You've gotta have a gas issue. The chamber may be rough, and the headspace is worth checking, but it sounds like you're not getting gas. Re-check that the gas block is on correct, check the gas tube at the block, take a photo looking into the open upper showing how far your tube extends into the upper receiver.
Did you assemble the upper, what parts make up the whole system? Barrel, gas block, tube...etc. the more details you share, the more likely one of the gurus will immediately spot the issue.