It's more to do with my upper and lower not mating properly (about 5mm gap) I'm using a fusion engine and a prowin hop in a G&P body
is the FE installed straight ? sometimes if you over tighten the buffer tube screw it will pull the FE out of line
I cannot emphasis enough what I mean by very good. They don't just answer questions to do with the engines, they even answered a question I implied which had nothing to do with polarstar.