During the 1993 Battle of the Black Sea, a.k.a. the “Blackhawk Down”incident in Mogadishu, Somalia, elite U.S. Army Rangers, Army Delta Force and Navy SEAL personnel were using 62-grain “green-tip” M855 ammunition in their issue AR-pattern rifles, carbines and SBRs. Prior to that time, there had been scuttlebutt that the M855/SS109 62-grain round was an inconsistent performer in the field, but in Somalia, those issues came to a head. Our opponents in the battles there, Somali militiamen (nicknamed “Skinnies”) loyal to local warlord Mohamed Farrah Adid – were seen to absorb multiple center-mass hits from M855 and yet remind in the fight. Since the men reporting these problems weren’t run-of-the-mill line troops, but some of the finest warriors our nation could produce, their complaints were taken seriously and could not brushed-off as a lack of training or something similar. Throughout the remainder of the decade, studies were commenced to examine the problem. A number of findings were relevant. First, the .224-caliber projectiles used in the M4/M16 family of weapons are highly-dependent not only upon muzzle velocity to work, but sufficient yaw-induced instability upon encountering a target, to cause tumbling and subsequent fragmentation inside the target. Indeed, this is precisely how Eugene Stoner and his original design team had intended the original 55-grain ammunition for the AR15 to function; its lightweight high-velocity projectile was designed to fragment upon encountering a human target, thereby creating multiple wound channels within the target. However, with the advent of SS109/M855 62-grain “green-tip,” which had been adopted in 1980 as the new NATO standard cartridge, the design specification called for the new and slightly heavier projectile to be capable of penetrating a standard Warsaw Pact sheet-metal helmet at 500 meters, so the new projectile contained a steel cup or “penetrator” to add mass to the bullet and also enhance its penetrative ability at distance. Not a true armor-piercing round, the new projectile was termed an “enhanced penetrator” round and given a green-tip. Hence, within the FA community, it became known as “green-tip” ammunition. In order to stabilize the new projectiles found in the SS109/M855 family of cartridges, including 64-grain M856 “orange tip” tracer, it was necessary to adopt barrels with a 1:7 twist rate. The faster twist rate and enhanced penetration of the M855 round, it was discovered, tended to cause “ice-picking” or so-called “through-and-through” wounds upon certain body types under certain conditions. At close range, high-velocity M855 tended to over-penetrate the slender-framed Somalis rather than fragmenting. If the target was not so wounded in a vital organ or the central nervous system, he could often remain combat-effective and remain in the fight. This is what the Rangers, Delta and the SEALs had seen at Mogadishu. The small arms establishment within the armed forces therefore sought a solution to these problems in the form of ammunition which would perform better on such missions, and out of the standard M4/M16 family of weapons then predominantly in use. Around the same time, special operations forces within Joint Special… Read more »

This. I always scratch my head at the lethality discussions surrounding mil-spec ammo. Why tie your hands with stuff that’s tied to ancient, misguided rules? I’m a big fan of the Barnes projectiles. No experience with 2-legged critters but they punch above their weight class on medium game so I would expect similar performance in a fight.

Nosler 60 gr. Partition bullet in .223 if you are serious with your hunting.

@GB – I sort of understand the whole Geneva Convention thing. Mainly, I was questioning civilians limiting themselves to rounds that conform. I give the MK262 and similar rounds a pass because they’re more about accuracy…but if I ever find myself dipping into the 193 and 855 stash for a fight, I’ve already done a helll of a lot of shooting.

@ Silence DoGood

Re: “There’s not a single damn word about bullets in the Geneva Conventions.”

OK, what about the Hague Conventions? Mil.gov follows the proscription (prohibition) of said types of bullets, and has since forever, so it had to come from somewhere. Any JAG officers or lawyers in the house?