There has been some unsubstantiated posting about Black Hills MK 262 MOD 1 ammunition's lack of accuracy. Black Hills developed MK 262 MOD 1 5.56MM LR AA53 type ammunition by weaponizing and refining a highly accurate 5.56mm 77gr. SMK based MATCH loading. It is the most accurate weaponized factory 5.56mm cartridge I have fired to date and has held its own against non-weaponized 5.56mm MATCH loadings I have tested for accuracy. Below are groups fired with Black Hills 5.56MM 77 GR. MATCH HP (MK 262 MOD 1) SECONDS (lot BLH06J123-01) shown side-by-side with groups fired with 5.56MM Hornady 75gr. TAP T2 (lot 3070360) for comparison. There is a very good reason why Black Hills MK 262 MOD 1 SECONDS & similar 77gr. SMK ammunition is in such great demand: consistent accuracy.


18" 1x7.7 Krieger/CLE heavy barrel: Black Hills 5.56mm 77gr. MK 262 MOD 1 SECONDS (L) vs. 75gr. TAP T2 (R). Both 100yd. groups fired by same shooter/same rifle/same day/same condition with Leupold BR-24X scope.

 

4.14" 500yd. MK 262 MOD 1 SECONDS group (L) fired with 18" 1x7.7 Krieger/CLE heavy barrel in marginal conditions due to summertime-in-the-south's variable winds and boiling mirage:




20" 1x7 Colt Govt: Black Hills 5.56mm 77gr. MK 262 MOD 1 SECONDS (L) vs 75gr TAP T2 (R). Both 100yd. were groups fired by same shooter/same rifle/same day/same condition with Leupold 4.5x14x50 AO scope.

 

MK 262 MOD 0/1 Ballistics Card for SPR 18":



MK 262 MOD 1 chronograph data in FPS 15' from muzzle at Sea Level/59 degrees F:

Colt 10: 1x7 chrome: 2351
Colt 16" 1x7  chrome: 2632  
Krieger/CLE 18" 1x7.7 SS: 2825  (Krieger 5.56mm barrels have a very tight bore giving higher MV than a mil-spec chrome lined barrel of same length)
Colt  20" 1x7  chrome 2785
Bushmaster 24" 1x9 non-chrome: 2902