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FBI Handgun Wounding Factors and Effectiveness
U.S. Department of Justice

Handgun Wounding Factors and Effectiveness

Special Agent UREY W. PATRICK

FIREARMS TRAINING UNIT
FBI ACADEMY
QUANTICO, VIRGINIA

July 14, 1989

Forward

The selection of effective handgun ammunition for law
enforcement is a critical and complex issue. It is
critical because of that which is at stake when an
officer is required to use his handgun to protect his
own life or that of another. It is complex because of
the target, a human being, is amazingly endurable and
capable of sustaining phenomenal punishment while
persisting in a determined course of action. The issue
is made even more complex by the dearth of credible
research and the wealth of uninformed opinion regarding
what is commonly referred to as "stopping power".

In reality, few people have conducted relevant research
in this area, and fewer still have produced credible
information that is useful for law enforcement agencies
in making informed decisions.

This article brings together what is believed to be the
most credible information regarding wound ballistics. It
cuts through the haze and confusion, and provides
common-sense, scientifically supportable, principles by
which the effectiveness of law enforcement ammunition
may be measured. It is written clearly and concisely.
The content is credible and practical. The information
contained in this article is not offered as the final
word on wound ballistics. It is, however, an important
contribution to what should be an ongoing discussion of
this most important of issues.

John C. Hall
Unit Chief
Firearms Training Unit

Conclusions

Physiologically, no caliber or bullet is certain to
incapacitate any individual unless the brain is hit.
Psychologically, some individuals can be incapacitated
by minor or small caliber wounds. Those individuals who
are stimulated by fear, adrenaline, drugs, alcohol,
and/or sheer will and survival determination may not be
incapacitated even if mortally wounded.

The will to survive and to fight despite horrific damage
to the body is commonplace on the battlefield, and on
the street. Barring a hit to the brain, the only way to
force incapacitation is to cause sufficient blood loss
that the subject can no longer function, and that takes
time. Even if the heart is instantly destroyed, there is
sufficient oxygen in the brain to support full and
complete voluntary action for 10-15 seconds.

Kinetic energy does not wound. Temporary cavity does not
wound. The much discussed "shock" of bullet impact is a
fable and "knock down" power is a myth. The critical
element is penetration. The bullet must pass through the
large, blood bearing organs and be of sufficient
diameter to promote rapid bleeding. Penetration less
than 12 inches is too little, and, in the words of two
of the participants in the 1987 Wound Ballistics
Workshop, "too little penetration will get you killed."
42,43 Given desirable and reliable penetration, the only
way to increase bullet effectiveness is to increase the
severity of the wound by increasing the size of hole
made by the bullet. Any bullet which will not penetrate
through vital organs from less than optimal angles is
not acceptable. Of those that will penetrate, the edge
is always with the bigger bullet.