Aero Precision AR10 Short Chamber??

[DrewL33]

I built an Aero .308 and just recently finished it. When I went to zero my scope everything went smoothly, however, I am not super thrilled about the ammunition I used(it may not be the ammunition). I am inquiring if anyone on here has one of AP’s .308 uppers and if they are having this same issue…

THE ISSUE: when I go to manually eject a round, the action is hard to open. On every round I manually ejected, there is a scuff mark all the way around the bullet just above the case. Has anyone had this issue? If not, does anyone know what might be causing it? My guess is it’s a short chamber but I’m not sure why it would be any different than any other.