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Tactical Briefs (Volume 2, Number 1)Updated 6-25-99: Added Wound Profile Illustrations to the article: "Wounding Effects of the U.S. Military M193 (M16A1) and M855 (M16A2) Bullet Cartridges." PMC El Dorado Starfire Ammunition Performance Data
The following table contains bullet performance data provided by PMC El Dorado Cartridge Corp., Boulder City, NV, for their entire line of Starfire ammunition.
According to PMC, these bullets expand up to 1.5 times their unfired diameter.
The deepest penetration depths will be obtained when firing these cartridges from compact handguns. The shorter the barrel length, the less velocity is developed before the bullet exits the muzzle. Less velocity usually produces less bullet expansion, which in turn increases bullet penetration. Compact handguns with barrel lengths less than 4-inches will probably produce the deepest penetration. Handguns with barrel lengths of 5- to 6-inches will probably produce the least amount of penetration. Handguns with barrel lengths in between these two extremes will probably fall somewhere in the middle in terms of penetration.
Cartridge Bullet Weight Penetration Depth .380 ACP 95-grains 8-10 inches 9mm Luger 124-grains 10-12 inches .40 S&W 155 grain 10-12 inches .40 S&W 180-grains 10-12 inches 10mm Auto 180-grains 10-12 inches .45 ACP 230 grains 10-12 inches .38 Special 125-grains 8-10 inches .357 Magnum 150-grains 10-12 inches .44 Magnum 240-grains 12-14 inches
ANT-6 Anatomically Correct Target
Law Enforcement Targets is offering a new life-size anatomically correct silhouette target that is similar to its ANT-5 target we reported about in Tactical Briefs, September 1998. The ANT-6 target consists of a life-size gray-scale photograph of a male attacker whose major internal organs are outlined in a subdued medium-light gray. The "organs" are not readily visible beyond 3-yards, depending on lighting.
The advantages of the ANT-5 and ANT-6 targets are that both teach personal defense shooters about proper shot placement. The feedback provided by locating bullet "wound tracks" in relation to vital body structures allows shooters to evaluate the potential effectiveness of their hits. These targets appear to be great training aids for private citizens, armed private security guards, law enforcement and military.
Click here to view photographs of the ANT-6 target.
Click here to visit the Law Enforcement Targets web site.
Wounding Effects of the U.S. Military M193 (M16A1) and M855 (M16A2) Bullet Cartridges
Exaggerated descriptions of the wounding effects of the M16 rifle bullet flourish as great works of urban lore. One fable describes a bullet that tumbles end-over-end in flight as soon as it exits the muzzle of the rifle. Another legend provides a dramatic account of an unstable, super-high velocity bullet that tumbles and chews its way through flesh like a buzz saw. Although there appears to be a tinge of half-truth behind these entertaining and awe-inspiring mythical tales, these stories do not represent an accurate description of the wounding characteristics of the M16 bullet.
When the M16 cartridge is fired and the bullet is propelled down the bore, the bores rifling imparts a gyroscopic spin to the bullet. This gyroscopic rotation is needed to maintain point forward stabilization of the bullet as it flies through the air. This method of bullet stabilization is identical to the rotational spin applied to a football when thrown by a quarterback (American football).
The Earths gaseous atmosphere is approximately 400 times less dense than the body's soft tissues. When the M16 bullet strikes and plows into the body, the rotational spin that stabilized its flight through the air is insufficient to maintain its stability as it flies through dense tissue. The bullet typically penetrates point forward for approximately 4-5 inches before it begins to seek a state of stability in the body.
The bullets pointed shape makes it heavier at its base than its nose, producing a center of gravity that is located aft of its longitudinal centerline. When the bullet hits the body and penetrates, the bullet attempts to rotate 180 degrees around its center of gravity to achieve a base forward orientation. This backwards orientation is the bullets stable position in tissue because it places the center of gravity forward.
As the bullet yaws through 90 degrees and is traveling sideways through flesh, the stress of tissue resistance to bullet passage can overpower the physical integrity of the bullet. The bullet has a groove around its midsection called a cannelure. The purpose of the cannelure is to permit the mouth of the cartridge case to be crimped tightly against the bullet shank to hold it firmly to the case. The cannelure weakens the structural integrity of the bullet's copper jacket.
At distances of 100 yards and under, when the bullet hits the body and yaws through 90 degrees, the stresses on the bullet cause the leading edge to flatten, extruding lead core out the open base, just before it breaks apart at the cannelure. The portion of the bullet forward of the cannelure, the nose, usually remains in one piece and retains about 60 percent of the bullet's original weight. The portion of the bullet aft of the cannelure, the base, violently disintegrates into multiple lead core and copper jacket fragments, which penetrate up to 3-inches radially outward from the wound track. The fragments perforate and weaken the surrounding tissues allowing the subsequent temporary cavity to forcibly stretch and rip open the multiple small wound tracks produced by the fragments. The resulting wound is similar to one produced by a commercial expanding bullet used for varmint hunting, however the maximum tissue damage produced by the military bullet is located at a greater penetration depth.
(The increased wounding effects produced by bullet fragmentation were not well understood until the mid-1980s. Therefore the wounding effects of the original M16 rifle bullet were not an intentional U.S. military design characteristic.)
At distances between 100-200 yards the bullet commonly breaks in half at the cannelure forming two large penetrating fragments, the nose and base.
At distances beyond 200 yards the bullet usually remains intact due to velocity decay. It simply yaws 180 degrees to penetrate backwards through the body.
Both the M193 and M855 bullets demonstrate similar terminal performance as described above, when fired from rifles fitted with a 20-inch or longer barrel.
Shooting the M193 or M855 from a rifle with a barrel length less than 14.5-inches produces insufficient muzzle velocity to achieve the terminal performance described above. A rifle fitted with a 14.5-inch barrel is adequate for close-quarters battle. For engagements anticipated at greater than room distance but less than 100 yards, a rifle fitted with a 16.5-inch barrel should be employed to ensure sufficient velocity.
The older 55-grain M193 (M16A1) cartridge is not sensitive to rifling twist rate and can be fired in rifles with 1:12, 1:9 and 1:7 rates of twist. However, the newer M855 (M16A2) cartridge is best used with a rifling twist rate of 1:7 or 1:9. When the M855 is fired in a rifle with a slower rate of twist the longer 62-grain bullet can yaw up to 70 degrees in free trajectory through the air, substantially degrading accuracy.
The wound ballistics of the U.S. military Olin M193/Winchester 55 grain FMJ (X223R1 or Q3131) and green tip U.S. military Olin M855/Winchester 62 grain FMJ (RA556M855) cartridges makes them an adequate choice for use against violent criminal offenders.
Additional testing has indicated that errant bullets (military FMJ and commercial .223 Remington JSP/JHP) which do not hit an attacker appear to penetrate fewer walls and other common building materials than stray handgun bullets.
Click here to view wound profile illustrations of the M193 and M855 bullets.
Fackler, Martin L.: "Wounding Patterns of Military Rifle Bullets." International Defense Review 1/1989, 59-64.
Fackler, Martin L. : "Physics of Missile Injuries," Evaluation and Management of Trauma, Chapter 2. Appleton-Century-Crofts, Norwalk, CT; 1987, p. 35.
Roberts, Gary K, D.D.S.: "The Wounding Effects of 5.56MM/.223 Law Enforcement General Purpose Shoulder Fired Carbines Compared with 12 GA. Shotguns and Pistol Caliber Weapons Using 10% Ordnance Gelatin as a Tissue Simulant." Wound Ballistics Review 3(4), 16-28; 1998.
Speer 9mm 124-grain +P Gold Dot Ammunition Distributor
Speer markets its 9mm 124-grain +P Gold Dot cartridge to law enforcement. It currently is not offered to private citizens through the commercial market. (This might change in the future.) However we've located an ammunition distributor who's recently been authorized by Speer to sell the +P cartridge, by the box, to private citizens.
Be advised that we recommend the +P cartridge for use only in compact handguns with barrel lengths less than 4-inches. The 124-grain Gold Dot bullet seems to provide optimal penetration and expansion performance when propelled at approximately 1150 fps. The +P load is designed to propel its bullet at 1220 fps, and this could lead to over-expansion and under-penetration when fired out of a handgun with a barrel length that is 4-inches or longer.
When fired from a handgun that has a barrel length less than 4-inches, the +P bullet is unable to reach its full velocity potential of 1220 fps before it exits the muzzle. When we tested this load last August using a handgun with a 3.4-inch barrel, the bullet's average velocity was 1155 fps, the ideal velocity for optimum performance as designed by Speer.
If you have a 9mm handgun, and you're not comfortable loading it with 147-grain bullets for personal defense, the Speer 124-grain Gold Dot is an acceptable alternative choice. If the barrel length of your handgun is 4-inches or longer, we suggest you use the standard velocity (1150 fps) load. If your handgun has a barrel length less than 4-inches, we suggest you use the +P (1220 fps) load.
Speer 9mm 124-grain +P Gold Dot ammunition (Speer product number 53617, 50 rounds) can be ordered by private citizens from:
The Hunting Shack
P.O. Box 7465
Missoula MT 59607
Federal Personal Defense Shotshell Performance Data
With clear weather descending upon us for the first time in several weeks here in the Seattle/Puget Sound region, we finally made it out to the shooting range to test Federal Cartridge Company's new 12 gauge Personal Defense Shotshell (product number PD12-2). We fired 6 shotshells: 3 rounds to examine shot penetration performance and 3 rounds to observe shot patterning performance. We also disassembled a live shotshell to examine its internal components.
Federal introduced its Personal Defense Shotshell last year. Its marketed as a "low recoil, optimized pattern" 2 3/4-inch shotshell. The 1998 catalog states the 1 1/4-ounce #2 shot charge is propelled at a muzzle velocity of 1140 fps.
(A 20 gauge Personal Defense Shotshell is also available, product number PS20-2, which contains 1-ounce of #2 shot propelled at 1140 fps. We expect the 20 gauge load to perform very similar to the 12 gauge load we tested.)
The Personal Defense Shotshell is packaged in cartons of ten shotshells, and costs about $10.00/carton. The packaging contains the following marketing claims:
"Premium Personal Defense Shotshell Ammunition features a specially engineered payload that opens rapidly and offers optimized penetration. The amount of recoil has been reduced to improve firearms control."
The bottom of the carton has an illustration of a cutaway shotshell showing the internal components, and lists four benefits of the Personal Defense Shotshell design:
- Federals own extruded plastic hull made for quality performance.
- Specially tailored shot load optimizes penetration.
- Optimized patterns provide greater effectiveness at close range.
- Loaded for low recoil.
We used the water-filled half-gallon cardboard milk carton method to test pellet penetration. This procedure is described in Tactical Briefs #3. Briefly, several water-filled milk cartons were lined-up in a row and a single shotshell was fired into the row of cartons. The number of cartons penetrated by the pellets was counted, and the pellets remaining in each carton were recovered and counted. Pellet penetration depths were determined by counting the number of cartons penetrated and multiplying by 2.5.
An Oehler model 35P proof chronograph was positioned in front of the row of milk cartons to measure the velocity of the shot cluster as it exited the muzzle of the shotgun and before it impacted the first carton. The shotgun used was a pump-action Remington model 870 fitted with a Remington factory 18-inch modified-cylinder choke smoothbore barrel with bead sight. The barrel has been modified by Vang Comp Systems to tighten shot patterns and reduce recoil. The distance from the muzzle to the first milk carton in the row was approximately 12-15 feet.
Partly due to the wide dispersal of the shot pattern, not all the shot was recovered from the cartons. Some pellets exited out the sides of the cartons and continued downrange, while others were washed out of the cartons and off the test stand by the sudden wash of water escaping out the damaged milk cartons.
The shot penetrated a maximum of 4 water-filled milk cartons. In all three tests the most shot was recovered from carton #3.
The penetration test results are as follows:
Shot #1. Velocity 1000 fps: Carton # # Pellets Recovered 1 3 pellets 2 15 pellets 3 55 pellets 4 2 pellets Remarks: Shotcup recovered from carton #2. Plastic and cardboard wads were recovered from benchtop.
Shot #2. Velocity 1089 fps: Carton # # Pellets Recovered 1 0 pellets 2 0 pellets 3 36 pellets 4 8 pellets Remarks: Shotcup and wads recovered from carton #3.
Shot #3. Velocity 1047 fps: Carton # # Pellets Recovered 1 0 pellets 2 0 pellets 3 35 pellets 4 7 pellets Remarks: Shotcup and wads recovered from carton #2.
The majority of the shot was consistently recovered from carton #3, and this indicates that most of the shot penetrates approximately 5- to 7 1/2- inches. A few pellets penetrated to carton #4 to achieve a maximum penetration depth of between 7 1/2- to 10-inches.
Click here to view photographs of our test results.
In our October 1998 Tactical Briefs, we mentioned a photograph on page 19 of the 1998 Federal catalog that shows a block of ordnance gelatin into which the Personal Defense Shotshell was fired. We complained about a lack of a measuring scale in the photograph that would allow viewers to determine penetration depth of the shot in the gelatin. Based on our test results, we feel our original interpretation of the penetration depth of the pellets is wrong.
Upon re-examination of the photograph it appears the gelatin block is approximately 8-inches deep. We originally believed the block to be 6-inches deep (the shotshell being fired into the the side of a standard FBI test protocol gelatin block with a dimension of 6x6x16-inches), and showed most of the pellets penetrating between 4- and 5-inches, with a few pellets penetrating beyond 5-inches.
Whereas, if the block of gelatin is 8-inches deep, the results pictured in the Federal catalog more closely correlates with our test results. Most of the pellets in the Federal catalog photograph appear to penetrate between 5- and 7-inches with a few penetrating just slightly beyond 7-inches.
This penetration performance more closely matches the data in Figure 10-8, Lead Alloy Sphere Penetration Depth, in Duncan MacPherson's book Bullet Penetration. MacPherson's figure shows a maximum penetration depth potential approximately 7-inches for #2 lead birdshot propelled at 1140 fps.
However, the velocity of our pellets was approximately 100 fps slower than Federals 1140 fps design velocity. Were going to speculate that the temporary cavity produced by the pellets in front of the shot cluster cleared the way, so to speak, by churning-up and propelling water out of the initial path of following pellets. This would give the appearance that the pellets are capable of penetrating deeper than their maximum potential. The pellets near the back of the shot cluster apparently did not make direct penetrating contact with the water for the first one to two inches after passing through the front wall of the first milk carton. This is purely conjecture on our part, but it seems to be a reasonable explanation for the penetration performance observed.
The recovered shot was badly deformed. Several pellets showed signs of contact with the bore, causing flattening of the pellets and abrasive removal of the copper-plating to expose underlying lead. Until we destructively disassembled an unfired shotshell to see for ourselves, the extent of pellet deformation appeared similar to a compressed shot charge.
An X-acto knife was used to cut open the hull of an unfired shotshell. We counted 104 pieces of undeformed spherical copper-plated #2 lead shot. Using an RCBS model 10-10 powder scale, the shot charge measured 533-grains, just slightly less than 1 1/4 ounces (547-grains).
The 1 1/8-inch long plastic shotcup is a unique design. It has a 1/4-inch wide hollow post protruding out the center. It has no petals to protect the shot from contact with the bore. The base of the shotcup, which makes bore contact, measures 7/16-inch long. The design appears intended to maximize shot dispersal upon exit from the muzzle. The shotcup sits atop a disk-like cardboard wad. Underneath the cardboard wad is a plastic wad of similar thickness. The plastic wad sits atop the powder charge.
We fired three test patterns. The distance from the muzzle to each target was 10-feet. All three shot patterns measured approximately 5-inches in diameter, with even radial dispersion of the shot. The shot pattern is accurately centered around the point of aim.
For comparison purposes, we fired a Dove and Quail load, consisting of 1-ounce of #8 lead shot. The pattern of this load was approximately 2 1/2-inches in diameter at 10-feet.
It appears the Personal Defense Shotshell has a pellet spread rate of approximately 2-inches for every yard of travel from the muzzle, which is twice the spread rate for conventional shotshell loads when fired from an 18-inch modified cylinder choke barrel.
Recoil of the Personal Defense Shotshell was similar to the Dove and Quail load, which has a lighter shot charge.
While the Federal Personal Defense Shotshell does not meet the IWBAs 12- to 18-inch penetration depth guidelines, it is nonetheless adequate to use as the first one or two shots to be fired at an aggressor, as long as deeper penetrating buckshot is available for subsequent shots, if needed. The extreme spread of the shot pattern makes it unacceptable for anything other than room-distance, close-quarters, in-home personal defense use.
Cotey, Gus Jr.: "Number 1 Buckshot, the Number 1 Choice." Wound Ballistics Review, 2(4); 10-18, 1996.
MacPherson, Duncan: Bullet Penetration - Modeling the Dynamics and Incapacitation Resulting from Wound Trauma. Ballistic Publications, El Segundo, CA; 1994.
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