any of you that own a G17 by WE tech have by now noticed the slide gets stuck. this is because the outer barrel is too tight within the slide, and grinding the outer barrel down helps reduce it sticking during fire. NOTE this helps for when you are SHOOTING not just cocking it.
it also looks hella cool (at least to me)
ALSO the gas chamber purging.
i dont how else to tell you but when you shoot the gun does not have enough power to slide all the way back. this is because something in the gas chamber is not aligned right. best way to fix this is to take the gas chamber completely apart, then rearrange a few things until it all fits back into place. DO NOT do this if you dont have a clue on what you are doing. if you want ill post a video tutorial on how to do this.