I have a PSA AR-10 .308 that I have use for hog hunting and plinking steel. It is not a precision rig and was not bought to be used as one. My problem is I have enough slop and play between the upper and lower than even when my bipod is locked as tight as possible I still have side to side play. I tried installing an Acuwedge but could not get the upper to closed enough to get the take down pin in. Is there any other option our idea for eliminating our at least reducing the shop between the upper and lower?