The Spotlight: June 2002

By Martin L. Fackler, MD

From time to time, SAR receives a no holds barred, against the grain editorial, and we have finally found the correct forum for this-”The Spotlight”. Herewith, we present the opening salvo from Dr. Martin Fackler, the president of the International Wound Ballistics Association. Dr. Fackler’s credentials are impeccable in his field, and he raises some concerns here that are of great interest to our readers. We are prepared to present opposing or supportive views in the next issue of SAR. Be sure not to miss this controversy as it unfolds- the newest and most innovative small arms on the scene come under professional scrutiny, and we are witness to this debate- Dan

Manufacturers apparently understand that it is easy to sell people on ideas they want to believe. “Personal Defense Weapons” (PDWs) are cute. They are very lightweight, no strain to carry, and have essentially no recoil to contend with. They are fun to shoot. Only the most firearms illiterate, however, could believe that the bullets fired by these weapons could provide reliable protection against a 250-pound armed and raging felon.

My experience as a wound ballistics researcher and consultant for more than two decades has led me to the unfortunate conclusion that very few of those who would be expected to understand wound ballistics actually have an adequate grasp of the subject. My experience, of the past decade, with the PDW problem strongly reinforces that conclusion.

The history of firearms development has been blemished repeatedly by ordnance engineers designing ineffective weapons, which got their users killed. Bullet developers are usually adept at internal and external ballistics, as well as at that part of terminal ballistics dealing with penetration of hard targets such as armor. Unfortunately, wound ballistics, the study of bullet effects on the living body, including causes of lethality and the immediacy of incapacitation, has never been their strong point. When the new smaller-caliber, higher-velocity bullets made possible by the hard-metal-jacketing of lead cores were introduced on the battlefields of the world, it took the sacrifice of soldiers to demonstrate the ineffectiveness of these bullets in stopping the aggression of their adversaries. In India, in 1895, and in Somaliland, in 1903, countless British infantrymen were chopped up or speared because their nondeforming bullets had little effect on charging and determined tribesmen. US Armed Forces suffered from the same lack of bullet effectiveness in the Spanish-American war.

One would think that ordnance engineers would have learned, from the historical record, that bullet effectiveness cannot be determined from bullet velocity alone. Yet again, three-quarters of a century later, we had to sacrifice two FBI agents killed and five seriously wounded, in the “Miami Shootout” of 1986, to prove to ordnance engineers that they needed help from persons trained in wound ballistics to determine the effect of various bullets on the living human body.

The foregoing might not be too surprising, considering that wound ballistics didn’t develop into an authentic science until the 1980s. Now, however, we have a tissue simulant that has been calibrated against living tissue and a method for reproducing and illustrating a bullet’s disruption pattern — the wound profile. Law enforcement organizations serious about determining the best bullets to protect their officers (FBI, RCMP, CHP, LAPD, etc.), as well as major American bullet manufacturers, have been using 10% ordnance gelatin to test bullets for the past decade. As a result, law enforcement officers are currently being furnished the most effective handgun bullets ever developed. The velocity of the overwhelming majority of these bullets is subsonic - considerably lower than the velocity of law enforcement bullets in the 1970s. We should not, therefore, have to relearn, one more time, the same painful historical lesson about the inefficiency of excessive bullet velocity. But alas, the PDWs are now being thrust upon us. With them emerges, anew, the inadequate bullet problem. This time we have the scientific methods to avoid disaster without having to sacrifice the military or police personnel that exposing inadequate bullets has cost us in the past. It appears, however, that science, common sense, and experience are being pushed aside by powerful arms companies with large advertising budgets.

About 1989, Fabrique Nationale Herstal (FN) introduced the first version of their P90. Apparently occupied with developing this weapon, FN failed to notice that, simultaneously with the P90’s development, major wound ballistics errors of the past were being corrected. That was a colossal stroke of bad luck for them. Just as it had been shown (valid and reproducible bullet testing, analysis of the FBI’s “Miami Shootout,” etc.) that increasing a handgun bullet’s velocity by lessening its weight decreases its potential to incapacitate the human target, FN introduced a very lightweight bullet at a higher-than-usual velocity.

The first FN 5.7x28 mm P90 bullet weighed 23 grains and was 2.4 cm (0.94 inches) long. Knowledgeable readers will readily recognize that a .22 caliber bullet, nearly an inch long, should weigh about 80 grains, not 23. But the core in these early bullets was made of plastic. The current P90 bullet weighs 31 grains, and its length has been shortened to 2.1 cm (0.83 inches). That is still too light for a “real” bullet. Now its core is mostly aluminum (at least it’s better than plastic). Despite the changes in its bullet, and absurd exaggerations of its capabilities by FN (claiming it makes a larger wound than a .44 Magnum HP bullet) and by the gun writers who have “evaluated” it (claiming its wounding capacity to be equal to the M16), the P90 has hung around for more than a decade without any notable success.

FN has recently been joined, in the PDW arena, by the firm of Heckler & Koch. The bullet of their caliber 4.6x30mm HK MP7 is even smaller than that of the P90: its .18 caliber bullet weighs 24.7 grains (to put this in perspective, a .22 Short bullet weighs 29 grains). One must wonder whether Heckler & Koch was inspired to develop the HK MP7 because some military and law enforcement groups purchased their HK53 chambered for the 5.56x45mm NATO cartridge and furnished with a ridiculously short 8.31-inch barrel. I suppose any group that would buy a medium-power varmint rifle, with half its barrel cut off, and think it adequate for use against the human target is so wound ballistics illiterate that they might be sold anything.

This group of weapons, with tiny bullets in the .22 Short weight range, possessing less wounding capacity than the .22 rimfire magnum bullet, has been given the “catchy” name “Personal Defense Weapons” apparently to make them to appear to be something exceptional - and to direct the attention of potential purchasers to their name, diverting it from their woefully deficient wounding capacity.

PDW bullet developers have apparently forgotten that their PDW bullets produce temporary cavities of only about three inches in diameter; and it is well understood that temporary cavities smaller than about five inches in diameter cannot be relied upon to add significantly to a bullet’s wounding capacity on a human target. Perhaps they need to be reminded that bullets injure by disrupting body tissue; and with such negligible temporary cavities, the only tissue the PDW bullets can disrupt is what they strike. The amount of tissue these PDW bullets strike is limited by their size. The FBI’s method of comparing the amount of tissue disruption caused by various bullets compares the bullets’ cross sectional areas (calculated from the formula pi x the square of the bullet’s radius). This means that if one bullet’s diameter is twice that of another, it strikes four times as much tissue. The P90’s .22 caliber bullet, traveling point forward, can strike only 0.038 square inches of tissue as it penetrates. The HK MP7’s .18 caliber bullet can strike only 0.025 square inches. When compared to the 0.1 square inches a 9 mm FMJ bullet strikes, or the 0.16 square inches a .45 ACP FMJ bullet disrupts as it penetrates, the hole size produced by the tiny PDW bullets looks pretty puny. And this comparison is just against the non-deforming military-type FMJ bullets.

Initially, the PDWs appeared to be aimed at the military market. For the military, often any wound at all is sufficient cause for an enemy soldier to retire from the field of battle. Perhaps the tiny PDW bullets, with only three-fourths the momentum of a .22 rimfire magnum bullet, might be of some use - if limited strictly to the type of warfare in which troops are not engaged in close-quarters combat.

Now, however, the PDWs are being marketed to law enforcement “for entry work.” This could prove disastrous. Law enforcement officers often face armed violent criminals at close range. They need a bullet capable of disrupting enough tissue to have a good chance of rapidly incapacitating violent armed criminals. The hole size (tissue disruption) comparison gets much more lopsided here. Law enforcement uses hollow-point handgun bullets, which expand and increase the size of the hole they make. The PDW bullets do not expand. Compare the hole diameters calculated above for the two PDW bullets with the 0.34 square inches produced by the expanded 9mm bullet and the 0.5 square inch hole made by the .45 ACP HP bullet. In case these numbers are not crystal clear — they show that a .45 ACP HP bullet destroys up to 20 times as much tissue as the .18 caliber PDW bullet does.

Manufacturers’ advertising claims that PDW bullets are effective out to 200 meters, and implies that our current handgun bullets are not. Comparing the momentum and energy of the PDW bullets, at the muzzle, with that of the 9 mm Parabellum: the 9 mm bullet starts out with about 10% more energy but 2.3 times as much momentum. And this might come as a surprise to the layman, but should not to those conversant with basic external ballistics: the 9 mm handgun bullet’s advantage, in both energy and momentum, increases with distance. The higher the velocity and the lower the weight of a bullet, the more rapidly it loses its velocity over distance. This is a basic principle of external ballistics. Due to the PDW bullets’ very light weight, and relatively high velocity, they lose about one fourth of their velocity in their first 100 meters of travel - and almost that much in their second 100 meters. So the implied advantage of the PDWs over handguns “out to 200 meters” is inconsistent with the facts of external ballistics. For projectiles that do not produce large enough temporary cavities to add significantly to their effect (both handgun and PDW bullets are in that group), the bullet’s momentum is a far more accurate measure of its tissue disruption potential than is its energy - and that is a basic principle of wound ballistics. By the time both projectiles have reached 100 meters, the 9 mm bullet has about 2.5 times as much momentum as does the PDW bullet. The wounds produced by the PDW bullets compare poorly to those produced by handgun bullets at the muzzle - and compare even more poorly at 200 meters.

It is unfortunate that most who depend upon firearms to defend their lives and the lives of others, as well as most who study firearms and write about them, possess little knowledge of wound ballistics. Wound ballistics, the science of projectiles interacting with the body, deals with the end result, toward which all the work and study with firearms and their use is aimed. Without a suitable wound ballistics result, all else is for naught. The following brief “common sense” overview of wound ballistics should help interested readers to support, or expose as false, many of the advertisements regarding bullet effects to which they are subjected. To get a reasonable estimate of a new bullet’s potential, compare its mass and its velocity with other existing bullets. Then consider the animals against which the known bullets have proven effective. The 7.62x51mm NATO rifle bullet is the civilian .308 Winchester: it is effective for shooting essentially all North American big game, including moose, elk, and grizzly bear. The 5.56x45mm NATO rifle bullet is the civilian .223 Remington: it is a “varmint” cartridge, used effectively for shooting woodchucks, crows, and coyotes. Please note that the .223 Remington bullet is prohibited for shooting deer in most states. It lacks the tissue disruption capacity needed to prove reliably lethal on deer (generally a man-sized target). Finally, the PDW bullets. They have no civilian equivalent. They can be compared to the .22 caliber Winchester rimfire magnum bullet. This rimfire bullet is effective on squirrels, crows, opossums, and on woodchucks at ranges under 150 yards.

As shown in the above comparisons, the PDW bullets are considerably outclassed by the standard military FMJ handgun bullets. When compared to the modern well-constructed hollow-point handgun bullets used by the police, the PDW bullets aren’t even in the same ballpark. By no stretch of the imagination is the PDW bullet adequate for law enforcement work: its use is likely to get police officers killed.

I have yet to see, in any publication other than the Wound Ballistics Review, a single word of doubt about these weapons. Well known gun magazines have turned down letters, and even refused to publish invited articles, that did not laud the PDWs. I have presented the problem from 1) the historical perspective, 2) the minuscule hole the PDW bullets are capable of producing, 3) the minuscule amount of momentum they possess, and 4) the comparison of PDW bullets to the known capabilities of similar bullets. The conclusions, on all four counts, are undeniable and highly supportive of one another. These pipsqueak PDW projectiles are so puny for anything more pressing than popping rats in the dump, that the popular gun press could provide a necessary public service by providing a warning to the law enforcement community of the PDW bullet’s paltry potential before it is too late.

Don’t miss the industry response in the next issue of SAR. If you have a professional opinion to add to this debate, please let us know, and submit it for our consideration.

This article first appeared in Small Arms Review V5N9 (June 2002)
and was posted online on February 14, 2014


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