Military round comparisons

[stanc]

Using the retained Kinetic Energy of the M855 round at 300 meters (328 yards), 530 ft.lbs., as a parameter, let's compare the M855 with the following cartridges, all from 16" barrels:

Cartridge . . .Bullet Wt./B.C. . M.V. (16" bbl.) . 530 ft.lbs. retained Kinetic Energy @:

M855 . . . . . . 62-gr./0.283 . . 2970 fps . . . . . . . 328 yards;
MK262 . . . . . 77-gr./0.362 . . 2650 fps . . . . . . . 400 yards;
M855A1 . . . . 62-gr./0.371 . . 3020 fps . . . . . . . 450 yards;
6.8 SPC . . . . 115-gr./0.317 . .2575 fps . . . . . . . 480 yards;
M80 . . . . . . .147-gr./0.383 . .2460 fps . . . . . . . 655 yards;
6.5 Grendel. .123-gr./0.547 . .2523 fps . . . . . . . 850 yards.

That sure makes 6.5 Grendel look great. Unfortunately, using specs for the Lapua HPBT Match projectile paints an exaggerated picture of Grendel performance with any likely military Ball load. The closest commercially available analog to M80 Ball is the Norma 120gr FMJBT, with a 0.420 BC. Plug those numbers into a ballistics calculator and the result is not nearly as impressive.