The Spotlight: July 2002

By Jim Schatz, Heckler & Koch, Inc.

Puny Bullets by Dr. Martin L. Fackler
A Manufacturers Response

Dr. Fackler’s assessment and opinion concerning the lethality of small caliber PDW cartridges appeared in the previous issue of “Small Arms Review”. Heckler & Koch was offered the opportunity by SAR to respond to Dr. Fackler’s article. We hope our friends at FN will also choose to respond in kind in the interest of dialogue in what many experts believe is the most interesting recent development in small arms; Personal Defense Weapons.

Dr. Fackler is certainly experienced and well respected in the field of wound ballistics. We are however not aware that Dr. Fackler has actually tested the HK 4.6x30mm cartridge or the weapon itself, yet he is highly critical of the HK 4.6mm round. This is a pitfall that he warns others not to fall into. I am also not aware that Dr. Fackler has officially contacted HK with his concerns previously. We do welcome his expertise to this relatively new area of small arms development and intend to invite him to HK in the very near future for a full briefing on this weapons system.

Few will argue that these PDW rounds can compare to rifle calibers such as 5.56x45mm and 7.62x51mm or to a lesser degree handgun calibers in the areas of permanent and/or temporary tissue destruction or in muzzle energy. The HK 4.6x30mm cartridge was not designed to replace rifle cartridges. It was intended to replace pistol-caliber weapons, primarily those in caliber 9x19mm Parabellum and to be used for target engagements at realistic PDW ranges, that being less than 100 meters. Understanding the rationale for the development at HK of the 4.6mm round and HK PDW, now type-classified by the German military as the “MP7”, is key to understanding why HK has invested a great deal of our own IR&D funds on this addition to the relatively new category of individual weapons.

PDW’s actually are not new. The US armed forces have classified the M9 Pistol as a PDW for nearly 20 years since it’s adoption in fact, and still do. The problem with handgun calibers like 9mm Parabellum and .45 ACP and the hugely popular .40 S&W is that they do not defeat (penetrate) modern soft and hard military-issue body armor unless AP projectiles are employed. Handgun ammunition assembled using armor piercing projectiles are not issued to US forces or those of most other nations. AP projectiles also perform poorly against unprotected soft tissue as Dr. Fackler points out and thus are not the best all around choice for all targets. The other major concern with handguns as PDW’s is the low hit probability in the hands of the average user. Handgun marksmanship is difficult to master for many and a perishable skill for all; making hits on target, especially under the stress of an armed encounter under variable lighting conditions, a hard skill to maintain. These two issues are the driving force behind HK’s development of the MP7 and the 4.6mm cartridge and should be kept in mind during the following explanation of HK’s rationale for the design of our PDW “system”.

Contrary to Dr. Fackler’s claim that we “powerful arms companies with large advertising budgets” are forcing the concept of PDW’s on to the prospective users, this is simply not true in the case of Heckler & Koch. As is so often the case in the small arms community it was the user who petitioned the small arms industry to “push the stick” to address the important though often ignored deficiencies of conventional defensive military weapons. HK began its study on this subject in the early 1990’s in response to the NATO requirement D29 for a new PDW to replace 9x19mm handguns and sub guns. Like the weapons it might one-day replace it was to be lightweight, small and easily portable. Most importantly the new NATO PDW was to have a high degree of hit probability and the means to defeat the NATO CRISAT target, something that pistol-caliber handguns and submachine guns could not and cannot do with standard issue military FMJ ammunition.

HK began its effort devising a cartridge that would defeat the CRISAT target and yet impart only the absolute minimal amount of recoil to the shooters shoulder. The HK MP7 imparts about one third the recoil impulse of the 9mm Parabellum cartridge to the shooters shoulder when fired from an HK MP5 submachine gun yet it will defeat the current CRISAT target at distances out to and including 200 meters. In 1992 the CRISAT target was revised by the NATO panel from 48 layers of Kevlar to the current configuration, 20 layers of Kevlar covered with 1.6mm titanium plates and the HK PDW cartridge was modified by HK engineers to account for this change. This move was brought on by the proliferation of Soviet SPETsNAZ-style body armor, which has now found its way to most corners of the world into some very shady hands, to include military, para-military and criminal elements of some of the worlds’ most dangerous organizations. HK has thus exceeded the demands of the user and the NATO D29 PDW requirement with this new and continuing development.

Hit probability is the key to lethality. In the absence of any contact with the intended recipient the most modern high-performance projectile is still 100% ineffective. The NATO PDW is intended to be issued to support personnel primarily who are generally armed with pistol-caliber weapons. Armed with the HK MP7 these personnel can now effectively defend themselves against aggressors wearing modern body armor. Due to it’s low recoil impulse in semi auto fire and associated controllability on full auto fire, the fact that it can be shoulder-fired and has an all-weather day/night reflex sight the HK MP7 is highly effective for the common soldier due to it’s high degree of hit probability under all conditions without special and/or regular refresher training.

Even novice shooters can easily obtain repeated hits on targets out to 100 meters and beyond with a weapon such as the HK MP7. Given a handgun few could match that performance with any regularity even on targets located at just 25 meters.

Would all military combatants and law enforcement officers be better off in terms of maximum lethality with rifle-caliber assault rifles? Most definitely but for many reasons of portability, cost and issues of overpenetration an assault rifle or even submachine gun is inappropriate in most of the classic law enforcement and military support roles. The concept of the HK PDW is a weapon that is easily wearable by the user so it is immediately available when called upon, even as the wearer performs his or her normal duties of piloting an aircraft, loading ammunition, operating a radio or directing traffic. One of the most unfortunate aspects of the infamous 1986 Miami FBI shootout was that the FBI agents had available to them MP5 Submachine Guns in the trunks of their cars. However they were not immediately available when the unexpected shooting began. In most cases what the agents used in the firefight was what they were wearing and the handguns proved woefully ineffective against their very determined assailants inside the natural ballistic protection of an automobile, even though a few shots were perfectly placed by the agents with no immedite effect on their eventual assassins.

Dr. Fackler speaks to great lengths in his article about the use of PDW’s in law enforcement close-quarters combat. While this was not the primary purpose envisioned for the HK PDW a final report from 2001 on testing conducted on a prototype HK PDW and early pre-production ammunition by the Naval Surface Warfare Center (NSWC) Crane Division for US Army special operations forces concluded that “In a close range defensive (or offensive) engagement it appears that the PDW would be well suited to the use of shoulder mounted automatic burst fire” due to it’s controllability. The report goes on to state that “The PDW’s high rate of fire (950 rpm) combined with an aimed 5-10 round burst would significantly increase the likelihood of rapid incapacitation by increasing the chance for quick Central Nervous System (CSN) disruption”.

Dr. Fackler also refers numerous times to the lessons learned from the FBI’s tragic “Miami Shootout” and the post shooting Wound Ballistics seminars that concluded that shooting incapacitation results from a hit or hits to the central nervous system (brain, brain stem, spinal cord, etc.) or through blood loss. CSN incapacitation is near instant whereas incapacitation through blood loss, even with the destruction of the heart, can take up to 10 to 15 seconds, 50 seconds in some accounts, until oxygen is depleted from the bloodstream and brain. Permanent tissue destruction causes blood loss. Temporary cavities were deemed too unreliable and unpredictable for immediate incapacitation purposes, particularly those created by pistol-caliber ammunition.

Heckler & Koch has devised the MP7 to not only be able to penetrate ballistic protection on or around the intended target, such as vests, helmets and vehicle body panels and windshields, but allows the operators to easily hit the target in semi or burst fire with multiple rounds at ranges out to 200 meters. Each projectile has the capacity to both destroy tissue and organs and cause blood loss or to shut down the central nervous system by simple penetration of soft tissue and bone.

Dr. Fackler too often compares the HK 4.6mm projectile with other calibers that utilize conventional bullet designs. The projectile design of the HK PDW round (all 10 rounds in the 4.6mm ammo “family” in fact) is unique in that it is solid with no conventional core or jacket, similar in construction to proven dangerous game hunting bullets. The ball projectiles are solid steel or copper with an anti-friction coating (molycoat, copper wash). This insures near 100% weight retention of the relatively lightweight projectile which results in increased penetration through the human target. The long blunt tip and length to width ratio of the 4.6mm projectile insures early yawing in the target and the resultant tissue destruction at realistic PDW ranges (< 100 meters) greater than the 9x19mm projectile it was developed to replace. Results of extensive testing by two independent European test facilities confirm the lethality of the 4.6x30mm cartridge.

Conversely keeping the projectile weight down helps minimize recoil impulse and thus improves hit probability. Using current FBI test protocol the 4.6x30mm steel ball round fully penetrates the CRISAT target at 100 meters and yet penetrates into 20% ordnance gelatin (European standard) more than 6 inches and has more residual muzzle energy than a 124 grain 9mm Parabellum projectile. At 50 meters the 4.6mm steel ball round will penetrate more than 12 inches through an unprotected gelatin block (FBI standards require a minimum of 10-12 inches penetration to be effective, to reach vital organs). The 4.6mm steel ball round still perforates the CRISAT vest at 200 meters or two vests at 50 meters. As a result of the blunt tip the 4.6mm projectile resists deflection when firing against angled windshields and body panels. A special solid copper “Spoon Nose” projectile with angled tip and new “Sky Marshal” and hollow-point “Police” bullets reduce penetration on unprotected targets when overpenetration presents an operational concern around “friendlies” or within sensitive structures and vehicles.

High velocity rifle cartridges are very destructive. More so than pistol or the newer 4.6mm and 5.7mm PDW rounds. However they cannot be packaged in an easily portable weapon like today’s PDW’s. Even the smallest assault rifles are three times the size and weight of the HK MP7 and due to their 5-10 inch barrels lose a great deal of muzzle velocity and energy anyway while at the same time sharply increasing muzzle blast and flash. Thus in the case of the HK MP7 there is a compromise sought by the developers, one that obviously Dr. Fackler does not agree with. It is clear from his comments that not even the 5.56x45mm NATO (.223 Remington) cartridge is acceptable for law enforcement or CQB use, as quoting Dr. Fackler, “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 man-sized target)”. While maybe not THE most effective deer cartridge in the world the popularity of this round in countless armies and law enforcement organizations across the globe since the 1960’s, and the estimated tens of thousands of humans killed by this cartridge in military and law enforcement shootings, proves that it is a reliable and lethal cartridge against human aggressors.

Let us not fall into the same trap and limit the R&D into this new and promising category of small arms because of the age old controversies of “9mm vs. .45 ACP” and “5.56mm vs. 7.62mm”. It will be the users who will determine the success, or failure, of today’s modern Personal Defense Weapons like the HK MP7. This being said we also must agree with Dr. Fackler that the manufacturers must design these weapons and cartridges to meet or exceed the user requirements and refrain from promoting the weapon system for more than it is appropriate for. The experienced designers at Heckler & Koch would not be continuing the development of this system if it were not determined through sound calculations and extensive testing that it could perform its true function on the modern battlefield. The concept and development of the 4.6x30mm PDW cartridge originated in the mind of Wolfgang Katzmaier of HK GmbH, a brilliant design engineer with more than 40 years of experience at HK in advanced ballistics, weapon and cartridge design and testing.

In his article Dr. Fackler seemingly bases his entire assessment of the PDW concept, more specifically the HK MP7 PDW and the 4.6x30mm cartridge, on wound ballistics alone. There are many factors that must be considered, and weighed, when developing or adopting a new weapon/ammunition system. Factors such as weight, size, operator safety, ammunition compatibility, accuracy, reliability, portability and applicability to the mission or user group, etc. must all be considered by the developers. It is shortsighted to rule out a modern tactical tool like a PDW simply using only the area of wound ballistics as a ruler. Had this rationale been employed previously the famed M2HB machine gun might have been deemed “too heavy”, the MK19 “too inherently unsafe for the user”, the M3 Grease gun “to inaccurate” or the current M9 pistol and M16/M4 rifles “not lethal enough”.

In many ways the current PDW’s like the FN P90 and the HK MP7 are at the zenith of modern weapons design. They are small and highly portable, more so than any other shoulder-fired weapon fielded previously yet they are both lethal and capable of dealing with targets protected by modern body armor. They offer increased hit probability over rifle or pistol-caliber weapons and at greater ranges. In fact the NSWC Crane report on the HK PDW concluded that “The PDW weighs little more than a standard military defensive handgun and may be carried in a leg holster in a similar fashion to a handgun. However, it can be fired from the shoulder and sighted like a rifle providing a significant advantage in speed and range of engagement over an enemy armed only with a handgun and a virtually equal engagement capability (ability to hit) against a typical assault rifle out to 100 meters”. The report goes on to state that the 100-meter accuracy (<4 inches) of the HK PDW rivaled that of a standard M4A1 Carbine. More rounds stowed on board in high-capacity magazines is a standard feature of modern PDW’s while the overall system weight is considerably less, greater than 50% for the HK MP7 compared to the M4 Carbine or HK MP5A3 submachine gun. Most importantly due to the small size and weight of the HK MP7 it can be worn by the user as one would carry a handgun and thus is always immediately available when needed.

Are there better weapons for other roles? Yes. Are there better weapons for close-in (<100 meters) personal protection of the average user? We do not think so but it is the user, not the industry or academia, that in time will determine that.

Remember for HK this is a work in progress. The MP7 and 4.6mm ammunition family is still in development, though in the final stages of refinement with series production scheduled to commence in mid-2002. HK is working very closely with the user community, special operations forces, military ordnance facilities, independent test laboratories and ammunition makers to insure that what the user wants is what they receive. From the initial response by the user community to the Heckler & Koch MP7 Personal Defense Weapon system we are convinced that they, unlike Dr. Fackler, look at the PDW from all aspects not just that of wound ballistics. It is fact that these same users are confident that within its intended role the HK MP7 and 4.6x30mm cartridge is lethal enough to get the job done “when the rubber hits the road”.

We would like to thank Dan Shea and “Small Arms Review” and Dr. Fackler for the opportunity to weigh in on this important if not arguably controversial issue.

Jim Schatz, Heckler & Koch, Inc.

This article first appeared in Small Arms Review V5N10 (July 2002)
and was posted online on January 31, 2014


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