Military round comparisons

[SHORT-N-SASSY]

I saw, not long ago, the results of an analysis done of various rifle calibres. I can't provide more details of the circumstances, other than to say it was in a military context. The study (a paper exercise using various ballistic and other performance software available to the military) compared the performance of the 6.5 Grendel (123 grain OTM), 6.8 Rem (115 grain OTM), 7.62mm M80, 5.56mm M855 and 5.56mm MK262. It wasn't intended to be a particularly exhaustive analysis, but I thought you might like the outcome:

In external ballistics, the rounds fell into three groups: the M855 and 6.8mm Rem were very similar; the M80 and MK262 were also very similar, and much better than the first pair; the Grendel was by itself, waaaay out in front on every metric (including calculated barrier penetration). The work included the effects of wind drift as shown on some typical "advancing man" targets at 300m. I didn't note the wind speed, but a shot aimed centre-mass would have hit very close to centre mass with the Grendel, and just clipped the edge of the target with M855.

None of this will come as any surprise to anyone on this forum, of course, but it was nice to see this coming from a military source.

I did point out that replicating these performances with copper+steel bullets as currently favoured by the US Army would be difficult (probably impossible with MK262), due to the considerable extra length required.

I chose the 123-grain OTM projectile for the 6.5 Grendel and the 115-grain OTM projectile for the 6.8 SPC to simulate the results noted by Tony Williams, in his opening Post, above. Had I chosen the 6.5mm 144-grain Lapua FMJBT, with a Ballistic Coefficient of 0.636 and a Muzzle Velocity of 2275 fps, that projectile wouldn't have dropped to 530 ft.lbs., till a little beyond 925 yards!

Moreover, given the deadly serious context of the Thread --- the Military still clings to the same basic cartridge family that this eastern woodchuck hunter abandoned for the 6mm Remington, back in the 1960's --- I dare state that one would be remiss not to emphasize the special attributes of the 6.5 Grendel.