I got jg rebrand AK47 and now I'm having a problem. Here's the problems, 1# not feeding properly on full auto, I do not have high rof and I use high caps. 2# ever I just change to my stock bucking and now it's not shooting properly, first shoot strong then lower and lower then double feeds. It repeats and repeats. Parts Shs air nozzle, stock bucking, hop up, tappa plate and cilender head. Please help.