Time for a Change U.S. Military Small Arms Ammunition Failures and Solutions NDIA Dallas, TX 21 May 2008 Gary K. Roberts, LCDR, USNR Author’s Background & Qualifications Dr. Roberts is currently on staff at Stanford University Medical Center; this is a large teaching hospital and Level I Trauma center were he performs hospital dentistry and surgery. After completing his residency at Navy Hospital Oakland in 1989 while on active military duty, he studied at the Army Wound Ballistic Research Laboratory at the Letterman Army Institute of Research and became one of the first members of the International Wound Ballistic Association. Since then, he has been tasked with performing military, law enforcement, and privately funded independent wound ballistic testing and analysis. He remains a Navy Reserve officer and has recently served on the Joint Service Wound Ballistic IPT, as well as being a consultant to the Joint FBI-USMC munitions testing program and the TSWG MURG program. He is frequently asked to provide wound ballistic technical assistance to numerous U.S. and allied SOF units and organizations. In addition, he is a technical advisor to the Association of Firearms and Toolmark Examiners, as well as to a variety of Federal, State, and municipal law enforcement agencies. He has been a sworn Reserve Police Officer in the San Francisco Bay Area, where he now he serves in an LE training role. 11.. TTrraaiinniinngg……aanndd MMoorree TTrraaiinniinngg 22.. RReelliiaabbllee aanndd DDuurraabbllee WWeeaappoonn SSyysstteemm 33.. AAmmmmuunniittiioonn TTeerrmmiinnaall PPeerrffoorrmmaannccee The first two items must be fully and adequately addressed before the third item becomes a serious concern… What’s Wrong With This Picture? In 1940, the prototype P51 Mustang successfully flew just 178 days after the initial order had been placed. Now in the 21st century, despite the efforts of many smart folks, few small arms improvements seem to get rapidly completed and expediently fielded--there is a significant gap between what we KNOW and what we actually DO for our warriors. If such glacial procurement had occurred during WWII, the war would have ended before any new weapons were fielded. SALVO, SPIW, 6 mm SAW, ACR, XM29, XM8…even with modern engineering, CAD/CAM techniques, and new materials many proposed U.S. small arms and ammunition improvements cost tens of millions of dollars, years of RDT&E, and then rarely seem to ever actually reach the field. Millions of dollars are poured into next generation small arms technologies with no near-term potential to improve combat capability, like caseless, telescoping, snd air-burst ammo, while simple innovative incremental advances that can immediately make an impact in combat operations, like barrier blind ammunition and intermediate calibers, get minimal funding or are ignored. DOD replaces computer hardware and software every 3 or 4 years, yet does not offer the same type of incremental improvements for small arms weapons and ammunition, despite similar costs. The sacred alter of “green” ammo has sucked up tens of millions of dollars over many years in the nebulous pursuit of “non-toxic” ammunition, yet with a few COTS exceptions, has not resulted in any improvements in ammunition reliability, accuracy, or terminal performance--the factors that actually help win fights. Overly complex, fundamentally flawed computer modeling and excessive statistical manipulations that don’t reflect reality are often used to try and predict military ammunition terminal performance and “lethality” instead of the more common sense approach using the physiological damage based methodology proven to closely correlate with numerous actual shooting incidents in over two decades use by law enforcement agencies and wound ballistic researchers. The United States made several major missteps in its search for the ideal combat rifle caliber. In the late 1920’s, the U.S. Army selected the .276 Pederson caliber produced by Frankford Arsenal as the best caliber for a new semi-automatic rifle. The .276 fired a 125 gr bullet at approximately 2700 f/s. Ordnance trials determined that John Garand’s new .276 caliber T3E2 rifle was an ideal combat weapon, however, development of the .276 rifle was halted in 1932 because of the large remaining stocks of old .30-06 caliber M1906 150 gr FMJ ammunition left over from WWI; thus the U.S. military threw away an opportunity to adopt the superior performing .276 caliber and the M1 Garand rifle was adopted in the old .30-06 caliber. Following WWII the United States Army again made a colossal weapon system selection error when it rejected the British .270 caliber 130 gr and .280 caliber 140 gr ammunition fired at approximately 2400 f/s and instead insisted on the full power 7.62 x 51 mm cartridge that offered nearly identical ballistic characteristics as the old .30-06 it replaced. Given the 7.62 mm’s extremely short life as the standard service rifle caliber, in hindsight, we can hypothesize that both the .270 (6.8 mm) and .280 (7 mm) would probably have been ideal combat rifle calibers and might still be in use today if either had been chosen. In 1972, the U.S. Army issued a MNS and detailed specifications for a new SAW/LMG. At that time, in reviewing calibers for the new system, 5.56 x 45 mm was felt to lack effective range and terminal performance while 7.62 x 51 mm was felt to be too heavy; weapon developers and joint users felt no current weapons systems and calibers could meet the requirements, thus a new compromise caliber was necessary--this became the 6 x 45 mm SAW. The 6 mm SAW used a 105 gr low drag bullet fired at around 2450 fps. In 1976, the Army ordered that SAW design efforts be redirected, this included stopping development of the 6 mm SAW cartridge (in part for fear of irritating our NATO allies) and focusing efforts on 5.56 mm LMG designs (XM248/(XM235), XM249/(FN Minimi), XM262/(HK21A-1). While 5.56 mm 55 gr M193 (FN SS92) was standard in the 1960’s and 1970’s, attempts to improve 5.56 mm effectiveness included the XM287 68 gr FMJ and the IWK 77 gr FMJ--both used in the Stoner 63 by NSW in Viet Nam; the 54 gr XM777, as well as the SS109 62 gr FMJ developed by FN for their Minimi LMG. As we all know, the end result was the 1980 decision to adopt the 5.56 mm Minimi as the M249 SAW and the SS109 as the 62 gr FMJ M855 “green-tip”. As noted, 5.56 mm NATO 62 gr SS-109/M855 FMJ was designed over 30 years ago as linked machine gun ammunition to be fired from the FN Minimi/M249 SAW while engaging enemy troops wearing light body armor during conventional infantry combat at distances of several hundred meters--while not a perfect solution, M855 does perform adequately in this role. Unfortunately, combat operations since late 2001 have again highlighted terminal performance problems, generally manifested as failures to rapidly incapacitate opponents, during combat engagements when M855 62 gr “Green Tip” FMJ is fired from 5.56 mm rifles and carbines. This is not surprising, since M855 was not originally intended for use in carbines or rifles, especially those with short barrels. In addition, most 5.56 mm bullets are generally less effective when intermediate barriers, such as walls, glass, and vehicles shield opponents--this is a significant consideration in urban combat. The decreased incapacitation potential of 5.56 mm compared with larger rifle calibers is intrinsic to the small caliber varmint hunting roots of the 5.56 mm cartridge; in many states it is illegal to hunt deer size game with 5.56 mm, so why do we expect it to offer ideal terminal performance against aggressive, violent 100-200 lbs human opponents? As an interim solution to these problems, deployed SOF units have used 5.56 mm Mk262. The Black Hills produced Mk262 uses the 77 gr Sierra Match King (SMK) OTM and is built as premium quality ammunition intended for precise long-range semi-auto rifle shots from the Mk12 rifle. It is great for its intended purpose. Mk262 has demonstrated improved accuracy, greater effective range, and more consistent performance at all distances compared to M855 when fired from current M16, Mk12, M4, HK416, and Mk18 rifles and carbines. However, despite this substantially improved performance, Mk262 still manifests the problems of poor intermediate barrier penetration and somewhat variable terminal performance inherent with the SMK design. The disturbing failure of 5.56 mm to consistently offer adequate incapacitation has been known for nearly 15 years. Dr. Fackler’s seminal work at the Letterman Army Institute of Research Wound Ballistic Laboratory during the 1980’s illuminated the yaw and fragmentation mechanism by which 5.56 mm FMJ bullets create wounds in tissue. If 5.56 mm bullets fail to upset (yaw, fragment, or deform) within tissue, the results are relatively insignificant wounds, similar to those produced by .22 LR--this is true for ALL 5.56 mm bullets, including military FMJ , OTM, and AP, as well as JHP and JSP designs used in LE. This failure of 5.56 mm bullets to upset can be caused by reduced impact velocities when hitting targets at longer ranges, as well as by the decreased muzzle velocity when using short barrel carbines. Failure to upset can also occur when bullets pass through minimal tissue, such as a limb or the torso of a thin, small statured individual, as the bullet may exit the body before it has a chance to upset. Finally, bullet design and construction plays a major role in reliable bullet upset. Without consistent bullet upset, wounding effects are decreased, rapid incapacitation is unlikely, and enemy combatants may continue to pose a threat to friendly forces and innocent civilians. Angle-of-Attack (AOA) variations between different projectiles, even within the same lot of ammo, as well as Fleet Yaw variations between different rifles, were recently elucidated by the JSWB-IPT. These yaw issues were most noticeable at close ranges and were more prevalent with certain calibers and bullet styles—the most susceptible being 5.56 mm FMJ ammunition like M855 and M193. What this means is that two shooters firing the same lot of M855 from their M4’s with identical shot placement can have dramatically different terminal performance results: one shooter states that his M855 is working great and is effective at dropping bad guys, while the other complains his opponents are not being incapacitated because M855 is zipping right through the targets without upsetting. Both shooters are telling the truth… 2.5 degree AOA @ impact 12” 0.5 degree AOA @ impact 12” As articulated by combat AAR’s the last few years and demonstrated in recent military wound ballistic testing, improved combat ammunition that is specifically designed for rifle and carbine use, not machine guns, is urgently needed. New loads should offer:  JAG approval  Acceptable accuracy at 300-500m  Full reliability in diverse  Good soft tissue terminal environmental extremes performance (early consistent bullet  A thermally stable propellant upset within 1 or 2 inches of initial  Consistent lot-to-lot and shot-to-shot tissue penetration performance, even when fired from  12-18 inches of penetration coupled short barrel weapons with maximized tissue damage during  Crimped and sealed primer the first 10 to 12 inches of travel in  Sealed case mouth tissue  Cannelure for functional reliability in  Designed to minimize AOA and fleet adverse conditions yaw issues  Decreased muzzle flash  Blind to Barriers It is critical that new combat ammunition be “Blind to Barriers” and not suffer from terminal performance degradation from intermediate barriers--especially automobile windshields & doors, and common structural walls. Ammunition should be light and compact enough for the operator to carry an adequate supply in magazines of at least a 25 round capacity. The rifle should be similar in size, weight, and ergonomics to the proven M4/M16 weapons. Recoil should be manageable to allow full auto fire when necessary, along with the more usual rapid, aimed semi-automatic fire. Important Gel Block Measurements to Assess Terminal Effectiveness The shot into bare gelatin depicted below illustrates ideal terminal performance. “Barrier Blind” ammunition should demonstrate minimal changes in terminal performance between unobstructed shots into bare gelatin and those obstructed by intermediate barriers. Pen = 12.1” NL = 0.8” TC = 4.5” max diam @ 4.2” depth TC length from 0.8” to 8.1” of pen 11.. IInniittiiaall UUppsseett DDeepptthh ((NNeecckk LLeennggtthh)) ---- OOppttiimmaallllyy 11”” oorr lleessss,, uupp ttoo 33”” 22.. TTeemmpp CCaavviittyy LLeennggtthh ---- AAss lloonngg aass ppoossssiibbllee iinn tthhee ffiirrsstt 1122”” ooff ppeenneettrraattiioonn 33.. TTeemmpp CCaavviittyy HHeeiigghhtt && WWiiddtthh ---- BBiiggggeerr iiss bbeetttteerr iinn ffiirrsstt 1122”” ooff ppeenneettrraattiioonn 44.. DDeepptthh ttoo MMaaxx TTeemmpp CCaavviittyy DDiiaammeetteerr ---- TTyyppiiccaallllyy aatt 44”” ttoo 66”” ooff ppeenn 55.. TToottaall DDeepptthh ooff PPeenneettrraattiioonn ---- LLeessss tthhaann 1122”” && mmoorree tthhaann 1188”” iiss nnoott iiddeeaall Note: The ideal shot depicted above is a 6.8 mm Hornady 115 gr OTM impacting at 2600 fps