Handgun Stopping Power

( http://mcp.cpu.lu/handguns/database/reports/StoppingPower/Power.htm )

Guns, Handguns can be great collection items. They have their place in history and will
ever be part of it. They provide fun in shooting contests from plinking to serious
competition.

They are companion to policemen, agents, hunters and some civilians. But, handguns
and ammunition are made to KILL, we have to keep that always in mind ! This is
certainly a reason why guns are intriguing and interesting to most people or just the
opposite for others. As long as men have made weapons, they've searched for means of
accurately gauging their effectiveness. All sorts of targets, animate and inanimate, have
been pressed into service to test the efficacy of small arms projectiles. Today, we have a
plentitude of handguns and ammunition to chose from, and that task is perhaps another
story.

But generally speaking, how effective are common handgun rounds when fired at human
targets. Now, let's look at the efforts of some people to give us an insight and
understanding in this use of force. Here presented briefely are some interesting
works that have been undertaken to evaluate and predict handgun stopping
power.

Some known studies on this subject

The Thompson & LaGarde tests,Ordonance Dept. US Army, 1903; shooting cattles and dead bodies

The RII (relative incapacitation index), National Institute of Justice, 1972; hit probability & computer simulation tests

The FBI tests, Quantico Academy, 1980; different media shooting tests and evaluations

The FBI study, Quantico Academy, 1987, expert boards gathers and conclude on ammo effectiveness

The Police Marksman/Fairburn tests, 1989; gathering factual data on stopping power with documented shootings
The Navy/Crane 9mm ammo tests, Naval Weapons Support Center, 1991; various performance in test mediums

The Strasbourg tests, 1991; shooting living goats and measuring ammo performance (here presented)

The Royal Canadian Police tests, Canadian Police Research Center, 1994; gelatin performance, various scenarios

Study 1 : The Strasbourg Test

In 1991, a privately funded research group was formed to study the physiological effects
of bullet impact on medium sized animals. The animals selected for testing were male
French Alpine goats of circa 160 pounds. A needle transducer was surgically implanted in
the carotid artery of each goat. After that precedure each goat was allowed several days
to recover. A goat was then placed in a stall and needle electrodes were inserted and
fixed into its scalp and hooked to an oscilloscope to monitor the goats behavior. If the
goat was observed to be stable, it was confined to a cubicle, hooked up to recording
equipment and allow to eat from a shaped container that forced the goat to be in a
position aligned with the shooters line of fire.

If all conditions were favorable to the testers, the goat was then shot into the side aiming
the lung area at a distance of 10 feet. Cameras, equipment and the testers recorded the
animal's reactions. If the goat wasn't dead after 60 seconds, it was terminated humanely
by marksmen. Data from autopsy, recording equipments and cameras afforded a basis
to calculate an Incapacitation Index fir each bullet as well as to compare all the statistical
and medical data to determine the real causes of bullet performance. The data measured
would also give conclusions on the physiological reactions (blood pressure, brain activity,
etc..) to the shot. 611 goats were shot. The tests and evaluations lasted for 18 months.

The calibers involved were: .38spl, .357mag, .380auto, 9mm, 10mm, .40auto and
.45auto. The guns (3 revolvers and 5 pistols) ranged from 3-5 inches in barrel lenght.
Conventional ammo and frangible ammo like Glaser and MagSafe were used. Although
the frangible ammo was concluded to be ideal in this scenario ( shot to the lung ), i just
listed the AIT of some of the conventional ammo used in these tests. Frangible ammo
had AIT's of around 4-5 seconds with the calibres over .380 auto. In some cases, the
goat was instantly incapacitated due to a increase in blood pressure. This increase and
subsequent pulsing of the pressure was attributed to the high velocity frangible ammo. In
some cases, with the .38 spl FMJ bullets, the goat seems to notice something inhabitual
but wasn't incapacitated and had to be terminated.

Here listed for our purpose, is the AIT (Average incapacitation Time) expressed in
seconds. A goat was incapacitated if it collapsed and was unable to stand up. The final
results are close to those obtained by Marshall and Sanow in their study

Study 2 : Deadly Effects

The video "DEADLY EFFECTS", produced by Alexander Jason, former military and police
officer. With the participation of Col. Martin Fackler, combat wound surgeon and director
of the U.S.Army Wound Ballistic Laboratory as well as other noted experts. Col. Fackler
observes that about 40% of those shot will immediately fall down without a predictable
phenomen.

He makes, among other observations, the suggestion that years of exposure to
TV/Movies may have created a "hypnotic suggestion" to fall to a shot and that this sort of
psychogenic effect may explain some otherwise inexplicable reactions to a shot. Jason,
reviewing the theory behind the temporary wound cavity created by the bullet
(explained later here in this report) displacing tissue as it speeds through it, believes
that it is misplaced, since many types of elastic tissue are simply pushed aside by the
temporary cavity rather than being destroyed. Col. Fackler on velocity; it cannot be
separated out from other wound variables as it is not necessary to get a big temporary
wound cavity. Also the kinetic energy as well as the pain are not an important factor in
bullet effectiveness, according to Jason. Often, there are reported lacks of pain at the
instant of the gunshot wound.

On Stopping Power: Jason states that the only thing that matters is what organ, tissue,
or vessel is actually hit and destroyed by the bullet. Without recommendation, the larger
a bullet, the better chance it has to hitting and injuring something inside the body. While
expanding bullets help in this, they don't always work as intended in real life shootings.
Based on Col. Facklers work, he recommends a minimum penetration capability of 35cm
(14inch) to insure reaching vital organs under most normal cicumstances.

The most important factor in incapacitation is hitting a critical area of the body. To do
this, one needs a reliable, accurate handgun and a high degree of shooting skill.

Incapacitation is enhanced by a large permanent cavity, big bullet diameter and reliable
expanding bullet, deep reliable penetration (heavy bullet) and multiple hits.

Study 3 : Handgun Stoppping Power

The words Stopping Power refers to the work of Marshall & Sanow that is presented
here. The term has to be seen as an index to express the overall effectiveness of a
handgun and is not to be attributed to some magic force in conjuction with handguns.

While many theories have been issued on predicting handgun effectivenes, very few are
those including real life people shootings to predict it. That was the idea behind the men
that raised interest and controverse in the US wound ballistic scene. The work of Marshall
and Sanow.

Some experts criticize this work, claiming that the statistical data of over 6000 reported
shootings is incorrectly presented due to the fact that the victim's physiological and
psychological state, as well as the exact tissue hit by the bullet were not integrated in
this study, and therefor a conclusion on bullet effectivenes can only be wrong. They
admit, however, that other conclusions and theories of this works (resulting partly from
the same data !) are true and justified.

My views about it (i personally work on statistics of other nature): Including a lot of
precise info in a statistic can better the results, but one should try to compile the data
reasonably, compromisingly, to come up with a more realistic degree of results. I mean,
if you would consider all the variations there are in a shooting, you would almost come
up with 6000 differences for 6000 shootings. So, we have to accept some compromising
degree of innaccuracy and will come up with a viable result. For example, if you will be
forced to shoot, 1) will you know the exact state of the opponent, 2) will you know
exactly what all of your bullets gonna hit very precisely always: The answer is NO ! So
you have to eliminate this, and bring it down to more realistic statistics that finally will
not be 100%, but certainly will be very accurate in predicting the outcome. The data
collected by Marshall & Sanow is perhaps the most usefull information that can
be counted on !

How Stopping Power is determined (Marshall & Sanow)

The bullet must strike the torso (excluding the head and neck) of a person. It seems
obvious that a bullet that strikes a hand, leg, arm or foot, will almost certainly never
bring about instantaneous incapacitation. Secondly, a successful one-shot stop occurring
in the neck or head owes its success to shot placement, rather than calibre or bullet
design.
Multiple hits have to be discarded. We are interested in the effect of a single bullet. Again
it is obvious that multiple shots will be more effective, however it is impossible to
determine some measure of bullet performance based on multiple shots.

Figures are provided only when a minimum of five instances of shooting with a particular
load/calibre combination have occurred. In addition, some of the following information
must have been available: police reports, evidence technician reports, homicide reports,
autopsy results, and photos (among other things). In addition, the actual recovered
bullets or photographs of the bullets must have been available for examination.

The test medium gelatin and predictions (Marshall & Sanow)

First used around 1921, ordnance gelatin is a powdered animal protein substance made
from the bones, skin or other tissue of livestock and especially formulated for ballistic
research. The powder is mixed by weight with water, normally 10%. Allowed to gel, the
mixture forms a though, rubbery transparent substance that closely mimics the density
and elastic properties of tissue. It is possibly to predict stopping power by testing bullets
in ordnance gelatin. The first key to correct conclusions is tu use all of the information the
gelatin gives. The second key is to analyze the gelatin results in a way that correlates
with actual street results. When analyzing the effects of a bullet passing through the
gelatin, a number of measurements must be taken to get the full wounding prediction.
These include the permanent crush cavity, the temporary stretch cavity, the actuel
depht of bullet penetration, and the number and depth of bullet fragments that leave the
main bullet path, if any. While it remains heavily debated, we believe that the most
significant (though not exclusive) measurement is the permanent crush cavity. This is the
amount of tissue actually touched, crushed, or pulped by the bullet itself, and is the
dominant wound predictor at most handgun velocities. The exceptions are the hig-
velocity magnum loads in the 1400+ fps range. Other exceptions are contact-type
wounds where the powder continues to burn and create pressure inside the wound. The
crush cavity is the dominant wound predictor because of its reliability. The effects of the
crush cavity on tissue are predictable and repeatable from shot to shot from tissue to
tissue. Simply put, if the bullet runs into a blood vessel, it will tear it or cut it in half. If
the bullet meets a lung or the liver, it will put a hole in them, this is real and instant
damage.

The proven reasons why people fall: Loss of oxygen from loss of blood and loss
of motor control from damage to the nervous system. The most predictable
way to damage something is to crush it, not to stretch it. Of profound but
secondary importance is the temporary stretch cavity, the tissue violently shoved out of
the way by the passing bullet. Due to inertia, the tissue stretches radially outward away
from the bullet path, forming an air cavity in the wake of the bullet. The tissue reaches a
point of maximum stretch, then collapses back to its original position. The rebounding
tissue bounces off itself outward and back again in an ever decreasing amplitude until it
comes to rest. The entire stretch-and-collapse cycle takes place in well under half a
second in most tissue. However, some tissue is stretched and actually torn open by the
maximum stretch cavity, depending on its size. The liver, spleen, and kidneys are
specially sensitive to stretch. Their relative density and lack of elesticity can result in
damage far greater then the diameter of the passing bullet, especially for the liver. In
addition to the permanent damage, the temporary stretch cavity can also generate a
stress signal strong enough to overload the victim's consciousness, wich is controlled by
the reticular activating system located in the brain stem. The result is unconsciousness in
1 to 2 seconds. For all the damage and effects the temporary stretch cavity can have,
the problem is that absolutely nothing can also be the result. Signals to the brain can be
blocked by drugs, alcohol, and a strong mindset. Mostly all organs, aside the liver, can
take the blunt trauma produced by normal handgun velocities.

The permanent crush cavity is the tissue crushed by the bullet, it's diameter and depth.
The temporary stretch cavity, seen here darkened on the picture lasts only half a second
in real tissue.

Bullet effectiveness (Marshall & Sanow)

Disrupting or severely impairing the supply of oxygen carrying blood to the brain.
A bullets most likely effect on a human being is to somehow damage the vascular
system. Bullets cause vascular damage by either severing or tearing blood vessels. This
damage is caused by either the bullet itself, and/or by fragments of the bullet or bone
fragments and foreign bodies brought into the body with the bullet. In rare cases, very
high energy bullets (from rifles, contact shotgun wounds, and sometimes magnum
calibre handguns) can cause sufficient hydrostatic shock to actually stretch tissue,
resulting in ruptured vessels. The problem with relying on this mechanism is that it is
extremely slow to have an effect. Even if a bullet completely demolishes a persons
heart, that person can remain functional for up to twelve seconds, and it is extremely
unlikely that a bullet will have such an extreme effect. Usually blood loss is a very
gradual process.

Disruption of the central nervous system.

By far the most effective shot placement is the head area, specifically within the cranial
vault or the brain-stem itself. (Any bullet destroying the brain-stem will guarantee an
instantaneous collapse). There are two main problems with this mechanism. Firstly, the
head is the smallest and most rapidly moving area of the target, and hence the most
difficult part to hit. Secondly, its not called the cranial *vault* for nothing! The bones of
the skull are extremely tough, and there are many, many cases where people have been
shot in the head, and the bullet has glanced off doing only superficial damage. However,
once the bullet is inside the cranial vault, it causes damage by physically crushing areas
of the brain, and by causing damage via hydrostatic shock (far more damaging in the
cranial vault than in the vascular system). Almost all rifle, close-range shotgun and high-
power handguns will result in an instantaneous collapse with a shot to the head.

Breakage of bones and the skeletal support structure.

This is the most likely mechanism to cause instant collapse, but the most unlikely to
result in a successful "stop". Almost all reasonable calibre bullets are capable of breaking
bones. However, even if the hip bone is completely destroyed and the person has no
choice but to fall to the ground, he will still be perfectly capable of returning fire! As a
general rule, shots designed specifically to break bones cannot be relied on to bring
about a stop to hostilities.

Psychological reasons.

Over many years, people, through the media, have become accustomed to seeing other
people react in a certain way when shot. Such situations are so common that many
people have actually become brain-washed into reacting in a certain way when shot, and
if TV is anything to go by, that involves dropping helplessly to the ground, instantly. As
hard as this is to believe, a case occurred when an officer in an Illinois fast-food
restaurant was confronted by a robber armed with a .22 rifle. The robber fired, and the
officer felt a sharp, hot, stinging sensation in his stomach. As he fell to the ground in
pain, he was able to shoot the robber. However, once the action was over, the officer
found that he had not been hit at all, and yet his very real, but imagined pain had
actually forced him to the ground, were he not to have shot the robber, he would have
most likely have been killed!

Neural Shock.

Human consciousness is controlled largely by an area at the lower part of the brain-stem
called the reticular activating system, which can be disrupted by physical damage,
pressure emanating from the cranial vault, or by intense emotion or physical pain. One
theory has it that organs like the liver, spleen, kidneys and especially the stomach can
send pain impulses to the brain-stem indicating a severe or overwhelming body injury, in
which case the reticular activating system produces a functional "shutting down" of this
system, and a resulting loss of consciousness within one or two seconds. Drugs such as
PCP and heroin and to a lesser extent alcohol are known to impair this function,
sometimes resulting in cases where people seem immune to gunshots, even from
multiple rifle and shotgun wounds.

Street results data (Marshall & Sanow)

R/S = total Recorded shootings and one-shot Stops, SP% = Stopping Power expressed in %

Special thanks to Evan MARSHALL (he gently allows me to present some data from his work) and to Ed SANOW.

Thanks to: Combat Handguns Magazine, Dale Towert, and the makers of Deadly Effects.

(c)2000