Perform issue:  About the third round I get a light hammer strike.  I have tried using both of those H2 and H3 buffer weights.  H2 I used to be only having 1 shot, H3 I now get two shots off.  I've tried using this on two uppers, just one carbine and just one pistol, but using the exact BCG.  I requested an aimsurplus NiB BCG, I'm going to try