Hi everyone, I just finished an ar build, using an old colt upper for fun. Once I assembled it I found that there is a LOT of play between upper and lower. Not just a little but more like a whole 1/16" or more! After inspecting, i found that the pivot pin hole in the UPPER is oversized. I know that there are things that snug up the fit at the back of the receiver by the take down pin (accuwedge, etc.) but is there anything I can do to tighten up the fit at the pivot pin? Any help would be appreciated. Thanks!