Today while sighting my LMT defender upper in, I never got better than a 4" grouping at 50 yards. The barrel is in great shape. I'm thinking it is either ammo or my sights. I was shooting LC M193 55gr. The sights on it are magpul's gen 2 BUIS.
Is 4" typically expected at such a short distance? I plan to try other types of ammo as well (heavier than 55gr) All previous ARs I had were 1x9 (rifling)and this one is 1x7.

