04-25-2017, 11:02 AM
All good points here. I'm a shooting match competitor and not a hunter, and always loved the 243 Win due to light recoil and great long range ballistics. My 243 load (out of bolt gun) was a Sierra 107 at 2870 fps. I own a DPMS LR-243 (accurate gun), but I always wanted to have 243 Win ballistics out of a nice & handy small frame AR. To that end I recently built a 6mm Grendel upper and bought a 6mm Fat Rat upper and plan to test them side by side; I don't think they'll replicate my 243 Win ballistics but I'll be happy if I get close, especially given I'll only be burning about 30 grains of powder. My 6.5 Grendel load is a 123 bullet at 2529 fps, and it's a great gun, but I'd rather have a 0.5 BC bullet going 2700+ fps.