Grendel as a Universal Infantry Cartridge

[bwaites]

Bill,

Did you mean that with a muzzle velocity of 2590 fps, the 123 AMAX is still supersonic at 1000 yds, (at 1223 fps)? Same for the Scenars? Those are some pretty good velocities. Any pressure signs on the brass?

Thanks for the info.

LRRPF52

LRRPF52, yes, if I recall correctly, sea level speed of sound is 1126 FPS under standard atmospheric conditions, so both bullets should still be supersonic at those speeds.

No pressure signs, and both are the factory loads. I pulled ammo out of brand new boxes, shot it through my 28" and then immediately through a 20" my friend owns. The Hornady was from the first batch of Hornady ammo from last year.

I'll have some second run ammo this next week and will chrono it.

ES for the Scenars was 35 FPS, and for the Hornady was 26 FPS. Not bad for factory loads. I also ran some hand loads, with XBR under 107 Sierras, and they were at 2790 FPS with ES of 19. I got close to factory speeds with TAC at 2712 and ES of 21 under AMAX 123's as well. Scenar 123's over N133 ran 2642 but had a much larger ES of 48.

None of the loads did anything unusual, and there were no apparent pressure signs, but I don't put much faith in pressure signs in gas guns. I've seen broken bolts with perfectly normal looking brass in both Grendels and 5.56's.