Functionality issue:  Around the third round I get a lightweight hammer strike.  I have tried using both H2 and H3 buffer weights.  H2 I had been only obtaining 1 shot, H3 I now get two photographs off.  I have tried this on two uppers, a person carbine and a single pistol, but utilizing the similar BCG.  I ordered an aimsurplus NiB BCG, I'm l