For what it's worth, my DPMS AP-4 Carbine got to be much smoother cycling after 300+ rounds were run through it. (You could see the wear marks and high spots that were worn smooth and shiny on the bolt lugs, bolt cam pin, and the bolt carrier itself after 300 or so rounds). These guns need to be broken in with hot ammo. I don't care what anyone say's they should or shouldn't do out of the box. Start with a few hundred rounds of some cheap, hot 180 grain .308 ammo, then work your way into the lighter stuff. You don't need Federal Gold Medal. That stuff isn't loaded that hot anyway. Get some cheap Remington Core-Lokt 180 Gr. soft points, or some Federal 180 Gr. Power Shock loads. They're loaded hot with slower burning powder. And you can find them on sale for well under $20.00 a box if you shop around. Here is a whole bunch available from Natchez. Winchester Super-X Power Point 180 Gr. $16.99 https://www.natchezss.com/winchester-sup...fps-20-box.html Federal Power Shock 180 Gr. $15.49 https://www.natchezss.com/federal-power-shok-rifle-ammunition-308-win-180-gr-sp-2570-fps-20-box.html PPU 180 Gr. $14.29 https://www.natchezss.com/ppu-rifle-ammunition-308-win-180-gr-sp-2454-fps-20-ct.html All of these will run in your rifle. And after 300 or so rounds of it, followed by a good cleaning and lube, I'm betting most any 147 Gr. FMJ 7.62 X 51 MM load will run as well.