Grendel LMG

[stanc]

The data I've found suggests that the service round projo is 148 grains at 2723 fps. The cartridge seems to be capable of more than that, but maybe that's only in modern bolt actions and not military weapons. The Sellier & Bellot 150 grain FMJ goes 2840 fps out of a 28 inch barrel. That's very similar to the 7.62x51 and we know the Grendel comes close to matching those ballistics.

The Hornady .312, 150 grain FMJ only has a BC of .361, their 150 grain boat tail FMJ has a BC of .398, so we have them beat there for lead cores. Steel cores of the same weight would almost certainly have higher BC's because of the length.

http://7.62x54r.net/MosinID/MosinAmmo.htm shows MVs and BCs for various 7.62x54R military and commercial loads in different barrel lengths. Not sure how the BCs were arrived at (Perhaps they used two chronographs?), as some seem ridiculously low, while some others look excessively high.

I have a buddy with a Mosin Nagant I could probably borrow to do tests, but my range only goes to 300 yards.

At what range do we need to demonstrate plate penetration?

I think it'd be good to do it at 100, 200 and 300 yards, if the 7.62 ammo has boat tail bullets, like 150gr Wolf Gold and Prvi http://7.62x54r.net/MosinID/MosinAmmo029.htm

If you use ammo with flat base bullets, like the 148gr Wolf load http://7.62x54r.net/MosinID/MosinAmmo017.htm , perhaps only 100 yards, since it'd lose velocity too rapidly at the longer ranges.

Many years ago, I shot 1/4", 3/8" and 1/2" mild steel plates at 100 yards, using 7.62x51 M80 and 5.56x45 M193. The 7.62x51 punched holes through the 1/2" plate at that distance, so it seems likely that 7.62x54R also would.

Since I don't know what thickness of mild steel 6.5 Grendel and 7.62x54R will penetrate at 200 and 300 yards, if you decide to test at either of those distances, I'd suggest shooting at 3/8" and 1/4" in addition to (or in place of) a 1/2" plate.

If you feel like it, I'd also like to see a CMU (hollow cinder block) shot at 100 yards with both calibers.

Rick, if you're willing and able to do these tests, I'll gladly pay for the mild steel plates, cinder blocks, and ammo.

P.S. Take good, hi-res photos, please.