and other experts, following a systematic ISD process.

Should a national professional society of firearms instructors come into being (see

following), that organization would be a logical agency for developing and adminis-

tering an accreditation program.

Working with people with physical disabilities. Anincreasingly important prob-

lem is that instructors are not taught how to work with people with physical disabili-

ties, yet they are expected to develop solutions for these students. Given the aging of

the U.S. population, we can expect the number of persons with physical disabilities

associated with aging to increase. It is our recommendation that this area be added

to instructor training courses.

Lack of in-depth training on mechanics and correcting firearm failures. As noted

in Chapter 9, NRA instructors are expected to train virtually any person with any

handgun. Many instructors do not possess the mechanical skill to do any in-depth

training on mechanics or to correct minor firearm failures, including disassembly

of common firearms for cleaning. Armorers’ courses taught by the manufacturers

already exist for many firearms. We recommend that these courses be expanded out-

side of the law enforcement community and include civilian firearms instructors.

Instructor certification. As in other professions, we would like to see a cer-

tification program established for firearms instructors. Author Hal Hendrick was

instrumental in developing a certification program for human factors and ergonom-

ics professionals. He believes that professional certification has increased the level

of competency and professionalism within his discipline, as well as in others. An

integral part of certification is not only meeting a basic set of education and training

standards, and passing a comprehensive competency test, but also periodically tak-

ing professional updating courses to maintain certification.


CREATING A NATIONAL ASSOCIATION OF PROFESSIONAL FIREARMS INSTRUCTORS

Unlike many other professions, except in law enforcement, there currently is no national professional association of firearms instructors. From Paul’s experience,

many instructors are not aware of changes in equipment, procedures, and teaching

methods—a need often met effectively by professional societies for their member-

ship. Developing a national professional association for firearms instructors, such as

exists in human factors and ergonomics (i.e., the Human Factors and Ergonomics

Society) as well as in many other professions, could be helpful in raising the stan-

dards for both the firearmsinstructor profession and the overall quality of handgun

safety programs (e.g., continuing education and updating training seminars, sharing

of knowledge, and developing new training techniques). Such a professional society

also could take responsibility for developing an accreditation program for firearms

training programs. We recommend that either the NRA or an independent group

of senior firearms instructors take the initiative and form a national professional

organization for firearms instructors. The existing professional organizations for law

enforcement instructors potentially could be of assistance in this endeavor.

FINDING HUMAN FACTORS/ERGONOMICS SPECIALISTS AND EXPERTS

There are two domains in which you might wish to contact human factors and ergo-

nomics professionals. First, for general applications, such as equipment, software, or

work design, procedures, training, and so forth, there are the three primary sources

noted in Chapter 10: Human Factors and Ergonomics Society Directory and Year-

book, the HFES Consultants Directory, and the Board of Certification in Profes-

sional Ergonomics (BCPE) online listing of its certificants. Internet Web Sites also

have general human factors and/or ergonomics links, which identify organizations

and/or individuals claiming such expertise.

For human factors and ergonomics professionals who engage in forensic mat-

ters and who testify as human factors expert witnesses, in addition to the sources

mentioned earlier, a search of the Internet will quickly identify individuals claim-

ing human factors expertise as well as consulting organizations for that purpose. A

representative search might start with Legal Expert Pages, Jurispro, and others. All

seem to have links to other sites that have human factors and/or or ergonomics areas.

It should be noted that for forensic/litigation resources, the term human factors still

is more commonly used than ergonomics.

185

Appendix A

Case Studies of

Inadvertent and

Unintentional ShootingsThis appendix contains a brief summary of 12 inadvertent or unintentional shooting cases that have been investigated or studied by one or more of the authors. Following a brief description of the case, the major probable causal factors are given. All of the causal factors noted are described and explained elsewhere in this book. For each case, the applicable chapter is noted for each factor given in the analysis.

In addition to the cases in this appendix, for the purpose of illustrating specific points

in the text, additional cases are presented in several of the book chapters themselves.

CASE 1. A FATHER INADVERTENTLY SHOOTS HIS DAUGHTER

One late afternoon, a father comes home and hears someone up in his bedroom. He

grabs his handgun and goes up to investigate. He approaches the bedroom closet

and opens the door. Suddenly, a figure jumps out at him yelling “surprise.” A shot is

fired and his daughter, who was trying to surprise her father by hiding in the closet,

was killed.

Analysis. The stress imposed on the father by fearing an intruder in his bed-

room, coupled with the startle caused by his daughter jumping out and yelling “sur-

prise,” resulted in an involuntary muscle reaction in the father’s hands and fingers,

thus causing him to pull the trigger (see “Startle” and “Involuntary Trigger Pull” in

Chapter 2). The father violated the basic firearms safety principle of “Always keep

you finger off of the trigger until ready to shoot” (see Chapter 7). Basic tactical

training in a civilian environment would have been appropriate as well: No one was

in physical danger; had the father simply left the house and called the police, his

daughter would have been embarrassed but likely still alive.

CASE 2. ONE TEENAGE BOY INADVERTENTLY SHOOTS ANOTHER

Two teenage boys were examining one of the boy’s father’s firearms, a semiauto-

matic handgun. Both boys had questionable firearms training from their parents. The

boys noticed that the firearm was loaded and attempted to unload it. The gun had a

slide that was difficult to pull to the rear, so one boy got in front of the other to try


to help grasp the slide. The firearm discharged and the boy in front was killed; the

other was sentenced to 10 years in prison.

Analysis. The father failed to follow the basic safety rule of “Store guns so they

are not accessible by unauthorized persons” (see Chapter 7; also “The Problem” and

“External Restraints” in Chapter 8). The boys lacked adequate handgun training (see

Chapter 9) and failed to follow the basic safety rule of “Always keep the gun pointed

in a safe direction” (see Chapter 7) (in this case, while multitasking, which makes

compliance far more difficult and takes greater conscious attention than when single

tasking; the boys failed to recognize the potential danger and exercised improper

behavior while engrossed in the problem at hand [see “Divided Attention” in Chapter

2]). Minimal training in just firing firearms is not enough.

CASE 3. MAN INADVERTENTLY SHOOTS HIS GIRLFRIEND

A man bought his girlfriend a semiautomatic firearm. While trying to unload it, she

jammed the cartridge in the gun. She gave the gun back to her boyfriend and positioned

herself in front of him while he tried to un-jam the handgun so that she could see how

to do it. The gun fired, mortally wounding her. Neither had any formal training.

Analysis. Lack of handgun training and related failure to recognize the potential

danger on the part of both the man and his girlfriend (see Chapter 9). Failure to be

aware and follow the basic safety rules of “Always keep the gun pointed in a safe

direction” and “Always keep you finger off of the trigger until ready to shoot” (see

Chapter 7); in this case, while multitasking (which makes compliance far more dif-

ficult and takes greater conscious attention than when single tasking [see “Divided

Attention” in Chapter 2]), resulting in inappropriate behavior from being engrossed

in the problem at hand.

CASE 4. POLICE FIRE 31 SHOTS AT YOUNG MAN AT CLOSE RANGE, 30 AND 1/2 MISS

Two young men were intoxicated and handling their firearms carelessly. One of the

young men’s revolvers discharged, hitting his friend in the hand. In shock, he fled on

foot and for whatever reason reloaded his revolver. Police investigating were told that

he went down an alley. The alley was poorly lit as they traveled single file looking for

the shooter. As one officer passed the young man who was hiding in a garbage alcove,

the shooter, realizing it was a police officer, threw his firearm out. At that time one

of the officers yelled “gun” and both started firing toward the direction from which

the gun came. Thirty-one shots were fired; both officers claimed the other officer or

the suspect fired first, and neither officer claimed to have yelled “gun” but both said

they heard it. The suspect’s revolver was recovered from the middle of the alley with

a fully loaded cylinder; it had not been shot. One shot hit the suspect in the femur

after ricocheting off a concrete block pad (trace evidence brick material was found to

be in the bullet recovered from the femur). Thirty bullets missed. Dead at the scene:

two garbage cans (DVD A, Case 4.1).

Analysis. One likely cause of these shooting misses is a phenomenon known as

sympathetic discharge. When two shooters are concentrating on aiming at the same

Appendix A: Case Studies of Inadvertent and Unintentional Shootings 187

target, one fires, and the shock/interruption/tensing of the other would cause him to

shoot also, which can lead to both shooters shooting very inaccurately—particularly

when exacerbated by a high-stress situation, such as this one. This is a phenomenon

that Paul Paradis has observed a number of times on shooting ranges. The poor

illumination condition also may have been a factor. Clearly, from the diagram, one

officer was not even shooting in the direction of the suspect—the back left side of the

alcove as you face it from the alley. The other officer was shooting at the unarmed

suspect who posed no danger to either officer, as he was no longer armed.

CASE 5. SECURITY GUARD INADVERTENTLY SHOOTS

HIMSELF WHILE PRACTICING DRAWING HIS REVOLVER

A security guard, who was bored one night, unloaded his revolver and was practic-

ing drawing it from a holster. He was interrupted by a phone call and loaded his gun

while on the phone. A short time later he started practicing his drawing again and

shot himself in the foot. The revolver was a Smith & Wesson .38 Special, and the

case rims were visible from the rear but not noticed by the guard.

Analysis. Failure to mentally complete a safe training task before returning the

revolver to a loaded condition. Interference of intervening activities with subsequent

lack of recall of having loaded his gun (see “Recall Interference” in Chapter 2).

Failure to follow three basic safety rules: “Always keep the gun pointed in a safe

direction,” check to insure that the gun is not loaded (prior to resuming the practice

of drawing his gun), and “Always keep your finger off of the trigger until ready to

shoot” (see Chapter 7). Familiarity appears to have led to inappropriate behavior.

CASE 6. FIREARMS INSTRUCTOR INADVERTENTLY

SHOOTS LIVE AMMUNITION

DURING DRY-FIRE PRACTICE

A firearms instructor purchased a new .45-caliber revolver that used moon clips. He

started practicing with dummy rounds and noticed that the cartridges sometimes

hung up during the loading process. He retrieved some live rounds and tested the

firearm with them. To his relief the firearm functioned correctly. He laid the firearm

down, made dinner, and watched TV after dinner. While engrossed in the TV he

picked up the firearm and started practicing his dry-fire drills, firing the gun. Dam-

aged were his house wall, pickup truck, and pride.

Analysis. Failure to fully complete an intervening live fire-testing task during

dry-fire practice by returning the gun to a safe dry-fire condition. This failure was

coupled with memory recall interference by additional intervening tasks, causing

him to not remember reloading the handgun (see “Recall Interference” in Chapter

2). Upon completion of the live fire testing, failure to follow the basic safety rule of

“Always keep the gun unloaded until ready to use” (see Chapter 7). Failure to give

primary attention to the handgun, including noting that it was loaded, while involved

in multitasking (i.e., also attending to his TV program; see “Divided Attention” in

Chapter 2).


CASE 7. WOMAN INADVERTENTLY DISCHARGES

HER HUSBAND’S SEMIAUTOMATIC

A woman went with her husband to the range after not getting much sleep the night before. Her husband asked her to retrieve his backup gun, a Walther PPKS .380. She retrieved the gun, pulled back the slide ejecting the round in the chamber, removed the magazine, and then pulled the trigger to decock the gun. The gun fired the round

that was left in the chamber through the windshield of his car; fortunately the gun

was always kept pointed in a safe direction and no one was hurt. The Walther had

a loaded chamber indicator and a decocker, and she had experience with firing the

gun in the past.

Analysis. Sleep deprivation resulted in her failure to adequately attend to a criti-

cal safety cue (i.e., the loaded chamber indicator) and to follow proper safety proce-

dures for decocking the gun (see “Fatigue” in Chapter 2).

CASE 8. AMATEUR GUNSMITH UNINTENTIONALLY

SHOOTS HIMSELF IN THE HAND—TWICE

A would-be amateur gunsmith and new gun range owner, who was a self-taught

shooter, modified the action on his 1911 A1 Colt to lighten the pull on the trigger.

When he went to shoot it as fast as he could, his support hand separated from his

shooting hand and he shot himself in the support hand. When demonstrating to a

friend later what had happened, he shot himself again.

Analysis. The gunsmith exhibited a lack of adequate training coupled with a

know-it-all attitude (see Chapter 9). As a result, he violated the basic safety rule of

“Know how to use the gun safely” (see Chapter 7).

CASE 9. UNINTENTIONAL SHOOTING (SHOOT TO SCARE/WARN)

A young man was being harassed and threatened by three opposing gang members

in the evening. He pulled a poor-quality, inexpensive, fixed-sight handgun out and

yelled at them to go away. There is no doubt that they saw his handgun but continued

to threaten and come closer. He fired a shot and one of them fell down dead. When

the police came, he claimed that he tried to shoot between them to scare them off.

Later testing determined that the sights on the gun were not sighted in correctly (i.e.,

the gun does not hit where one aims). The young man had no known experience with

guns and no known past training.

Analysis. As already noted, the sights were not accurate, which would cause the

bullet to go in other than the intended direction, thus possibly hitting the victim,

even if the shooter sighted properly—which, for the reasons that follow, is unlikely.

Secondly, there was low illumination, thus making it difficult to both see the gun

sights and to clearly see the three threatening gang members. Thirdly, the high stress

resulting from the threat also could have exacerbated the inability of the shooter

to aim accurately (see “Stress” in Chapter 2). Finally, the lack of training in the

fundamentals of firing a handgun could have resulted in the shooter firing inaccu-

rately and, thus, unintentionally shooting the victim (see Chapter 6). There also is


the possibility that the gun was a poor fit for the shooter’s hand (see “Proper Fit of

Hand and Firearm” in Chapter 6).

CASE 10. FIGHTING OVER A HANDGUN: INTENTIONAL OR INADVERTENT?

The following case scenario is one that repeats itself over and over again—two or

more people struggling over the control of a firearm.

Alice and John were ending their romantic relationship; Alice found that John

had been dating other women while living with her. Alice confronted John with what

she knew, and also called the other women. John, who had been accustomed to living

off of Alice, retrieved his handgun and threatened to commit suicide. Alice grabbed

at the gun, trying to take it away from John. The gun went off, shooting John at a

close range (DVD Appendix A, Case 10.1 and 10.2).

Analysis. It often is not possible when two or more different hands are fighting

over a gun to be able to tell how the gun was discharged and what the intent was.

Obviously, one person was holding the gun and, most likely, was the one whose

finger was on the trigger. However, sometimes the other person, in reaching for the

gun, may initiate the discharge. It is relatively easy for a person not holding the gun,

but grabbing at it, to either hit the gun handler’s trigger finger, or the trigger itself,

during a struggle over a gun. Testing conducted by two of the authors (Hendrick and

Paradis) demonstrated that a 7-year-old child can force the trigger finger down on a

large male adult. This can occur because human fingers can apply a lot of force when

gripping something but have far less ability to resist being pushed down.

As an added note, in numerous cases, gun shot residue (GSR) has been found on

the hands of the person who stated that he or she was trying to take the gun away

from the other person. Often, the victim’s hands have no residue, most likely due to

being covered by the other person’s hands in the struggle over the gun.

CASE 11. MILITARY RANGE TRAINING: PERSON MISTAKEN FOR A TARGET

One of the authors (Paradis) was contacted by the commanding general’s office of

a large military base. A shooting had happened in which a soldier had been badly

injured on a military range. The commanding general wanted an unbiased technical

investigation to determine what had happened, how it happened, and how to ensure

that it did not happen again. As one might have guessed, there were multiple per-

spectives on what had happened, and how it had happened. In order to understand

the situation, go to DVD Appendix A, Case 11.1.

The range was positioned so that soldiers had to assault a bunker from a firing

line to a target traveling from northeast to southwest. Smaller bunker/firing positions

acted as both danger areas and potential cover as the soldiers moved forward toward

the target objective. Typically, two personnel assaulted the target bunker at the same

time with remaining members of the unit behind the firing line preparing for their

turn, or resting after completing their run through the course. Redlanternswere

requiredtobeplacedonbothsidesoftherangeassafetylightsbythepersonnel


running therange,but were not present. These maneuvers were required to be done at night.

On the southeast side of the range area was a gully that traveled norththeast to southwest, with a finger of the gully coming out east alongside the target bunker. The

actual target silhouette was humanoid shape and had a thickness of approximately

one-quarter inch. Viewed from the firing line in the daytime, it was easy to make out

the silhouette shape of the target. As can be seen on the referenced DVD, at night

with the hilly landscape the silhouette became difficult to see.

During one of the last maneuvers of the night, after midnight, a sergeant who

was helping to conduct the range was shot. The entry of the bullet was from the

forward left shoulder and out through the back. The bullet’s path was front to back,

left to right and upward. After the shooting took place the range was closed down

and interviews were conducted with all personnel present. The officer in charge of

the range felt that the bullet that hit the sergeant was a ricochet from the small rocks

scattered throughout the range. The soldier who had fired the shot, it was found later,

was using a laser sight on his rifle and had an NCO with him who had demanded that

the soldier fire, as he believed the dot from the soldier’s laser was on the correct tar-

get. The NCO only saw one dot on the target and believed that was his soldier’s laser

dot. The soldier had first refused, as he was not sure of his target, but eventually did

fire as ordered by his superior. This NCO was adamant that the soldier’s weapon had

been pointed in the correct direction and that the projectile must have ricocheted off

a rock. It also was found that another officer running the range had told the soldiers

to use the gully on the left side of the range for both cover (protection from being

struck from an incoming projectiles) and concealment (protection from being seen

by an aggressor). Thisgullywasactuallyoutsideofthelimitsoftherange.

The ammunition that was used in this case was a frangible type bullet. Test

fires into small rock using panels of sheetrock as a witness board showed the bullet

functioned as designed, and broke apart upon impact with anything hard—even with

glancing blows. During the examination of the soldier’s parka, a perfectly round

entrance hole was found with bullet wipe around the hole. (“Bullet wipe is the dis-

colored area on the immediate periphery of a bullet hole, caused by the transference

of residues from the bearing surface of the bullet. These dark gray to black residues

typically contain carbon, lead, bullet metal, and possibly other constituents such as

bullet lubricant and primer residues. Bullet wipe occurs at any range of fire so long

as the bullet has not passed through any intermediate object” [Haag, 2006, p. 304]).

Thepresenceofthiswipeaswellasthetestfiresoftheammunitionusedinthis

incidentshowedconclusivelythataricochetdidnottakeplace.

A reenactment was set up at night and it was found that the target silhouette was

almost invisible viewed from the side (i.e., from the position of the shooter). Also,

the NCO who was shot had an appearance very similar to the target silhouette. Dur-

ing the initial search of the area many shell casings were found inside the gully. The

intermediary bunkers of the range also showed that this was not the first time that

projectiles had come from downrange toward the firing line, only the first time that

someone had been injured.

Analysis. As may be noted, there were several contributing factors to this unin-

tentional shooting. Had any one of these factors not been present, this fatal incident


probably would not have occurred. First, as a result of the failure to have the safety lanterns present, there was inadequate lighting to be able to determine the limits of the range and which direction was downrange. Secondly, instead of following the intended path, the solders used a gully that was actually outside of the range, ulti-mately placing them in the wrong position relative to the target (and the victim), thus causing the target to be viewed edge-on, making it virtually impossible to see. As a result, the only silhouette visible was the victim’s, which understandably could thus be assumed to be the target (see “Priming” in Chapter 2). Based on the casings found in the gully, using it had been a reoccurring practice. Thirdly, the NCO supervising the shooter violated good safety practice by ordering the shooter to fire when the

shooter indicated he was unsure he was aiming at the intended target. Fourth, the

NCO who was shot had the appearance (silhouette) of the target (this can be seen in

the referenced DVD figure). Had he had any type of safety light on, he would clearly

have been identified as a range person and not a target.

The author, Paradis, received a commendation from the base commander of

the base.

CASE 12. ANALYSIS OF A HANDGUN IN A

SUSPECTED INADVERTENT SHOOTING

A defense attorney asked a criminalist to inspect a double-action Beretta model

85 Cheetah FS .380-caliber semiautomatic, which was involved in a shooting. The

attorney believed the defendant shot the gun inadvertently but was looking for physi-

cal evidence to support his case.

Part of the analysis centered on the manual for this handgun that was sent from Beretta

to the criminalist. It was dated 10/90 and, on page 13, had the following warning.

WARNING: Always ensure that the safety is fully engaged until ready to fire. A safety

is fully engaged only when the safety can move no further into the safe position. A

safety which is not fully engaged will not prevent weapon discharge.

It was noted that a later edition of the manual for this firearm, dated 9/99, did not

have this warning. It is unknown why the warning was excluded in later editions, as

the gun would fire with the safety halfway on (partially covering the red dot [fire]

indicator on the slide). During testing, it was noted that the safety lever stopped and

felt fully engaged, but was not, and the gun was capable of firing. When the safety was

fully engaged the hammer would go down to the frame without firing (manual safety-

decocking lever). When decocked, the hammer served as a visual indicator that the

safety was fully engaged. This feature was not discussed in either of the manuals.

Both the 1990 and 1999 manuals were for multiple models: 81BB, 82BB, 82F

84BB, 84F, 85BB, 85F, 87BB, and 87BB/L.B for the 1990 manual, and 83F, 84F,

85F, 87BB, and 87BB Long Barrel for the 1999 manual. Note that the manuals do

not completely overlap when covering all versions. Both the 1999 firearm manual

that came with another 85 Cheetah and the 1990 one examined in the case did not

state the 85FS in its listing of models covered. Some of the models are similar in

both their handling and safety features. The directions in the manuals exclude or add


features on other models. An example is “half-cock position (only ‘BB’ models).” As the manual is the primary source for safety, this could be confusing.

Another safety feature also was identified—a chamber-loaded indicator. Both

manuals stated:

C2 Chamber-loaded indicator: when the cartridge is in the chamber, the upper surface

of the extractor protrudes and shows red (mod. 87 excluded). In the dark the protrusion

can be felt by touch. It is therefore unnecessary to work the slide to see whether the

barrel is loaded.

Although loaded chamber indicators are an important safety feature, more infor-

mation could have been supplied on preparing the user for their use. The extractor

doubles as a loaded chamber indicator; the red portion that sticks out from the frame

is small and not easily seen when covered by a shadow. Also, practice is needed to

recognize by feel when a cartridge is in the chamber as the small protrusion is easy

to miss (DVD Appendix A, Case 12.1).

Analysis. The poor ergonomic design of both the handgun and the manuals

lend support to the possibility that this was an inadvertent shooting. For example,

with respect to the gun’s design, the fact that the safety lever stopped and felt fully

engaged but was not, and that the gun was capable of firing, appears to be a seri-

ous ergonomic design flaw. Many features of the manuals violate ergonomic design

principles and, accordingly, are confusing, incomplete, and could have contributed

to this being an inadvertent shooting.

193

Appendix B

Additional Information

from a Study of Physics

and Firearm Handling

EFFECTS OF INERTIA ON TRIGGER PULL AND INTENT

Equations for inertia:

E—energy in ft. lbs.M—the weight of the firearm in pounds

V—the velocity of the firearm in ft./ sec.

gc — a unit constant to compensate for the difference between pounds as a measure

of force and pounds as a measure of mass

.

E—energy in ft. lbs.

F—force applied to the firearm

D—distance over which the force is applied

Combining the two equations above and solving for F we get:

Using this equation one can determine the force required to stop a firearm travel-

ing at a known speed. To determine the speed, a series of curves was generated as

shown in Figure B.1.

Average velocity is the constant speed required to move the firearm a specific

distance in a specific time. Not used because the firearm is at a stop at the beginning

and a stop at the end.


Instantaneous stop is a constantly increasing velocity with an instant stop at the end. Not used because it is not possible to stop the object instantly.

Sudden stop is a constantly increasing velocity with a rapid but not instant stop at the end. This example, although the most likely of the options, is too hard to accu-rately predict a model for, and was not used.

Controlled motion is a constantly increasing velocity until the halfway point and then a constantly decreasing velocity until it reaches a stop. This was the model used, as it is both possible and the most conservative.

In addition to the forces resulting from motion of a firearm, shown in Table 10.1

for two widely used handguns, other examples are shown in Table B.1.

EFFECTS OF COUNTERBALANCING FIREARM WEIGHT ON TRIGGER PULL AND INTENT

EQUATIONS FOR BALANCE AND CENTER OF MASS:

Mgravity—weight of the firearm in pounds

X—distance from center of mass to butt in inches

Ft—Force applied to trigger to maintain a level firearm in pounds

Y—distance from the trigger to the butt in inches

Fhandx—force applied to the firearm by the hand parallel to the barrel

Fhandy—force applied to the firearm by the hand perpendicular to the barrel

Table 10.2 in Chapter 10 depicts the trigger force required to hold a firearm level,

based on the above. For a diagram of these variables applied to a firearm, see DVD

B.1. For photographs of the test apparatus used in this study, see DVD B.2.

Controlled motionSudden stop

Average velocityInstantaneous stop

Velocity vs. time

Time (s)

60

50

40

30

20

10

00.30.250.20.150.10.050

Vel

oci

ty (

ft/s

)

FIGURE B.1 Velocity versus time models.

Appendix B: Additional Information from a Study of Physics and Firearm Handling 195

TABLE B.1.

Forces for two common handguns





(lb)


loaded (lb)

0.0909 111.1111 75.7676 230.3333 254.9494

0.1111 90.9191 61.9898 154.1919 170.6666

0.1313 76.9292 52.4545 110.3939 122.1919

0.1515 66.6767 45.4545 82.9292 91.7878

0.1717 58.8282 40.1111 64.5656 71.4545

0.1919 52.6363 35.8888 51.6868 57.2020

0.2121 47.6262 32.4747 42.3131 46.8383

0.2323 43.4848 29.6464 35.2727 39.0404

0.2525 40.0000 27.2727 29.8585 33.0404

Note: Ruger Super Black Hawk 48 oz. 7 ½” BarrelAmmunition: 6 rounds El Dorado Starfire 44 Rem Mag 240 gr. (374 gr. total weight)





(lb)


loaded (lb)

0.09 111.11 75.76 148.75 178.78

0.11 90.91 61.98 99.58 119.68

0.13 76.92 52.45 71.30 85.69

0.15 66.67 45.45 53.55 64.36

0.17 58.82 40.11 41.69 50.11

0.19 52.63 35.88 33.38 40.11

0.21 47.62 32.47 27.32 32.84

0.23 43.48 29.64 22.78 27.37

0.25 40.00 27.27 19.28 23.17

Note: Taurus PT92 31 oz. 4 ¼” Barrel

Ammunition: 15 rounds Winchester 9 mm Luger 115 gr. (182.5 gr. total weight)

197

GlossaryAbbreviatedrules The basic one-sentence NRA rules for safe firearm handling

and safe firearm use and storage without the additional explanation.

Acceptance As used herein, the final emotional stage, which persons hopefully

reach, is acceptance of their action of having shot someone in self-defense.

Action All the moving parts of a firearm that allow it to load, fire, and unload.

Adjustablesights Gun sights that can be adjusted both up and down and right

and left.

Anthropometrics Physical measurements of the body or body parts, such as

strength, reach distances, height, etc.

Anxiety As used herein, an emotional reaction to threat in which one feels

anxious—can result in physiological, perceptual, and cognitive stress

responses.

Approach response A response to threat in which the person confronts the

source, rather than fleeing or avoiding it.

Arcofmovement The circular movement noticed by the shooter in the sights,

caused by holding the weight of the firearm and environmental factors,

such as wind.

Automatic A type of firearm in which squeezing the trigger results in multiple

rounds being fired while the trigger is depressed.

Autopistol Another name for a semiautomatic handgun.

Avoidanceresponse A response in which the person tries to avoid a threat, often

by fleeing the threat situation.

AxisRodorbaseplate A metal rod that goes through a revolver’s frame and the

center of the cylinder so that the chambers rotate to align with the barrel.

Backstrap The metal strip that is at the rear of the frame where the hand is

placed on the grip, usually part of the handgun’s frame.

Barrel One of the three basic components of a firearm: the metal tube that the

projectile passes through, providing direction for the projectile.

Barrel(s),frame,andaction The three basic components of any firearm.

BasicPistolMarksmanship(BPM) Original 1959 NRA marksmanship course;

replaced by the 1991 Basics of Pistol Shooting (BPS).

Basics of Personal Protection (BPP) course Original 1988 NRA personnel

protection course; replaced by the NRA’s 2000 Personal Protection in the

Home (PPIH).

BasicsofPersonalProtectionOutsidetheHome(PPOH) A new NRA course.

The course manual was issued in 2006. Prepares persons for concealed

carry, including handgun safety.

BasicsofPistolShooting(BPS) The current NRA marksmanship course; in

1991 it replaced the NRA’s 1959 BPM course.

Bayonet A dagger that connects to the muzzle of a musket or rifle.


Beltedcartridge A cartridge with an extra belt of metal around the base and above the extractor groove.

Benchrestposition A shooting stance where the shooter is sitting down and the handgun is supported by placing the wrists on sandbags, which are stacked and sitting on a bench or table.

Berdan priming system A center fire type of priming system in which the

anvil is part of the cartridge case. The world standard system outside the

United States.

Biomechanicalpositioning The positioning of the body when shooting a firearm.

Blackpowder A flammable used in older ammunition to fire the projectile; typi-

cally comprised of saltpeter, charcoal, and sulfur.

Blanks Cartridges that contain gunpowder but have no projectile.

Bloodalcoholcontent(BAC) BAC is expressed as a percentage and is equal to

100 times the mass of the alcohol per mass of blood. Thus, 1 part alcohol

per 1,000 parts blood is equal to a BAC of 0.1 percent.

Bloodpatternanalysis Analysis of blood patterns at a shooting scene to help

determine what happened and where.

Bloodpatternexpert A person professionally trained to recognize the individ-

ual stains and patterns to provide specific clues as to what happened and

where.

Blowbacksystem A semiautomatic operating system that takes the gas pressure

created in the chamber from the combustion of the gunpowder and uses it

directly by pushing the cartridge back against the slide to work the action

(i.e., to fire, eject, cock, reload, and close the action of the handgun).

Blowforwardsystem A semiautomatic operating system in which the breech

does not move but the barrel moves forward.

Board of Certification in Professional Ergonomics (BCPE) The national

professional certification board for human factors and ergonomics profes-

sional practitioners officially endorsed by the International Ergonomics

Association. The BCPE maintains an online listing of its certificants.

Bombard An early form of European cannon, which primarily was used for

sieges.

Borediameter The inside diameter of a firearm’s barrel.

Boxerprimingsystem A center fire type of priming system in which the anvil

is part of the primer. The United States standard system.

Breathcontrol As used herein, controlling one’s breath while shooting to gain

accuracy. It involves first exhaling, then inhaling a fresh breath of air until

the amount of air in the chest feels relatively comfortable, and then hold-

ing that position and firing.

Breechface The portion of a revolver’s frame that is against the cartridges and

supports them in the chambers.

BrownBess A British flintlock musket. The most famous of all the flintlocks.

Bullet The projectile portion of a cartridge.

Bullpuprifles A rifle designed for military use that has the action behind the trig-

ger, making for a short overall length while retaining a full-length barrel.

Glossary 199

Bullseyetarget A target consisting of a black circle of a known diameter on white or light-colored background paper.

Butt The bottom part of the grip or grip frame of a firearm.

Caliber A nominal dimension; the approximate diameter of a cartridge’s projec-

tile or bullet; it can be measured in millimeters or inches.

Caplock A firing mechanism that replaced the flintlock during the first half of

the 19th century. It yielded a much faster ignition than the flintlock.

Caracole An early 16th-century tactic in which the first rank of a cavalry unit

would fire their pistols, then retire to the rear of the formation to reload

while the second and subsequent ranks repeated the process to keep up

continuous fire on an infantry formation.

Carbine A scaled-down version of a full-sized rifle with greater range and accu-

racy than a pistol. The M-1, which fired a “super pistol” cartridge, is per-

haps the best known.

Carroballistae Small dart shooters mounted on carts used by ancient Romans.

Cartridge The complete piece of firearm ammunition, consisting of four basic

components: the case, projectile, powder charge or propellant, and primer.

Cartridge canneluree Rolled groove on the cartridge case that supports the

projectile from being pushed farther into the case by the force of recoil.

Cartridge case A cylinder closed at one end that acts as the packaging that

holds the other components of the cartridge in place.

Cartridgecrimp The pushing of the case mouth into or against the projectile to

hold the projectile firmly in place.

Cartridge extractor groove The cut into the body above the rim to aid in

extraction.

Cartridgeflashhole The hole cut through the base that allows the sparks from

the primer to reach the gunpowder/propellant.

Cartridge head The base of the case, including the rim, extractor groove,

primer pocket, and web.

Cartridgemouth The opening at the top of the case where the projectile is seated.

Cartridgeneck The top portion of the case, clearly visible on a bottlenecked

cartridge above the shoulder.

Cartridgeprimerpocket The area cut out of the base to allow for insertion of

the primer.

Cartridge shoulder The sloped portion below the neck on a bottlenecked

cartridge.

Cartridgeweb The thin metal separating the main chamber of the case from

the primer pocket around the flash hole.

Cerebralcortex The brain structure where all mental activities such as plan-

ning, analyzing, reasoning, and decision making occur. It is the large,

folded gray portion of the brain that covers the other brain structures.

Chamber The opening at the loading end of the barrel that holds and supports

the cartridge in single-shot and semiautomatic firearms. Revolvers and

multiple-barrel firearms have multiple chambers. Each chamber can hold

one cartridge.


Chin The part of the frame forward of a revolver’s trigger guard that is curved upward.

Chronicstress Stress that continually is with a person; most often in the form of either self-induced lifestyle stress or residual stress, or a combination of the two.

Classcharacteristics The diameter of the bore, number of lands and grooves, dimensions of lands or grooves, as well as direction of twist (left or right) of these lands and grooves. Many firearms made by the same manufacturer, and

sometimes by other manufacturers, have these same specific dimensions.

CodeofForensicPractice The official forensics practice code of the Human Fac-

tors and Ergonomics Society; it is Article V of the Society’s Code of Ethics.

Cognitiveresponse A mental or thought response to a situation or event.

Conoidbullets A bullet invented during the 1900s that had much better exterior bal-

listic performance from rifled barrels than the round ball that they replaced.

Cornedpowder A form of gunpowder. Black powder that first was moistened

and worked into dough, then dried and ground to a specific size. It is more

powerful than ordinary black powder.

Costofcompliance The effort required to comply with a rule or directive, such

as a safety rule or requirement to wear a piece of safety equipment.

Crane The part of a revolver that allows the cylinder to swing out to facilitate

loading and unloading.

Crown The physical portion of the barrel of a gun surrounding the opening.

Culverin A medium-sized, direct-fire early European cannon, primarily used

for sieges.

Culverinàmain Also called a hand cannon or hand gonne. The first European

handheld firearm. It appeared in Europe around 1364. It was simply a tube

of metal with one closed end, which was attached to a portion of a wooden

pike shaft.

Cupandsaucerhold A handgun grip that involves placing the base of the hand

and bottom of the grip on the palm of the nonshooting hand.

Cyclicstress A form of self-induced lifestyle stress, which is imposed by situa-

tions that occur on a predicatable and recurring basis.

Cylinder The part of the revolver that contains multiple chambers and rotates

(revolves) in the frame.

Cylindergap The gap between a revolver’s cylinder and barrel that allows the

cylinder to rotate without rubbing against the barrel.

Cylinderrelease A release latch for a revolver’s cylinder to unlock it from

the frame.

DanishMadsen A light machine gun used by Russian cavalry in the Russo-

Japanese war.

Daubertv.MerrellDowPharmaceuticalsInc. The U.S. Supreme Court case

that defined the boundaries for acceptable expert testimony.

Deathgripping Gripping a handgun too tightly, thus restricting oxygen transfer

to the hand and finger muscles.

Decocker A lever found on some semiautomatics that decocks the hammer

without discharging the firearm.

Glossary 201

Design-inducedhumanerror When human error is caused by the design of a tool, machine, software, etc. exceeding human capabilities and limitations.

Discharge The firing of a bullet or other projectile from a firearm.

Distortedperception As used herein, an emotional/cognitive response in which

what one fears to be the case in the situation is what one actually perceives

or sees, when actually it is something else.

Divided attention When one attempts to consciously attend to two or more

things at once.

Double-actionfirearm One in which all the parts are moved into place to fire

by a single pull of the trigger.

Dragoons Mounted infantry.

Dummycartridge A cartridge that has no powder charge or primer.

Ejectionport The opening in a semiautomatic’s slide that allows cartridges or

casings to be ejected.

Ejector The part of a firearm that extracts the cartridge.

Ejectorhousing An elongated metal housing that guides and protects the ejec-

tor rod.

Ejectorrod Also called the extractor. A metal rod that protrudes from the cen-

ter front of a revolver’s cylinder, through the cylinder, attaching to the

extractor or ejector.

Elation As used herein, a common emotional reaction by a person who has had

to shoot an intruder or attacker in self-defense that sometimes mistakenly

is interpreted as the person being happy about the shooting.

Environmentalstress Stress resulting from one’s physical environment, such

as high noise levels, temperature extremes, excessive humidity, vibration,

glare, inadequate illumination, etc.

Ergonomics Also known as human factors, it is the scientific discipline that

studies human capabilities, limitations, and other characteristics, and

applies that knowledge to the design of tools, machines, systems, tasks,

jobs, and environments for productive, safe, comfortable, and effective

human functioning.

Ergonomics in Design A practitioner-oriented professional magazine, pub-

lished quarterly by the Human Factors and Ergonomics Society.

Extractor Also called the ejector rod. The part of a revolver that extracts the

cartridge or casing.

Eyedominance The eye a person primarily depends on for vision; important in

use of firearms in that one should always shoot from the side of the domi-

nant eye (i.e., right-handed for right eye dominance, and vice versa).

Falsenegatives Something is categorized as not happening, when, in fact, it did.

As used herein, shootings categorized as “not intentional” when, in fact,

they were.

Falsepositives Something is categorized as happening when, in fact, it did not.

As used herein, shootings categorized as “intentional” when, in fact, they

were not.


Fatigue As used herein, a condition brought about by a lack of sleep or stress, which not only may result in feelings of tiredness and/or being worn out but in dysfunctional physiological and behavioral effects.

Fear An emotional reaction to threat that can result in physiological, perceptual, and cognitive stress responses.

Fight or flight physiological alert response The sympathetic-adrenal med-ullary neuroendocrine system activates, increasing one’s strength and causing the individual to tense his or her muscles. Included are increased heartbeat, labored breathing, and trembling.

Fingerprintanalysis The study and comparison of high points on the skin, called friction ridges, usually from the last joint to tip of the finger and thumb.

Fingerprintrecognitionaccesssystem A smart gun system under development

that uses a computer chip that recognizes the intended user’s fingerprint in

order for the gun to operate.

Firearm Any type of gun, including handguns, rifles, shotguns, machine guns,

etc.

Firearmidentification Comparing firearm parts to marks left on cartridge casings

or bullets, or bullet/casing to bullet/casing. Results usually are expressed as

exclusion/eliminations, inconclusive, or identifications (matches).

Firelances Spears with attached bamboo containers of powder developed by the

Chinese. They were designed to shoot flames at the enemy.

Firingpin Also called a striker. Usually a metal rod that is attached to the face

of the hammer or in the frame of the firearm at a place where the hammer

can contact it. It transfers force to the ignition system of the cartridge.

FIRSTStepsorientationcourses Model-specific courses that teach only the

most basic shooting skills; they are not complete courses in the traditional

sense of the word.

Fixedsights Gun sights that are not adjustable; typically found on small firearms.

Flashpan The part of a matchlock or flintlock gun that holds a small amount of

powder, which primes the charge when ignited.

Flint The part of a flintlock firing mechanism that strikes the frizzen, creating

sparks into the gunpowder, thereby igniting the priming charge.

Flintlock A firing mechanism invented in France in 1610. When the trigger is

pulled, the hammer releases under spring pressure, striking the flint against

a piece of steel called the frizzen. This creates a shower of sparks into the

gunpowder in the flash pan and thereby ignites the priming charge.

Flutes The area cut out of the front sides of the revolver’s cylinder to reduce

weight or for decorative purposes.

Follow-through The act of holding the front sight in alignment with the rear

sight correctly on the target until the recoil pushes the sight off of the

target.

Forcingcone A funnel cut into the rear portion of a revolver’s barrel that allows

the projectile to be funneled into the barrel.

Forensicpathologist The expert in shooting cases who can provide information

such as time of death, cause of death, entrance, exit, and direction the pro-

Glossary 203

jectile traveled, and potential for deflection in the body of the projectile, as well as identifying items of evidentiary value.

Forensics The art or study of legal proceedings.ForensicsProfessionalGroup(FPG) A professional entity of the Human Factors

and Ergonomics Society. The FPG serves to provide a scientific and tech-

nical focus on issues being interpreted by legal theory and procedures.

Frame The part of the firearm that holds all the other parts together, allowing

them to function correctly.

Frizzen The part of a flintlock firing mechanism that is struck by the flint.

Frontsight The forward-aiming point on the front of the barrel of a gun.

Frontstrap The metal strip on a handgun that is in the front of the frame where

the hand is placed on the grip, usually part of the frame.

Fullmetal jacket A projectile in which the lead core is inserted into a pre-

formed hard metal jacket, leaving only the projectile’s base exposed. If the

base also is encased, it is called a total metal jacket.

Fundamentals As used herein, the proper use of the body as a carrying and firing

platform. There are six basic fundamental issues when shooting: grip, stance,

breath control, sight alignment, trigger control, and follow-through.

Garand Adopted in 1937, it was the first widely issued military semiautomatic

rifle. It fired the powerful .30-06 cartridge and employed eight-round en

bloc clips. The current U.S. M-14 is directly descended from the M-1

Garand.

Gas-operatedsystem A fairly uncommon semiautomatic operating system that

functions by siphoning off gas from a small hole in the barrel and divert-

ing it, usually through a tube, to operate the bolt or slide.

Glasersafetyslug A type of novelty projectile.

Grip(s) The handle of a firearm.

Gripcocking A system designed to prevent young children from operating the

firearm; considerable pressure must be exerted on the grip to enable the

handgun to fire.

Grippatternrecognitionaccesssystem A smart gun system under develop-

ment that recognizes the unique grip pattern of the intended user, which

enables the gun to fire.

Gunpowder A flammable used in ammunition to fire a projectile.

Gunshotresidue(GSR) In the forensic scientific community, it is a name for

a compound created primarily by the primer during the ignition process.

This submicroscopic compound will consist of lead (pb), barium (ba), and

antimony (sb) and may have other elements as well. In reality, all residues

from the cartridge being fired are GSRs (i.e., soot, partially burned and

whole gunpowder particles, and lead and copper residues).

Gunshotresidue(GSR)testing Analysis of GSR to aid in determining who

fired a shot from a gun, as the GSR compound will adhere to surfaces with

which it comes in contact, such as the clothing, hands, and face.

Gun vaults Vaults for securely storing handguns and ammunition. They are

designed to be opened by key, combination lock or keypad, or padlock.


Hammer The part of the firearm firing mechanism that provides force to ignite

the primer.

Hammerless A handgun on which the hammer is not visible is said to be

hammerless.

Hammerspur A protrusion at the rear of the hammer. It aids in manually cock-

ing the firearm with one’s thumb.

Hand Also called a pawl. An internal part that protrudes from a rectangular

opening, called a window, in the breech face that engages the ratchet to

rotate a revolver’s cylinder.

Handed standing position A standing shooting stance in which the shooter

holds the handgun with just one hand.

Handgun A type of firearm that can be held in one hand and fired. The two

common types are semiautomatics and revolvers.

Hangfire A perceptible delay in the ignition process. When the trigger is pulled

there is a felt moment of time in which nothing happens, then the car-

tridge fires.

Headstamp Information stamped into the base of a cartridge that may identify

caliber, manufacturer, factory codes, date of manufacture, or other infor-

mation about the cartridge.

Houfniceorhaufnitze The precursor to the modern howitzer. It had a short bar-

rel and a bore diameter on the order of 8 to 12 inches and was mounted on

a two-wheeled carriage.

HumanEngineeringDesignCriteriaforMilitarySystems,Equipment,and

Facilities(MIL-STD-1472) A significant resource for military and non-

military system designers for over 30 years.

Human-environment interface technology That portion of human-system

interface technology concerned with the design of the physical environ-

ment (e.g., illumination, temperature, noise control, vibration control).

Humanfactors Also known as ergonomics, it is the scientific discipline that

studies human capabilities, limitations, and other characteristics, and

applies that knowledge to the design of tools, machines, systems, tasks,

jobs, and environments for productive, safe, comfortable, and effective

human functioning. The application of human factors also is known as

human factors engineering.

Human Factors A distinguished scientific journal, published by the Human

Factors and Ergonomics Society.

Human Factors and Ergonomics Consultants Directory A publication of the

Human Factors and Ergonomics Society; a good source for finding human

factors and ergonomics professionals who serve as expert witnesses and/

or forensics consultants.

HumanFactorsandErgonomicsSociety The national scientific and profes-

sional society for the human factors and ergonomics discipline. Head-

quartered in Santa Monica, California, it has about 5,000 members.

Human Factors and Ergonomics Society Directory and Yearbook An annual

publication of the Human Factors and Ergonomics Society. Members of

Glossary 205

the society’s Forensics Professional Group have the letters FP following their address.

Human-jobinterfacetechnology That portion of human-system interface tech-nology that deals with designing jobs to ensure that workload is appropri-ate and that jobs are intrinsically motivating and harmonized with the overall work system.

Human-machine interface technology That portion of human-system inter-face technology concerned with the design of human-machine interfaces (e.g., consumer products, and workstation controls, displays, seating, and workspace arrangements).

Human-organization interface technology That portion of human-system interface technology concerned with the overall design of work sys-tems—the technology of the human factors or ergonomics subdiscipline of macroergonomics.

Human-softwareinterfacetechnology That portion of human-system inter-face technology concerned with the design of human-software interfaces (i.e., designing software so it functions the way people think and process information).

Human-systeminterfacetechnology(HSIT) The technology developed from the study of human capabilities, limitations, and other characteristics that is applied to the design of tools machines, systems, tasks, jobs, and environments for productive, safe, comfortable, and effective human and functioning. HSIT takes the form of design principles, guidelines, specifi-

cations, methods, and tools.

Humanoid targets Targets generally configured and sized in the shape of a

human being, typically a black silhouette on a white background.

Huntersafetycourses Typically 12-hour courses that address topics, such as

survival skills in the wild, hunter ethics, animal identification, etc., and

are not primarily a firearms safety course, yet sometimes are treated as

such for obtaining a concealed handgun permit.

Inadvertentdischarge When a gun fires a projectile that was unintended or

involuntary on the part of the shooter.

Inadvertentshooting When a person is shot and it either was involuntary and/

or the discharge was not intentional by the shooter.

Inbattery A semiautomatic is in battery when a cartridge is in the chamber and

the slide or bolt properly closed on the cartridge.

Instructional system development (ISD) A formal systematic process for

developing effective training programs.

InternationalErgonomicsAssociation(IEA) The international federation of

national and regional human factors and ergonomics societies, represent-

ing over 50 countries.

Involuntarydischarge When a person squeezes the trigger of a firearm as a result

of involuntary muscle contraction, such as might occur as a startle response.

Involuntary shooting When an involuntary discharge results in someone

being shot.


Isoscelesposition A handgun standing shooting stance. An isosceles triangle is created by holding the handgun out with the two arms fully extended, both arms approximately the same length, with the back and shoulders forming the third side of the triangle.

Key-lockingaccesssystem A lock is embedded in the handgun, which must be unlocked with a key in order for the gun to operate.

Keypadentryaccesssystem A keypad is embedded in the side of the handgun. The user’s personal code must be entered for the gun to operate.

Kinestheticsense Perceptual feedback about body part position and changes in position from receptors in our muscles, tendons, and joints.

Landsandgrooves High points (lands) and low points (grooves) cut into the inside of a firearm’s barrel in a twisting direction.

Latentprints Fingerprints not visible to the naked eye.

Loadingdevice Any device that can be attached to a cartridge to alter its shape

to work in a different firearm.

Loadinggate A hinged part attached to the frame behind a revolver’s cylinder

that is opened to allow loading, and closed to keep the cartridges in place

when the cylinder is rotated during firing.

Lock boxes Boxes for securely storing handguns and ammunition. They are

designed to be opened by key, combination lock or keypad, or padlock.

Locknotches Small arrow-shaped notches that are cut into the rear of a revolv-

er’s cylinder. When the lock or bolt engages the lock notches, the cylinder

is held in the correct place for alignment with the barrel.

Lockorbolt A part that comes through the frame under a revolver’s cylinder to

engage notches in the cylinder in the correct position for firing.

Lock,stock,andbarrel A term meaning a complete firearm.

Locked breach system The most common semiautomatic operating system.

When the firearm is fired, the barrel is locked to the slide. As the projec-

tile is pushed out of the barrel, the gases are also pushing the cartridge

case against the breech face of the slide and, therefore, the slide is pushed

to the rear. The barrel travels a small distance back with the slide until the

pressures drop to a safe level. At this point, the barrel drops down, unlock-

ing itself from the slide and staying with the frame. The slide continues

its travel rearward completing the extraction, ejection, reloading, cocking,

and closing process (cycling).

Macroergonomics A subdiscipline of human factors or ergonomics that is con-

cerned with the overall design of work systems.

Magazine A container designed to hold ammunition in semiautomatics. It gen-

erally has four parts: the body, floorplate, follower, and internal spring.

Magazinerelease A lever that, when activated, will unlock the magazine from

the semiautomatic handgun.

Magazinewell The place that a magazine is inserted into a semiautomatic hand-

gun. It usually is located in the grip.

Magnetic access system This system requires the intended handgun user to

wear a ring with a tiny magnet embedded in the bottom in order for the

firearm to operate.

Glossary 207

Magnetic electric access system Also known as a solenoid use limitation

device, it involves a magnetically activated solenoid. As with the magnetic type, a magnetic ring is worn by the user, which in this case activates the solenoid to unblock the firing mechanism.

Mainspring A leaf or coil spring that powers a revolver’s hammer, allowing

it to move forward with force enough to cause the ignition system in the

cartridge to function.

Marksmanship The ability to properly handle a gun and shoot accurately.

Matchlock A type of gun that was commonly used in Europe from the mid-

1400s until the early 1700s. The matchlock arquebus was one of the first

and simplest firing mechanisms to be developed that employed a flash

pan.

Methamphetamines Also known as shards, rock, pony, crystal, glass ice, dev-

il’s dandruff, and, in less pure form, as crank or speed, or in crystalline

rock form as dope. A highly addictive, very potent central nervous system

stimulant that affects the brain by acting on mechanisms responsible for

regulating a class of neurotransmitters known as the biogenic amines or

monoamine neurotransmitters. It initially can cause feelings of euphoria,

which motivates people to take it, but also results in paranoia, depression,

long-term cognitive impairment due to neurotoxicity, psychosis, and hos-

tile, aggressive behavior.

Misfire Failure for the cartridge to work at all. When the trigger is pulled on a

properly working firearm, nothing happens.

Moonclip A type of loading device that attaches to the .45 auto cartridge at the

extractor groove to allow for the cartridge to be used in a revolver.

Muzzle The end of the barrel where the projectiles come out.

Muzzleend The front end of a firearm.

Muzzleloaders Guns in which the powder and bullet have to be inserted through

the muzzle.

Narrowed attention When a person’s attention becomes narrowly focused,

such as on the source of threat in a highly stressful situation. Sometimes

referred to descriptively as tunnel vision.

Negativetransferoftraining When a learned way of performing a given task

differs from the way the task actually needs to be performed, thus result-

ing in the person performing the actual task in the incorrect, previously

learned way. This most often occurs when the nature of the task has been

changed, such as from redesign of a display or control. It is a major cause

of design-induced human error.

Noveltyprojectiles Nontypical projectiles that expand in nontraditional ways.

NRArulesforsafefirearmhandling The rules published by the National Rifle

Association are: Always keep the gun pointed in a safe direction, always

keep your finger off of the trigger until ready to shoot, and always keep

the gun unloaded until ready to use.

NRA rules for safe firearm use and storage The eight rules specified and

explained for these two purposes published by the National Rifle

Association.


Occupationalstereotype A stereotypical or habitual way of performing a given task.

Openbookexam An exam in which the test taker is allowed to look up the answers to questions in his or her textbook or similar training materials.

OxfordResearchInstitute(ORI) A U.S. institute that offers professional cer-tification in human factors and ergonomics.

Pawl Also called a hand. An internal part that protrudes from a rectangular

opening, called a window, in the breech face that engages the ratchet to

rotate a revolver’s cylinder.

Perception That which we perceive from our various receptors, such as those

for vision, hearing, kinesthetic feedback, touch, smell, etc.

Performancerigidity The tendency to continue behaving in the same way, even

when there are clear indications that it is not effective.

Peripheralcues Cues that lie outside the focus of one’s attention. For example,

in a threat situation, the location of one’s trigger finger and the direction

one is pointing a handgun while focused on the source of threat in a highly

stressful situation.

PersonalProtectionintheHome(PPIH) The current NRA personal protec-

tion course.

Personalizedaccesssystems Systems internal to firearms that enable use only

by authorized persons.

Physiologicalstress The physiological responses of the body to threat.

Pistols A handgun that does not have a cylinder but may have a multitude of

barrels.

Potdefer A vase-shaped gun mounted on a trestle and firing an arrow. May be

the earliest form of artillery.

Prawl The bend in the frame at the rear of a revolver and above the grip.

Pressure plates The protrusion from the frame behind the cylinder of a

revolver that supports the cartridge, keeping them from falling out of the

chambers.

Priming Anticipating a particular contextual situation as a result of a briefing,

etc., increasing the likelihood of perceiving the actual situation the same

way, even if it is not.

ProceedingsoftheHumanFactorsandErgonomicsSocietyAnnualMeet-

ing The CD that contains the papers and other presentations presented

at the society’s annual scientific and professional conference (formerly

published in standard book form).

Projectile The bullet or portion of the cartridge that is propelled from the car-

tridge and that may impact a target, person, or other object.

Projectilebase The bottom portion of the bullet; may be enclosed by a jacket or

open, exposing the lead core.

Projectilebearingsurface The walls of the projectile that contact the rifling.

Projectilecannelure A groove cut around the projectile, either smooth or ser-

rated; may be used for holding lubrication or to allow the mouth of the

case to be crimped tightly to the projectile.

Projectilecore The internal portion of the projectile normally made of lead.

Glossary 209

Projectilejacket The hard metal covering over the core. Common jacket metals are copper, brass, steel, or aluminum.

Projectileheel The base portion of the bullet behind the bearing surface; it may be cylinder shaped (square or flat base) or boattail (taper heel).

Projectilemeplet The diameter of the blunt end of the tip of the bullet.Projectile ogive All of the bullet forward of the bearing surface; it may be

curved, rounded, or pointed.Propellant The part of the cartridge that actually propels the bullet or projec-

tile; smokeless gunpowder in most modern cartridges.Push/pullhold A handgun grip in which the fingers, wrapped around the for-

ward portion of the grip, are pushed into a cupped support hand.

Quick loaders Also called speed loaders, these are devices for reloading

revolvers quickly.

Radio frequency identification (RFID) access system A close-range radio

wave from a wristband or other emitter worn by the user is received by

a microchip inside the gun’s grip, which causes a tiny aerospace stepper

motor to activate the firing mechanism. Firearms equipped with RFID are

called smart guns.

Ratchet The part of the ejector in a revolver, shaped like a notched wheel, that

rotates the cylinder when pushed by a part called the hand or pawl.

Reactiontime The time between when an event occurs and the person initiates

a response to it.

Rearsight The aiming point on the rear end of the barrel or top of the frame

(receiver) at the rear end of the firearm.

Rebatedcartridge A cartridge with a rim that is less then the diameter of the

walls of the case and extractor groove.

Recallinterference Activities conducted after performing some other activity

interferes with the ability of the person to recall the original activity.

Recoil The equal and opposite energy reaction of the firearm in response to the

discharge of the bullet.

Reconstructionist The term given to those having forensic training, knowl-

edge, and experience in more than one discipline. A reconstructionist puts

together information from multiple disciplines that provide a factual basis

as to what events took place, and in what order, based on scientific inves-

tigation and evidence.

Refresher training As used herein, a short training program administered

some time after the initial training in handgun marksmanship and safety

to refresh one’s knowledge and skills.

Remorse As used herein, a normal feeling of sadness to having been forced to

kill someone in self-defense. It sometimes is misinterpreted as the person

feeling guilt over having shot someone unjustifiably.

Residualstress The emotional baggage one carries around from one’s child-

hood; stress resulting from guilt, feelings of inadequacy, anger, etc. that

one picks up in the process of growing up.

Responsetime The time between when an event occurs and a person completes

a response to it.


Reticular Activating System (RAS) The portion of the brain that arouses the cerebral cortex so that it can pay attention and carry on its various mental activities.

Revolver A type of handgun characterized by a rotating cylinder that holds the ammunition.

Revolver,singleaction One in which the hammer must be manually cocked to fire.

Ribaudequin Also known as ribald or organ gun. A type of artillery used dur-

ing the first half of the 15th century. It consisted of multiple small-bore

tubes mounted on a cart.

Rimfirecartridge A cartridge in which the primer is in the rim; the firing pin

must strike the rim to cause ignition.

Rimlesscartridge A cartridge with a rim that is even with the outside dimen-

sions of the case.

Safety A mechanical device that is designed to prevent a firearm from discharging.

Scenedocumentation The first and most critical step in the investigation of a

shooting incident is documentation of the scene and location of potential

evidence. Documentation can be done by photographs, video recording,

sketching, and notes.

Self-doubt As used herein, the feeling that may accompany remorse, wondering

if there is not some way one could have avoided killing the person who

threatened him or her.

Self-inducedlifestylestress A form of chronic stress that is caused by the life-

style a person chooses to live (e.g., working too hard, failing to get enough

sleep, etc.).

Semiadjustablesights Gun sights can be moved left and right for windage but

have no elevation adjustment.

Semiauto A commonly used nickname for semiautomatic handguns.

Semiautomatic A handgun that uses the gasses created by the ammunition

combustion process to do work. One projectile is fired each time the trig-

ger is pulled.

Semijacket A projectile in which the lead core is partially jacketed by a harder

material; they typically are designed to provide for controlled expansion.

Semirimmedcartridge A cartridge that has a base with a rim that protrudes

slightly out from the body of the case and an extractor groove.

Serpentine A curved piece of metal on matchlock guns to which a “match” cord

soaked in nitrates was attached. When released, it dropped the glowing

match to the flash pan, igniting the priming charge.

Shooting An event where someone is hit by a projectile discharged from a firearm.

Shotgun A gun that fires a charge of shot or small pellets.

Sightalignment Aligning the gun sights with the target, such that the top of

the front sight is level with the top of the rear sight and the front sight is

centered in the slot of the rear sight.

Single-shot,single-barrelhandguns Handguns that only allow for one shot to

be fired, and the process of removing (extracting and ejecting) the fired

cartridge case and loading a new cartridge must be completed in order to

fire the next shot.

Glossary 211

Single-shot,-multibarrelhandguns These handguns have many of the same parts as the single shot above, but with multiple barrels and chambers.

Sixo’clockhold A sighting on a bullseye target where the bottom of the circle rests on top of the aligned front sight (i.e., on the six o’clock position of the circle).

Slide The upper portion of most semiautomatics that reciprocates (slides) back and forth.

Slidelockorrelease On some semiautomatics, a lever that allows the slide to be locked back.

Smartcardaccesssystem A smart gun system under development that uses an intelligent device with a computer chip that looks much like a traditional credit card.

Smartguns Firearms equipped with a radio frequency identification (RFID) access system.

Smokelesspowder Gunpowder that, when ignited, produces less smoke than black powder.

Solenoiduselimitationdevice See magnetic electric access system.Solidframerevolver Revolvers that have a top strap.Speedloaders Also called quick loaders, these are devices for reloading revolv-

ers quickly.Squib load A malfunction in which insufficient pressure is developed by the

cartridge to dispel the projectile.

Stance The position a shooter takes to provide a stable platform for the firearm

during the firing process.

Startle reaction A whole-body, reflex-like response, most often to an unex-

pected loud noise, but also can be evoked by unexpected visual or other

stimuli (e.g., electric shock, bee sting, etc.).

Stippling The term for when the gunpowder hits the skin creating a wound, but

falls off. It can be an indication of the gun muzzle being near the skin

when it was fired.

Stress The physiological, cognitive, and emotional responses caused by a threat

or other stressful situation.

Stria Striations or parallel scratches on a projectile caused by small imperfec-

tions in a firearm’s barrel from the machining process. Stria can help iden-

tify a specific firearm as having fired a specific projectile.

Striker Also called a firing pin. Usually a metal rod that is attached to the face

of the hammer or in the frame of the firearm at a place where the hammer

can contact it. It transfers force to the ignition system of the cartridge.

Strongisoscelesposition Also known as the modified isosceles, it is a standing

shooting position. It is the same as the standard isosceles position except

that the nonfiring side foot is placed forward of the firing side foot.

Sympatheticcontraction Also called mirror movement or contralateral irradia-

tion, it is the phenomenon where, when the muscles in one limb are per-

forming an intended forceful action, involuntary contraction will occur in

the muscles in the other limb.


Sympatheticdischarge A phenomenon in which two shooters are concentrat-ing on aiming at a target, one fires, and the shock/interruption/tensing of

the other shooter causes him to shoot also, usually very inaccurately.

Tang The pointed portion at the end of the frame and above the grip on a semi-

automatic handgun, similar to the prawl on the revolver.

Tarasnice Enlarged European hand cannons of roughly a 2-inch bore. They

initially fired from a platform with a two-legged stand, with wheeled ver-

sions appearing around 1430.

Tattooing The term for when gunpowder impacts and is retained in the skin. It

is an indication of the gun muzzle being near the skin when it was fired.

Terco A 16th-century military formation comprised of a large square of pike-

men with smaller blocks of arquebusiers at each corner.

Toolmarkevidence The matching of a firearm to a specific bullet or fragment

of a bullet by matching a bullet, known to come from a specific firearm,

to a questioned bullet/fragment.

Topstrap A piece of metal bridging the front part of a revolver’s frame to the

frame’s rear to provide strength to the frame.

Totalmetaljacket A projectile in which the lead core is inserted into a pre-

formed hard metal jacket, which covers the entire projectile. If the bottom

of the lead core is exposed, it is called a full metal jacket.

Traceevidence The forensic science that deals with small, usually microscopic

particles, which may associate a particular person to the scene, victim, or

weapon. Hair, fiber, seeds, pollen, metal shavings or filings, and starch

crystals are examples.

Trigger The part of a firearm that is manually moved to cause the firearm

to discharge.

Triggercontrol Ability to control the movement of the trigger. It is a function

of both the mechanical aspects of the mechanism, such as the trigger force

and movement distance to fire, and human issues, such as hand and finger

size and strength, emotional state, and smoothness of the finger pull.

Triggerguard A part of the frame that goes around the trigger to prevent acci-

dental discharge when dropped and to protect the trigger.

Triggerlocks Devices that encase the trigger portion of the handgun and must be

unlocked by a key, combination lock, or keypad in order to shoot the firearm.

Unintentionaldischarge When a person unintentionally squeezes the trigger of

a firearm, thus causing the firearm to discharge a projectile.

Unintentionalshooting When the unintentional discharge of a firearm causes

the projectile to strike a person.

Voicerecognitionaccesssystem A smart gun system under development that

uses voice recognition technology. The intended user’s voice enables the

gun to operate.

Volcanic The first practical repeating pistol using a cartridge. Invented in 1854

by Americans Horace Smith and Daniel Wesson.

Weaverstance A standing firing position in which the body is perpendicular to

the target, allowing for less exposure to threats.

Glossary 213

Wheellock A firing mechanism, which appeared in 1510, that is similar to that

of modern cigarette lighters. It was an improvement over the matchlock.

Window An opening in the breech face of a revolver, usually rectangular in

shape, that allows for contact of the hand with the ratchet on the ejector/

extractor to rotate the cylinder.

Workload As used herein, the physical, perceptual, and emotional demands

resulting from the tasks that a person is required to perform at a given

time.

215

ReferencesAmerican Academy of Pediatrics. (2000, April). Firearm-related injuries affecting the pedi-

atric population. Pediatrics, 5, 288.American Psychological Association. (n.d.). Of men and machines, Engineering psychology (film:

APA Focus on Behavior Series). Washington, DC: American Psychological Association.

Aranyi, Z., & Rosier, K. M. (2002). Effort-induced mirror movements. A study of transcal-

losal inhibition in humans. Experimental Brain Research, 145, 76–82.

Barnes, F. C. (2003). Cartridges of the world, 10th edition. Northbrook, IL: DBI Books, p.

322.

Beers, M. H., & Berkow, R. (Eds.). (2003). Merck manual of diagnosis and therapy (17th ed.).

Merck Publishing.

Bisdorff, A. R., Bronstein, A. M., & Gresty, M. A. (1994). Responses in neck and facial

muscles to sudden free fall and a startling auditory stimulus. Electromyography and

Clinical Neurophysiology, 93, 409–416.

Black, J. (2002). European warfare, 1494–1660. New York: Routledge.

Board of Certification in Professional Ergonomics. (1999). Candidate handbook: Certifica-

tion policies, practices & procedures (4th ed.). Bellingham, WA: Board of Professional

Certification in Professional Ergonomics.

Brown, P. (1995). Physiology of startle phenomena. In S. Fahn, M. Hallett, H. O., Loders,

& C. D. Marsden (Eds.), Negative Motor Phenomena (pp. 273–287). Philadelphia:

Lippincott-Raven.

Brzezinski, R. (1993). The army of Gustavus Adolphus 2 cavalry. London: Osprey.

Chapanis, A. (1988). To communicate the human factors message you have to know what the

message is and how to communicate it. Keynote Address to the HFAC/ACE Confer-

ence, Edmonton, Alberta. [Also reprinted in the Human Factors Society Bulletin, 1991,

34(11), 1–4, part 1; 1992, 35(1), 3–6, part 2].

Coma, S., Galante, M., Grasso, M., Nardone, A., & Schieppati, M. (1996). Unilateral dis-

placement of lower limb evokes bilateral EMG responses in leg and foot muscles in

standing humans. Experimental Brain Research, 109, 83–91.

Combs, A. W., & Taylor, C. (1952). The effect of the perception of mild degrees of threat on

performance. Journal of Abnormal and Social Psychology, 47, 420–424.

Crossman, D. C., Mueller, B. A., Riedy, C., Dowd, M. D., Villaveces, A., Prodzinski, J., et

al. (2005). Gun storage practices and risk of youth suicide and unintentional firearm

injuries. JAMA, 293(6), 707–713.

D’Agnese, J. (1999). Smart guns don’t kill kids. The technology is here: Why can’t you buy

one? Discover, 20(9), 90–93.

Davis, M. (1984). The mammalian startle response. In R. C. Eaton (Ed.), Neural Mechanisms

of Startle Behavior (pp. 287–351). New York: Plenum.

Delwaide, P. J., & Toulouse, P. (1983). The Jendrassik maneuver: Quantitative analysis of reflex

reinforcement by remote voluntary muscle contraction. In J. E. Desmedt (Ed.), Motor

control mechanisms in health and disease (pp. 661–669). New York: Raven Press.

Dietz, V., Horstmann, G. A., & Berger, W. (1989). Interlimb coordination of leg muscle acti-

vation during perturbations of stance in humans. Journal of Neurophysiology, 62,

680–693.

Dillow, G. (2006). To shoot or not to shoot. Orange County Register, October 22, Local Sec-

tion, p. 1.

Di Maio, V. J. M. (1985). Gunshot wounds. New York: Elsevier.


Driskell, J. E., & Salas, E. (1991). Group decision making under stress. Journal of Applied

Psychology, 76, 473–478.Easterbrook, J. A. (1959). The effect of emotion on cue utilization and the organization of

behavior. Psychological Review, 66, 183–201.Enoka, R. M. (1991). Involuntary muscular contraction and accidental discharge of a fire-

arm. Presented at the Annual Training Conference of the International Association of Law Enforcement Firearms Instructors (IALEFI) meeting in Mesa, Arizona, on September 21, 1991.

Enoka, R. M. (2003). Involuntary muscle contractions and unintentional discharge of a fire-

arm. Law Enforcement Executive FORUM, February 13.

Farah, M. M., Simon, H. K., & Kellerman, A. L. (1999). Firearms in the home, parental per-

ceptions. Pediatrics, 10(5), 1059–1063.

Federal Bureau of Investigation. (2001). The National Uniform Crime Reporting Program:

Law enforcement officers killed and assaulted. Technical report.

Finkenzeller, K. (2003). RFID handbook: Fundamentals and application in contactless smart

cards and identification. West Sussex, UK: John Wiley & Sons Ltd.

Flanagan, T. J. (Ed.). (1997). Sourcebook of criminal justice statistics. Washington, DC: U.S.

Department of Justice, Bureau of Justice Statistics, 1997.

Green, M. Is it a gun? Or is it a wallet? Perceptual factors in police shootings of unarmed

suspects. Available on the Visual Expert Home Page: http://visualexpert.com.

Glete, J. (2000) Warfare at sea, 1500–1650. New York: Routledge.

Glover, S., & Lait, M. (2006). Errant gunshots vex the LAPD. Los Angeles Times, Orange

County Edition, August 17, pp. B1–B5.

Guilmartin, J. F. (2003). Gunpowder and galleys. Annapolis, MD: Naval Institute Press.

Haag, L. C. (2006). Shooting incident reconstruction. Burlington, MA: Academic Press, p. 333.

Hancock, P. A., Hendrick, H. W., Hornick, R., & Paradis, P. (2006). Human factors issues in

firearms design and training. Ergonomics in Design, 14(1), 5–11.

Hawk, L. W., & Cook, E. W. (1997). Affective modulation of tactile startle. Psychophysiol-

ogy, 34, 23–31.

Heim, C., Schmidtbleicher, D., & Niebergall, E. (2006). The risk of involuntary firearms

discharge. Human Factors, 48, 413–421.

Hendrick, H. W. (2000a). Human factors and ergonomics converge a long march. In I. Kuo-

rinka (Ed.), History of the International Ergonomics Association: The first quarter of

a century (pp. 125–142). Geneva: IEA Press.

Hendrick, H. W. (2000b). The technology of ergonomics. Theoretical Issues in Ergonomics

Science 1, 22–33.

Hendrick, H. W., & Kleiner, B. (2001). Macroergonomics: An introduction to work system

design. Santa Monica, CA: Human Factors and Ergonomics Society.

Hendrick, H. W., & Kleiner, B. (Eds.). (2003). Macroergonomics: Theory, methods, applica-

tions. Mahwah, NJ: Lawrence Erlbaum Associates.

Hogg, I. V. (1979). Guns and how they work. New York: Everest House.

Horak, F. B., & Macpherson, J. M. (1996). Postural orientation and equilibrium. In L. B. Row-

ell & J. T. Shepherd. (Eds.), Handbook of physiology, section 12. Exercise: Regulation

and integration of multiple systems (pp. 255–292). New York: Oxford University Press.

Human Factors and Ergonomics Society. (1999). Human Factors and Ergonomics Society

strategic plan, Human Factors and Ergonomics Society directory and yearbook 1999–

2000. Santa Monica, CA: Author.

Human Factors Society. (2006). 2006–2007 directory and yearbook. Santa Monica, CA:

Author.

International Ergonomics Association. (2000). IEA triennial report, 1997–2000. Geneva:

IEA Press.

References 217

Izumi, M. (1996, April). Magna-trigger: The ‘magic ring’ revolver safety. Handguns (pp. 38–40).

Janssen, W., Kulle, K. J., Gehl, A., & Puschel, K. (2001). Der ungewollte Schuss im Polizei-einsatz [Involuntary discharges during police operations]. Archiv fur Kriminologie,

207, 1–11.Jinks, R. G. (1977). History of Smith and Wesson. North Hollywood, CA: Beinfeld Publishing.Kahneman, D. (1975). Effort, recognition, and recall in auditory attention. Attention and

Performance, 6, 65–80.Kauffman, J. A., Bazen, A. M., Gerez, S. H., & Veldhuis, R. N. J. (2003). Proceedings of Pro

RISK 2003, 14th Annual Workshop on Circuits, Systems and Signal Processing, Weld-hoven, The Netherlands. (pp. 379–384). Enschede, NL: University of Twente.

Kearney, R. E., & Chan, C. W. Y. (1981). Interlimb reflexes evoked in human arm muscles by ankle displacement. Electroencephalography and Clinical Neurophysiology, 52, 65–71.

Kelly, J. (2004). Gunpowder. New York: Basic Books.Kerr, B. (1973). Processing demands during mental operations. Memory and Cognition, 1,

401–412.Kolasinski Morgan, E. M. (2005, June). Science of sleep. Law and Order, 106–113.Landis, C., & Hunt, W. A. (1939). The startle pattern. New York: Farrar & Rinehart.Lewinski, B. (2000). Why is the suspect shot in the back? The Police Marksman, 25(6), 20–29.Mayston, M. J., Harrison, L. M., & Stephens, J. A. (1999). A neurophysiological study of mir-

ror movements in adults and children. Annals of Neurology, 45, 583–594.McGrath, J. E. (1976). Stress and behavior in organizations. In M. D. Dunnette (Ed.), Handbook

of industrial and organizational psychology (pp. 1351–1395). Chicago: Rand McNally.McLeod, P. (1977). A dual task response modality effect: Support for multiprocessor models

of attention. Quarterly Journal of Experimental Psychology, 29, 651–667.McPeak, W. J. (2006). Weapons. Military Heritage, 7(6), 12–15.Moore, J. C. (1975). Excitation overflow: An electromyographic investigation. Archives of

Physical Medicine and Rehabilitation, 56, 115–120.Moskowitz, H., & Robinson, C. (1987). Driving-related skills impairment at low blood alco-

hol levels. In P. Noordzij & R. Roszbach (Eds.), Alcohol, drugs, and traffic safety–T86.

Amsterdam: Elsevier.Murphey, R. (1999). Ottoman warfare 1500–1700. New Brunswick, NJ: Rutgers Univer-

sity Press.National Rifle Association (1959). Basics of pistol marksmanship. Washington, DC: Author.National Rifle Association (1989). The basics of personal protection. Fairfax, VA: Author.National Rifle Association (1991). Basics of pistol shooting. Fairfax, VA: Author.National Rifle Association (1995). NRA first steps pistol orientation instructor’s lesson plan.

Fairfax, VA: Author.National Rifle Association (1998). Basics of personal protection. Fairfax, VA: Author.National Rifle Association (2000). Basics personal protection in the home. Fairfax, VA:

Author.National Rifle Association (2001). The basics of personal protection. Fairfax, VA: Author.National Rifle Association. (2004a). Gun safety rules. Fairfax, VA: Author.National Rifle Association. (2004b). Basics of pistol shooting. Fairfax, VA: Author.Neisser, U., & Becklan, R. (1975). Selective looking: Attending to visually significant events.

Cognitive Psychology, 7, 480–494.

Nelson, D. E., Grant-Worley, J. A., Powell, K., Mercy, J., & Holtzman, D. (1996). Popula-

tion estimates of household firearm storage practices and firearm carrying in Oregon.

JAMA, 275(22), 1744–1748.

Newark, T. (2005). Gunpowder armies. Hong Kong: Concord Publications.

Niderost, E. (2006). King Billy at the Boyne. Military Heritage, 7(4), 30–39.


Noteboom, J. T., Barnholt, K. R., & Enoka, R. M. (2001). Activation of arousal response and impairment of performance increase with anxiety and stressor intensity. Journal of

Applied Physiology, 91, 2093–2101.O’Connell, R. L. (2002). Soul of the sword. New York: The Free Press.Paradis, P., and Hendrick, H. W. (2001). Human factors issues in fatal shootings: An analysis of

four cases. In Proceedings of the Human Factors and Ergonomics Society 45th Annual

Meeting (pp. 818–822). Santa Monica, CA: Human Factors and Ergonomics Society.Rachman, S. J. (1983). Fear and courage among military bomb-disposal operators (Special

issue). Advances in Behaviour Research and Therapy, 4(3).Sanders, M. S., & McCormick, E. J. (1993). Human factors in engineering and design (7th

ed.). New York: McGraw-Hill.Schaechter, J., Duran, I., DeMarchena, J., Lemard, G., & Villar, M. (2003). Are “acciden-

tal” gun deaths as rare as they seem? A comparison of medical examiner manner of death coding with an intent-based classification approach. Dept. of Pediatrics, Univ. of

Miami. Report: American Academy of Pediatrics.

Schaubroeck, J., & Ganster, D. C. (1993). Chronic demands and responsivity to challenge.

Journal of Applied Psychology, 78, 73–85.

Selye, H. (1936). A syndrome produced by diverse noxious agents. Nature, 138, 32.

Selye, H. (1976). The stress of life. New York: McGraw-Hill.

Senturia, Y. D., Christoffel, K. K., & Donovan, M. (1996). Gun storage patterns in U.S. homes

with children. Archives of Pediatrics & Adolescent Medicine, 150, 265–269.

Shinohara, M., Keenan, K. G., & Enoka, R. M. (2003). Contralateral activity in homologous

hand muscle during voluntary contractions is greater in old adults. Journal of Applied

Physiology, 94, 966–974.

Smith, K. C. (2001, March). Who needs a smart gun…here’s a smart holster! Handguns,

56–59.

Stanton, N., Hedge, A., Brookhuis, K., Salas, E., & Hendricks, H. (Eds) (2005). Handbook of

human factos and ergonomics methods. Boca Raton, FL: CRC Press.

Staw, R. M., Sandelands, L. E., & Dutton, J. E. (1981). Threat-rigidity effects in organizational

behavior: A multi-level analysis. Administrative Science Quarterly, 26, 501–524.

Stevens, M. M., Gaffney, C. A., Tosteson, T. D., Mott, L A., Olson, A., Ahrens, M. B., et al.

(2001). Children and guns in a well child cohort. Preventative Medicine, 32, 201–206.

Teret, S. P., & Culross, P. L. (2002). Product oriented approaches to reducing youth gun vio-

lence. The Future of Children, 12(2), 119–131.

Tully, E. (1996). Unintentional discharge of police weapons (Part 1). Blue Line Magazine,

8(10), 18–21.

Tully, E. (1997). Unintentional discharge of police weapons (Part 2). Blue Line Magazine,

9(1), 9–11.

Turnbull, S. (2004). The Hussite wars 1419–36. Oxford, UK: Osprey.

Vernick, J. S., O’Brien, M., Hepburn, L. M., Johnson, S. B., Webster, D. W., & Hargarten, S.

W. (2003). Unintentional and undetermined firearm related deaths: A preventable death

analysis for three safety devices. Injury Prevention, 9, 307–311.

Vila, B. (2000). Tired cops: The importance of managing police fatigue. Washington, DC:

Police Executive Research.

Wachtel, P. L. (1968). Anxiety, attention, and coping with threat. Journal of Abnormal Psy-

chology, 73, 137–143.

Weinberg, R. S., & Hunt, V. V. (1976). The interrelationships between anxiety, motor perfor-

mance, and electromyography. Journal of Motor Behavior, 8, 219–224.

Wickens, C. D. (1984). Processing resources in attention. In R. Parasuraman & D. R. Davies

(Eds.), Attention and performance: Volume IV (pp. 63–102). London: Academic Press.

Williams, A. G. (2003). Rapid fire. Shrewsbury, UK: Airlife Publishing, Ltd.

219

Index

A

Acceptance, feelings of, 175Access to handguns, prevention of. see prevention of access to handgunsAction, 48–52AFTE (Association of Firearm Toolmark Examiner), 156Alcohol and unintentional shootings, 22–3, 162American Academy of Pediatrics, 5American National Standards Organization (ANSI), 179Ammunition

cartridge designations, 92–3common features of

cartridge case, 83–6priming systems, 86–7projectile or bullet

caliber, 88–90features, 90subgroups, 90–92

propellant, 87–8conclusion and recommendations, 179history of, 37–40human factors issues related to, 98–9interchangeability/noninterchangeability of, 93–5issues related to, 98–9loading devices, 94NRA safety rules and, 131–2other dangers with, 96–8types of malfunctions, 94, 96

ANSI (American National Standards Organization), 179Anthropometric characteristics, 12, 25–6, 74–5Anxiety, 17Arc of movement, 116Armorers courses, 156–7, 181Assault weapon, 41, 44Association of Firearm Toolmark Examiner (AFTE), 156Automatic handgun, 56, 66–7Axis rod, 56

B

Back strap, 52Ball and post sight pattern, 118Barrel, 48–50Base of projectile, 89–90Base pin, 56Basic Pistol Marksmanship (BPM), 146, 149Basics of Personal Protection (BPP), 146–7, 152Basics of Pistol Shooting (BPS), 110, 146–7, 149, 151–2, 158Battery, semiautomatic in, 68–9


BCPE. see Board of Certification in Professional Ergonomics (BCPE)

Bearing surface, 89–90

Belted cartridge, 83–4

Benchrest position, 113

Berdan priming system, 86–7

Biomechanical positioning, 150

Blanks, 92, 99

Blow forward system, 67

Blowback firearm, 67

Board of Certification in Professional Ergonomics (BCPE), 8, 167, 171, 183

Bolt, 55

Bolt-action handgun, 60

Bottlenecked cartridge, 83–4

Boxer priming system, 87

BPM. see Basic Pistol Marksmanship (BPM)

BPP. see Basics of Personal Protection (BPP)

BPS. see Basics of Pistol Shooting (BPS)

Breath control, 115

Breech force, 53

Bullet. see projectile or bullet

Bureau of Justice Statistics, 4–5

Butt of firearm, 52

C

Caliber designations, 88–90, 98–9

Cannelure cartridge, 85

Cannelure projectile, 89–90

Cap lock firearms, 37–8

Carbines/rifles, history of, 40–42

Carpal tunnel syndrome (CTS), 157

Cartridge designations, 92–3

Cartridges of the World, 89

Cartrige case, 83–6

Causes of unintentional shooting. see also unintentional shooting

alcohol, 22–3, 162

cost of compliance, 25, 73–4, 162

design-induced human error, 26, 162, 178

divided attention, 20–21, 161, 186–7

drugs, 23–5, 162

failure to investigate and report, 155–6

fatigue, 19, 161, 178, 188

involuntary trigger pull, 22, 185

lack of safety training, 29–30

loss of balance, 21

overstressing human capabilities and limitations, 26–9

recall interference, 25

startle, 18–20, 129, 161, 185

stress, 15–18

sympathetic contractions, 21

Center mass sight alignment, 117, 152

Centerfire priming systems, 86–7

Cerebral cortex, function of, 19

Certification, instructor, 159, 182–3

Chamber, 50, 55, 58, 73–4

Children and firearms, 5, 135–6

Chin, 53

Index 221

Classification of shootings, 2–5

Code of Forensic Practice, 170–71

Cognitive ergonomics, 10

Cognitive response to stressful situations, 16

Components and mechanics of handgun

introduction, 47–8

issues related to handgun design, 71–5, 148, 178–9

lock, stock, and barrel, 48

revolver (double action), 53–5

revolver (single action), 56

semiautomatic (self-loading), 56–9

single shot–multiple barrel, 52–3

single shot–single barrel, 49–52

training on, 157–8

Contra lateral irradiation, 21

Core of projectile, 89–90

Cost of compliance, 25–6, 73–4, 162

Counterbalancing firearm weight, 172–4, 194–5

Cowboy Action Shooting, 59

Crane, 54

Crimp of cartridge, 85

Crown, 50

CTD (cumulative trauma disorder), 157

CTS (carpal tunnel syndrome), 157

Cumulative trauma disorder (CTD), 157

Cup and saucer hold, 108–9

Cyclic stress, 18

Cylinder, 55, 72

Cylinder gap, 54

Cylinder release, 55

D

DA (double-action) firearm, 62

DAO (double-action only) firearm, 62

Daubert v. Merrell Dow Pharmaceuticals Inc., 169

Dead weight (DW) system, 119–20

Deafness and ear protection, 132–4

Death-gripping, 108

Deaths, gun-related, 5

Decocker, 58

Deflagration of gunpowder, 88

Design-induced human error, 26, 162, 178

Disabilities, physical, 157, 182

Discriminability issues with ammunition, 99

Distorted perception, 17

Divided attention, 20–21, 161, 186–7

Double-action (DA) firearm, 62

Double-action only (DAO) firearm, 62

Drugs and unintentional shootings, 23–5, 162

Dum-dum, 92

Dummy cartridges, 97–9

DW (dead weight) system, 119–20


E

Ear protection, 132–4Ejection port, 57Ejector, 50, 55, 58Ejector housing, 56Ejector rod, 55–6Elation, feelings of, 175Emotional reactions to stress, 17, 174–5Environmental stress, 18Ergonomic design or engineering, 8Ergonomics. see human factors/ergonomics (HF/E)Ergonomics In Design (EID), 10, 163Ergonomics Society, 163Expanding (semijacket) projectile, 91–2Extensor muscles, 106Extractor, 50, 55, 58Extractor groove, 84–5Extractor rod, 55Eye protection, 132–4

F

Fatigue, 19, 161, 178, 188Fear, 17, 20FG (force gauge) system, 119Fight-or-flight physiological alert response, 15Fingerprint recognition, 140Firearms. see also handgun

characteristics and human factors implications, 11children and, 5, 135–6history of

ammunition, 37–40cap lock, 37–8flint lock, 36–7gunpowder and early guns, 31–4matchlock, 34–5pocket pistols, 44revolvers, 42–3rifles/carbines, 40–42semiautomatics, 43–4wheel lock, 35–6

Firing pin, 51, 58Fixed sights, 117Flash hole, 85Flexor muscles, 106Flint lock firearms, 36–7

Flutes, 55

FMJ (full metal jacket) projectiles, 91

Follow-through, 121–4

Force gauge (FG) system, 119

Forcing cone, 54

Forensics

finding HF/E experts, 171

HF/E professionals as expert witnesses and consultants in litigation, 162–8

human factors code of forensic practice, 170–71

human factors issues in litigation involving firearms incidents, 161–2

Index 223

other human factors issues to consider, 172–5other relevant forensics sciences, 175use of HF/E experts, 168–70

Forensics Professional Group (FPG), 162–71Frame, 48Front strap, 52Frustration, 17Full metal jacket (FMJ) projectiles, 91Fundamentals of shooting a handgun

basic essential components, 149breath control, 115case studies, 188–9follow-through, 121–4grip

death-gripping, 108eye dominance and proper grip hand, 106–7proper fit of hand and firearm, 107–8

use of support hand, 108–10

overview, 105–6, 188–9

sight alignment and sight picture, 115–18

stance

benchrest position, 113

isosceles position, 111

one-handed standing position, 114–15

overview, 109–11

strong isosceles position, 112–13

Weaver stance, 113–14

trigger control, 118–21

G

Gas-operated semiautomatic, 61, 67

Glaser Safety Slug, 92

Grip (handle of firearm), 52, 74–5

Grip (holding the firearm)

death-gripping, 108

eye dominance and proper grip hand, 106–7

proper fit of hand and firearm, 107–8

use of support hand, 108–10

Grip cocking access system, 138–9

Grip-pattern recognition, 140

Grooves and lands, 50

GSR (gun shot residue), 189

Guide to the Basics of Personal Protection Outside the Home (PPOH), 146

Gun control efforts, 1

Gun shot residue (GSR), 189

Gun vaults, 137–8

Gunpowder, 31–4, 87–8, see also propellant

H

Hair trigger, 118

Half-cocked hammer, 65, 73

Hammer, 50–51

Hammer block system, 64

Hammerless, 51, 139


Hand, 55Hand cannon, 31–4Handgun. see also firearms

actions, 61–2

awareness of accidental firing, 1

components of (see components and mechanics of handgun)

defined, 47

fundamentals (see fundamentals of shooting a handgun)

history of (see history of firearms)

prevention of access to (see prevention of access to handguns)

revolver (see revolver)

semiautomatic (see semiautomatic firearm)

training (see training)

unsecured, 135–6

variations of, 59–62

Hang fire, 94

Head of cartridge, 85

Headstamp labeling, 85–6, 98

Hearing and ear protection, 132–4

Heel of projectile, 89–90

HF/E. see human factors/ergonomics (HF/E)

HFES (Human Factors and Ergonomics Society), 10, 162–71

HFES Consultants Directory, 183

HIST (human-system interface technology), 9–10

History of firearms

ammunition, 37–40

cap lock, 37–8

flint lock, 36–7

gunpowder and early guns, 31–4

matchlock, 34–5

pocket pistols, 44

revolvers, 42–3

rifles/carbines, 40–42

semiautomatics, 43–4

wheel lock, 35–6

Hollow point projectile, 91

Home protection handguns, preventing access to. see prevention of access to handguns

Human capabilities and limitations

anthropometrics, 12, 26–7, 74–5

conclusion and recommendations, 178

instructor training for, 157, 182

negative transfer of training, 28–9, 71–3

perception, 27

response time, 28

workload, 27–8

Human characteristics, 11–12

Human Factors and Ergonomics Society (HFES), 10, 162–71

Human Factors Directory and Yearbook, 171, 183

Human factors/ergonomics (HF/E)

academic degree programs, 164

access to handgun, 136

ammunition and, 85–6, 88, 91–4, 96–9

causes of shootings (see causes of unintentional shootings)

conclusions and recommendations, 177–83

definition of, 8, 10

design guidelines and standards, 164

forensics and (see forensics)

Index 225

fundamentals and, 105–11, 113, 115, 118–20, 122–3government sponsored research, 164handgun design and, 47, 52, 71–5, 148, 178–9historical beginning of, 8–9human characteristics, 11–12human-system interface technology (HIST), 9–10industrial research, 165need for, 177–8safety concerns (see safety concerns)specialists and experts, 162–71, 177–8, 183training, 147–8

Human-environment interface technology, 9Human-job interface technology, 10Human-machine interface technology, 8–10Human-software interface technology, 10Human-system interface technology (HIST), 9–10Hunter safety course, 146

I

Inadvertent shooting, 2, 5–8, 185–92Incentives for safety training, 160, 181Inertia and trigger pull, 172–3, 193–5Instructional system development (ISD), 158, 181–2Instructor issues, 157–9, 181–3Intent, determining, 172–4, 193–5Intentional shooting, 2, 7–8International Ergonomics Association, 8, 163Involuntary shooting, 2Involuntary trigger pull, 22, 185ISD (instructional system development), 158, 181–2Isosceles position, 111

J

Jacket of projectile, 89–90

K

Key-locking access systems, 140Keypad entry access system, 139–40Kick (recoil), 66, 108, 121

L

Lands and grooves, 50Lawsuits against gun manufacturers, 1Lead projectile, 90–91Licensing for handgun operators, 159–60Loading devices, 94Loading gate, 56Lock, 48, 55Lock boxes, 137–8Lock notches, 55


Locked breech system, 67–8Loss of balance, 21

M

Macroergonomics, 10Magazine, 58, 72Magazine release, 58Magazine well, 59Magnetic access system, 138Magnetic/electric access system, 138Main spring, 55Man-machine interface technology. see human-machine interface technologyMatchlock firearms, 34–5

Material of cartridge case, 85

Mechanics of handgun. see components and mechanics of handgun

Meplat, 89–90

Mirror movement, 21

Misfire, 94, 99

Modified isosceles position, 112–13

Moon clip, 94–5

Mouth of cartridge, 84–5

Movement, arc of, 116

Muscle neutral position, 106

Muzzle, 49–50

N

Narrowed attention, 16

National Center for Vital Statistics, 5

National Rifle Association (NRA), 128–34, 146–54

Neck of cartridge, 84–5

Negative transfer of training, 28–9, 71–3

Night sights, 118

Novelty projectiles, 92

NRA. see National Rifle Association (NRA)

O

Ogive, 89–90

One-handed standing position, 114–15

Oxford Research Institute (ORI), 167

P

Pawl, 55

PDW (Personal Defense Weapon), 42

Pediatric deaths, general rate of, 5

Perception, 27

Performance rigidity, 16

Permit, concealed weapon, 1, 145

Personal Defense Weapon (PDW), 42

Personal Protection in the Home (PPIH), 146–7, 149–50, 152–3

Personal Protection Outside the Home (PPOH), 146–7, 153

Index 227

Physiological characteristics, 11, 15–16, 19Pistol, 47, see also handgunPocket pistol, history of, 44Point shooting, 98Police, shootings involving, 6, 140, 186–7Poor judgment, 16PPIH. see Personal Protection in the Home (PPIH)PPOH. see Personal Protection Outside the Home (PPOH)Prawl, 53Pressure plates, 53Prevention of access to handguns

conclusion and recommendations, 180external restraints, 137–8, 186personalized access systems, 138–41problem with, 135–6, 186

Primer pocket, 84–5Priming, 17, 191Priming systems, 86–7Projectile or bullet

caliber, 88–90features, 90subgroups, 90–92

Propellant, 87–8, 99, see also gunpowderPush/pull hold, 108–10

Q

Quick loaders, 94

R

Radio frequency identification (RFID), 140

Ratchet, 55

Rebated cartridge, 83–4

Recall interference, 25, 187

Recoil (kick), 66, 108, 121

Refresher training, 151, 156–7, 181

Release, 57

Reloading ammunition, 96, 132

Remorse, feelings of, 175

Repetitive stress injury (RSI), 157

Reporting unintentional discharge, lack of, 155–6

Residual stress, 18

Response time, 28

Reticular Activating System (RAS), 19

Revolver

actions, 61–2

components of, 53–6

defined, 47

double action (DA), 62

double action only (DAO), 62

history of, 42–3

operation, loading, unloading, safety, 62–6

single action (SA), 61–2

tip up, 59

top break, 59–60


trigger control of, 119RFID (radio frequency identification), 140

Rifles/carbines, history of, 40–42

Rimfire priming system, 86–7

Rimless cartridge, 83–4

Rimmed cartridge, 83–4

Round nose projectile, 90–91

RSI (repetitive stress injury), 157

S

SA (single-action) firearm, 61–2

Saf-T-Lock system, 139–40

Safety (component of firearm)

defined, 51–2

negative transfer of learning, 71, 73

revolver, 64


Safety concerns

ammunition, 85–6, 88, 91–4, 96–9

fundamentals, 105–11, 113, 115, 118–20, 122–3

handgun design, 47, 52, 71–5, 148, 178–9

prevention of access to handgun, 136

revolvers, 63–6

safety rules, 128, 130, 133


training, 147–8

Safety Hammerless, 139

Safety rules

complete versus abbreviated rules, 130

conclusion and recommendations, 180

conflicting rules, 127–8

failure to follow, 185–92

NRA rules

of safe firearm handling, 129–30

of safe firearm use and storage, 130–34

Sales of guns, 1

Self-doubt, feelings of, 175

Self-induced lifestyle stress, 18

Semiautomatic firearm

components of, 56–9, 66

defined, 47, 66

double action (DA), 62

double action only (DAO), 62

gas-operated, 61, 67

history of, 43–4

method of operation, 67–8

placing in battery, 68–9

safeties, 70–71

single action (SA), 61–2

unloading, 69–70

Semijacket (expanding) projectile, 91–2

Semirimmed cartridge, 83–4

Semiwadcutter projectile, 90–91

SG (spring gauge) system, 119

Shoulder of bullet, 89–90

Shoulder of cartridge, 84–5

Index 229

Sight (component of firearm), 50, 115–18

Simulators, 154–5

Single shot–multiple barrel handgun, 52–3

Single shot–single barrel handgun, 49–50

Single-action (SA) firearm, 61–2

Six o’clock hold, 116, 152

Slide, 57

Slide lock, 57

Smart card, 140–41

Smart guns, 140

Smokeless powder, 87–8

Societal concern for street shootings, 1

Soft point projectile, 91

Solenoid use limitation device, 138

Speed loaders, 94

Spring gauge (SG) system, 119

Squib load, 96

Stance

benchrest position, 113

inappropriate, 150

isosceles position, 111

one-handed standing position, 114–15

overview, 109–11

strong isosceles position, 112–13


Standardization, lack of

ammunition labeling, 98–9, 179

handgun design, 71–3, 179

safety training courses, 151, 182

Startle, 18–20, 129, 161, 185

Stock, 48

Straight cartridge, 83–4

Stress

chronic, 18

cognitive responses to, 16

conclusion and recommendations, 177–8

emotional reactions, 17

failure to teach effects and nature of, 149

forensics issues and, 161, 174–5, 188

physiological nature of, 15–16

Strong hand, 106

Strong isosceles position, 112–13

Suicide, 3, 7

Support hand, 107–9

Sympathetic contractions, 21

Sympathetic discharge, 186–7

T

Tang, 58

Tapered cartridge, 83–4

Target, 150–51

Target analysis guide, 124

Testing for handgun operators, 159–60

Three dot sight pattern, 118

TMJ (total metal jacket), 91

Top strap, 53


Total metal jacket (TMJ), 91Training

adequate training versus true adequacy, 145–6conclusion and recommendations, 180–83current handgun training programs

comments regarding NRA courses, 151–4content issues, 147–51major programs, 146–7

failure to investigate and publish reports, 155–6instructor issues, 157–9, 181–2lack of, 29–30, 186, 188strategies for encouraging, 159–60why training is essential, 143–5with advanced technology, 154–5

Training, safety, 29–30Transfer bar system, 64Trigger

anthropometric considerations, 75control, 118–21defined, 51

effects on trigger pull and intent, 172–4, 193–5

issues to consider in forensics, 172–4

negative transfer of learning, 72–3

Trigger guard, 52, 74

Trigger locks, 137–8

U

U.S. Department of Justice, Bureau of Justice Statistics, 4–5

Unintentional shooting, 2, 5–8, 185–92, see also causes of unintentional shooting

University of Miami School of Medicine, 5

Unsecured handguns, 135–6

V

Voice recognition, 141

W

Wadcutter projectile, 90

Weak hand, 107


Web of cartridge, 85

Weight of trigger pull, 119–20, 172–4, 193–5

Wheel lock firearms, 35–6

Window, 55

Workload, 27–8

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