Black Hills 5.56mm 77gr OTM

Black Hills 5.56mm 77gr OTM is the box-quantity version of the load family Black Hills built its reputation on. The company developed the 5.56 precision round for the Navy starting in 1999, and the 77-grain open-tip match projectile that came out of that program is what this cartridge is loaded with. It is aimed at SPR, DMR, competition, and precision AR-15 work where bulk 55gr or 62gr ball is not accurate enough.

Black Hills lists the 77gr OTM at 2,750 fps and 1,293 ft-lbs from a 20-inch test barrel, with a G1 ballistic coefficient of 0.372. That BC is the practical reason to run it: the heavy match bullet holds velocity and resists wind far better than 55gr ball, which is what turns a good 18-inch upper into a rifle that stays useful past 500 yards. It needs a 1:8 or faster twist to stabilize.

The MK262 Mod 1-C is the separate mil-pack product, and Black Hills sells it only as a 460-round ammo can with the military lot-acceptance accuracy test attached. If you want the issued configuration in the issued packaging, that is the one to buy. For zeroing a precision AR, confirming dope, or stocking a DMR load after function testing, this 50-round box is the sane unit.