The tolerances are tight. I had to file and grind both my 56 and 56-1 in the gas block and in the slot in the gase tube. Sharp as can be... Steel, baby, yeah!
LCT RPK same issue. Put in a battery when I first assemlbed it and smoke starts pouring out of the upperhandguard. The side of the slot in the gas tube sliced into the wire causing a short. Battery was toast! Same tweaking as my 56 and 56-1 and all is well.
I have both Firefox and Elite stick batteries. The RS 2000mah 9.6v would have been my choice had I known about them 3 years ago.
Call sign: Usurper