So we are assembling a PSA rifle for the father in law for xmas this year. We ordered one of their black Friday deals and ordered their 9310 bcg to go with it. I put the bcg in the upper and I noticed their is a gap, that is not present on any AR rifle I've ever seen. curious if yall have seen this? It seems to all function, though I haven't fired it. It was pretty stiff at first, though it's smoothed out a good bit the more I manually cycle the bolt. So, am I missing something here? Is this something yall have seen? Just want to make sure he's not getting something defective . thanks!