Guns & Ammo Magazine said:When a six-man Special Operations team looking for Scuds in Iraq in early 2003 ran into a reinforced Iraqi infantry company, the future looked grim for the Americans. Facing overwhelming odds, it was quickly decided that three men armed with sniper rifles would cover a hasty retreat back to the LZ. With these odds death, or worse, seemed certain.
Yet the ensuing firefight did not go as the Iraqis had planned. Rather than being overwhelmed, the three American Snipers instead put down a hail of highly accurate rifle fire. Advancing against this murderous wall, entire sections of Iraqi infantry were simply cut down. Screaming and rattling away with their Kalashnikovs on full auto, they were knocked from their feet with carefully aimed shots. When staggering losses finally broke their spirit, the surviving Iraqis either threw down their weapons or simply ran away. Scattered about lay the bodies of 167 of their comrades. The Iraqi dead lay in mute testimony to the Americans' tenacity and marksmanship skills.
With the criticism of poor terminal performance leveled by many on the 5.56X45mm, you would think those 167 Iraqis were cut down by 7.62X51mm M14s. Such was not the case. They fell to 5.56X45mm MK-12 Mod 0/1 sniper rifles firing 77gr MK-262 Mod 1. Developed to offer increased accuracy, range and improved terminal performance over the standard 62gr M-855 load, the MK-262 Mod 1 has performed quite well in actual combat. This impressive combat record has stimulated a great deal of interest among civilian shooters, so we thought we'd take a look at this load.
When work was undertaken on what was to eventually become the MK-12 series of sniper rifles it was understood from the outset that a better 5.56mm load would be needed. Standard M-855 MP-Ball (Multi Purpose-Ball) was deemed unsuitable due to its accuracy and terminal performance criteria. Manufacturing specifications for this load only require it to shoot into four MOA from 100 to 600 meters. For use at 600+ yards a projectile with a higher ballistic coefficient was desirable to reduce drop and wind drift. The question was how to make the 5.56mm into a viable 600+ yard cartridge.
While competition shooters, or "yellow glasses", are often scorned by the tactical crowd, they laid the ground work in this regard. Loads using 75, 77 and 80gr HPBT match bullets began to dominate service-rifle competition in the late 1990s. One company that was at the forefront of loading extremely accurate and consistent 5.56mm match ammo was Black Hills Ammunition. Its 5.56mm match ammo was so good, from lot to lot, that it had contracts from all the armed forces rifle teams. This was quite a testimony to both Black Hills and its workers. So, Black Hills was contacted about the specific needs and requirements the military had for this new 5.56mm combat load.
Testing was undertaken using a variety of projectiles and powders, with the goal being enhanced accuracy and terminal performance at extended distances. At first a 73gr Berger Open Tip Match bullet was selected, then changed to a 77gr Nosler Open Tip Match bullet. This load with the 77gr Nosler was called the MK-262 Mod 0. This was later changed to a 77gr Sierra MatchKing, and was named the MK-262 Mod 1. Rather than being loaded to commercial .223 Remington pressures, this ammunition was loaded to higher 5.56mm NATO pressures to enhance performance. The resulting load was very similar to match ammunition loaded for the Army Marksmanship Unit for use in competition.
The ML-12's ammunition evolved and was eventually type-classified as MK-262 Mod 0 and Mod 1. The primary difference between the two is the addition of a semi-cannelure to the Mod 1 projectile to prevent bullet setback during feeding.
Both terminal performance and accuracy of this ammunition are markedly improved over M-855 MP-Ball. Each lot is tested for accuracy by firing 10, 10-shot groups at 300 yards. The average group size is between two and two and a half inches. Due to the way the 77gr Sierra MatchKing behaves in soft tissue, this load offers dramatically increased terminal performance compared to the M855; while still being Land Warfare legal. The downside is that penetration is not as good as the M-855 round on harder targets or body armor.
Curious as to how the MK-262 Mod 1 would compare, I arranged to test some out of a MK-12 Mod 0 clone built by Angus Arms. Initial testing was performed from a bench at 100 yards by the rifle's builder, Angus Norcross of Angus Arms. Five-round groups were fired, and velocity was recorded 12 feet from the muzzle with an Oehler 35P chronograph. Five rounds of 62gr M-855 MP-Ball were fired first as a control.
The M-855 grouped into 2.37 inches at an average velocity of 3,044 FPS; unimpressive but within specifications for this load. Switching to Black Hills 77gr MK-262 Mod 1 cut the group size dramatically. Four rounds clustered into less than half an inch, and Norcross put all five into .6 inch. Most impressive was the velocity of this 5.56mm pressure load. The 77gr Sierras were averaging 2,783 fps from the short 18-inch barrel of the MK-12 Mod 0. In comparison a Black Hills .223 Remington-pressure 77gr match load averaged 2,615 FPS from the same rifle.
From the bench we moved to shooting prone from a ridgeline. Conditions were cold, with an ambient temperature of 30 degrees and wind gusts up to 12 mph. A heavy layer of snow covered the ground. After posting targets 300 yards away I proceeded to fire five-shot groups off the bipod.
First up was the M-855, which grouped into a fairly respectable 5.25 inches. Switching to MK-262 Mod 1 cut group size almost in half. This load averaged three inches at this distance. What was most impressive was how controllable and easy to hit with the MK-12 rifle was with this load. Making rapid multiple hits on multiple targets at random distances is simple. The gun simply spits empty cases.
Without a doubt, the MK-262 Mod 1 has proven very effective in actual combat. It's capable of excellent accuracy out to 700+ yards if you can call the wind. Terminal performance is a noticeable step up from M-855. While it was originally intended for use in the MK-12 series sniper rifles, its enhanced terminal performance has led to it being used in M-4 carbines as well. Basically, it's a desirable commodity being used by whatever troops can get their hands on it.
MK-262 Mod 1 Specifications
Manufacturer: Black Hills Ammunition
Caliber: 5.56X45mm NATO
Bullet: 77gr .224" Sierra Match King, Semi-Cannelured
Color Code: None
Casing: Black Hillls 5.56X45mm Match, Sealed for Submerssion, Crimped Primer
Head Stamp: None
Velocity: 2,791 FPS out of an 18" Bbl
Testing Notes: Velocities are an average of 10 rounds recorded 12 feet from the muzzle with an Oehler 35P chronograph at an ambient temperature of 30 degrees fahrenheit at 100 feet above sea level.