Button Welcome to the forum The best advice I can give you is not to use any PSA uppers/lowers/parts. I know that you have a PSA ar15 that runs great,but their AR308 stuff is so out of whack you are stuck using their parts pretty much only. You may know or not know that there is no milspec for ar308's like there is for ar15's....each mfg has different specs for there uppers and lowers and even placement of detents....PSA is bad news...so just a warning on that. The boys here have been having good luck with Aero and Matrix I believe....I would think it boils down to the barrel and chamber...Ive never shot any steel in mine so couldnt tell ya what barrel would be good....for steel I wouldnt put a lotta money in the barrel,but remember ar308's are very tight when new and steel casings would add to the break in process because of the way they expand to chamber... Wash