I haven’t done load development per se since all 3 of my Grendels are under 100 rounds, but the “bulk” load I put together to form brass and break in barrels is 123 grain “seconds” over 27.8 grains of TAC is only getting me 2250-2270 from a 14.5” at sea level. The Precision Firearms 123 grain Lapua Scenar only did 2270 in my 13.9” Grendel. It’s astounding the effect that altitude plays.
Federal ammo has generated the fastest velocities from the 12”.
90gr TNT does ~2700fps.
120gr OTM does ~2400fps.
Really surprised me. I’d like to have a higher BC 90gr bullet made with a really long secant ogive that can be punted out at those speeds.
You can really tell 100gr ELD-VT is fast and flat from the 12” just through the scope. I always get DOPE from my ballistics program, so I know it will be flat, but it really shows through the optic. Same for 110gr PPU.
The 100-110gr are noticeably-more quiet too through the TBAC Ultra 5 30 cal can.
Of all the 20+ ARs I have, I still hold to the choice that if I had to grab any of them, the 12” Grendel is the easy option for me. Such a fun little gun.