Purpose problem:  About the third round I get a lightweight hammer strike.  I have attempted both of those H2 and H3 buffer weights.  H2 I used to be only getting just one shot, H3 I now get two shots off.  I've attempted this on two uppers, just one carbine and 1 pistol, but utilizing the exact same BCG.  I requested an aimsurplus NiB BCG, I'