I have shot a couple thousand rounds through 2 barrels (AR 15), the gun started as a Grendel (APF)with a 18" barrel and shot well, usually sub moa. I wanted it to be more accurate and ended with a 20" Lilja barrel, it is more accurate, also came at a price. The gun is extremely light and works great for hunting, I shoot 120 Noslers, almost all coyotes have been DRT (couple poorly placed shots). I think it is a great 250 yard hunting gun, since most coyotes do not give time to spin turrets and I am not that good with hold over. It is accurate way beyond that range. As far as brass goes I was getting 6 to 8 loads out of Hornady brass, now running Lapua brass, I expect over 20 out of the Lapua.
I love my Grendel, I would recommend a wildcat built off the Grendel. I mostly hunt now with a 6 DTI, and if I could do it all over again I would have a 243LBC (Grendel brass), just because you can get good brass for a Grendel.
Ruger American, I had 1 of these in .243 it shot good for a few rounds after that it would warm up and the groups would open up, a friend had 1 in .270 that did the same thing. It could be good with a Grendel with the slower speeds, just depends on how many rounds you want to shoot.