Leupold Mark AR scope in Burris 6-screw rings. Receivers and BCG are stock DPMS. Ammo- handloads with 69 gr MatchKings and RL-15 in Win brass headspaced to 4/1000, primer pockets uniformed, trimmed, and sorted to +- 0.5gr. Also tried 77s with Varget in Lake City. I'm getting 3" groups with anything I put in it, either suppressed or with the flash hider. I'm going to try a different scope but I doubt Leupold let a bad one through. Next will be to disassemble it, inspect everything and reassemble. I had a load that shot 1/2 inch with 55gr FMJ through the stock barrel- I'm a little disappointed. Any ideas? Could it be the BCG with 3,000 rounds mated to the new barrel?