FBI Ballistic Test Protocol

The following information was forwarded to me from someone on the API list.  Note that this is only the protocol (methodology) of the FBI test, not the results they achieved with various types of ammunition.  I have no way to access and post that information.  Sorry.

FBI Ballistic Test Protocol:

Briefly, the performance standards are simple. 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 make the hole bigger. This increases the amount of vital tissue damaged, increases the chance of damaging vital tissue 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 hemorrhage 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 (i.e., one pound of gelatin to 9 pounds of water). The gelatin is stored at 4 Centigrade (39.2 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. The 10 % gelatin has been correlated against the actual results of over 200 shooting  incidents. Each gelatin block is calibrated before use to insure its composition is within defined parameters. Copies of the test protocol are available upon request for those interested in duplication the testing or reviewing the procedures in greater detail.

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 insure containment of the bullet's total 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 tests 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 1: 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 expansion in this test.  Rounds which do not meet the standards against bare gelatin tend to be unreliable in the more practical test events that follow.
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 10 ounce down comforter in a 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 galvanized 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 10 feet measured from the muzzle to the front of the first piece of steel. Light Clothing is one layer of the above described T-shirt material and one layer of the above described cotton shirt material, and is used as indicated in all subsequent test events.

The steel used 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 that 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 and placed 18 inches behind the rear most piece of gypsum. The shot is made at a distance of ten feet, measured from the muzzle to the front 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 placed 18 inches behind the rear surface of the plywood. The shot is made at a distance of 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 15x18 inches is set at an angle of 45 to the horizontal. The line of bore of the weapon is offset 15 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 placed 18 inches behind the glass. The shot is made at a distance of ten feet, measured from the muzzle to the center of the glass pane. This test event with its two angles simulates a shot taken at the driver of a car from the left front quarter of the vehicle, and not directly in front of it.
Test Event 7: Heavy Clothing at 20 yards This event repeats Test Event 2 but at a 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 offset. The 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. All velocities are measured and reported.

Two ten-shot groups are fired from the test barrel, and two from the service weapon used, at 25 yards. They are measured from center to center of the two most widely spaced holes, averaged and reported.

Test barrel results demonstrate a round's potential independent of any weapon factors which can affect performance. Test barrel results are the purest measure of inherent capability for accuracy and velocity.  Repeating these tests with a service weapon shows how well the cartridge/weapon combination may realize that potential.

 

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