I've been running the XCR mags, you can get 6.8 Pmags? I really like the trigger on mine, it's a second gen though, I've heard there were problems with the earlier ones. I've also noticed that the 6.8 seems to be kinda load picky, my 5.56 barrel / bolt doesn't seem to have this problem, mind you, I really only use that set up for prairie rats and 3 gun. Also, as previously noted, my crown was a bit rough, ( In discussion with Alex at Robarm, he indicated that a couple got out with bad crowns so....). All in all though this isn't a varmint gun and the accuracy I'm getting now is what I'd expect and then some. I'll stick with the Sierras and Hornadys for hunting with this rig for now and do a bit more research on the other rounds. On another note, 90 gr. Speers are pretty tight shooting with a similar load, but they're varmint bullets, not so good for Whitetails.