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Synopsis Of The FBI Ammunition
Test Protocol
"Synopsis Of The FBI Ammunition Test Protocol." I did not author this information. Credit should be given to the FBI as it is from the "Annual" Report of results of handgun ammunition testing.
So there you have it, the FBI has been duly credited!
| After extensive research and consultation, the FBI established that
a handgun bullet must consistently penetrate a minimum of 12 inches of
tissue in order to reliably penetrate vital organs within the human target
regardless of the angle of impact or intervening obstacles such as arms,
clothing, glass, etc. Penetration of 18 inches is even better. Given
minimum penetration, the only means of increasing wound effectiveness is
to enlarge the permanent cavity. This increases the amount of vital
tissues with a marginally placed shot, and increases the potential for
quicker blood loss. This is important because, with the single exception
of damaging the central nervous system, the ONLY way to force incapacitation
upon an unwilling adversary is to cause enough blood
loss to starve the brain of its oxygen and/or drop blood pressure to zero.
This takes time, and the faster haemorrhage can occur the better.
The FBI ammunition test protocol is a series of practically oriented tests to measure a bullet's ability to meet these performance standards. The result is an assessment of a bullet's ability to inflict effective wounds after defeating various intervening obstacles commonly present in law enforcement shootings. The overall results of a test are thus indicative of that specific cartridge's suitability for the wide range of conditions in which law enforcement officers engage in shootings. The test media used by the FBI to simulate living tissue is 10% ballistic gelatin (Kind & Knox 250-A), mixed by weight. The gelatin is stored at 4x Centigrade (39.2x Fahrenheit) and shot within 20 minutes of being removed from the refrigerator. The temperature of the gelatin is critical, because penetration changes significantly with temperature. This specific gelatin mix was determined and calibrated by the U.S. Army Wound Ballistics Research Laboratory, Presidio of San Francisco, to produce the same penetration results as that obtained in actual living tissue. Each gelatin block is calibrated before use to ensure its composition is within defined parameters. The gelatin blocks for handgun rounds are approximately six inches square and 16 inches long. As necessary, additional blocks are lined up in contact with each other to ensure containment of the bullet's penetration. Each shot's penetration is measured to the nearest 0.25 inch. The projectile is recovered, weighed and measured for expansion by averaging its greatest diameter with its smallest diameter. The ammunition test protocol using this gelatin is composed of eight test events. In each test event, five shots are fired. A new gelatin block and new test materials are used for each individual shot. The complete test consists of firing 40 shots. Each test event is discussed below in order. All firing in these eight test events is done
with a typical service weapon representative of those used by law enforcement.
The weapon used is fully described in each test report.
Test Event l--Bare Gelatin The gelatin block is bare and shot at a range
of ten feet measured from the muzzle to the front of the block. This
test event correlates FBI results with those being obtained by other researchers,
few of whom shoot into anything other than bare gelatin. It is common
to obtain the greatest bullet expansion in this test. Rounds which
do not meet the standards against bare
Test Event 2--Heavy Clothing The gelatin block is covered with four layers
of clothing: One layer of cotton T-Shirt material (48 threads per
inch); one layer of cotton shirt material (80 threads per inch);
a I0 ounce down comforter in cambric shell cover (232 threads per inch);
and one layer of 13 ounce cotton denim (50 threads per inch). This
simulates typical cold weather wear. The block is shot
at ten feet, measured from the muzzle to the front of the block.
Test Event 3—Steel Two pieces of 20 gauge, hot rolled steel with
a galvanised finish are set three inches apart. The steel is in six
inch squares. The gelatin block is covered with light clothing and
placed 18 inches behind the rear most piece of steel. The shot is
made at a distance of I0 feet measured from the muzzle to the front of
the first piece of steel. Light clothing is one layer of cotton
T-Shirt material and one layer of cotton shirt material, and is used in
all subsequent test events. The steel is the heaviest gauge steel
commonly found in automobile doors. This test simulates the weakest
part of a car door. In all car doors, there is an area, or areas,
where the heaviest obstacle is nothing more than two pieces of 20 gauge
steel.
Test Event 4—Wallboard Two pieces of half-inch standard gypsum board
are set 3.5 inches apart. The pieces are six inches square.
The gelatin block is covered with light clothing and set 18 inches behind
the rear most piece of gypsum. The shot is made ten feet, measured
from the muzzle to the front surface of the first piece of gypsum.
This test event simulates a typical interior building wall.
Test Event 5—Plywood One piece of three-quarter inch AA fir plywood
is used. The piece is six inches square. The gelatin block
is covered with light clothing and set 18 inches behind the rear surface
of the plywood. The shot is made at ten feet, measured from the muzzle
to the front surface of the plywood.
This test event simulates the resistance of typical wooden doors or construction
timbers.
Test Event 6--Automobile Glass One piece of A. S. I. one-quarter inch laminated
automobile safety glass measuring l5 x l8 inches is set at an angle of
45 degrees to the horizontal. The line of bore of the weapon is offset
15 degrees to the side, resulting in a compound angle of impact for the
bullet upon the glass. The gelatin block is covered with light clothing
and set 18 inches behind the glass. The
Test Event 7--Heavy Clothing at 20 yards This event repeats test event 2 but at the range
of 20 yards, measured from the muzzle to the front of the gelatin.
This test event assesses the effects of increased range and consequently
decreased velocity.
Test Event 8--Automobile Glass at 20 yards This event repeats test event 6 but at a range of 20 yards, measured from the muzzle to the front of the glass, and without the 15 degree offset. This shot is made from straight in front of the glass, simulating a shot at the driver of a car bearing down on the shooter. In addition to the above described series of test events, each cartridge is tested for velocity and accuracy. Twenty rounds are fired through a test barrel and twenty rounds are fired through the service weapon used in the penetration tests. Two ten-shot groups are fired from the test barrel,
and two ten-shot groups from the service weapon used, at 25 yards.
They are measured from centre to centre of the two most widely spaced holes,
averaged and reported.
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