So I recently picked up a KWA LM4 and today im having feeding issues such as double feeding, jamming, and bbs being jammed into where the bolt locks with the hop up, I don't have the proper tools or the know how on how to tear down and fix one of these, if anyone could point me to someone who does or has expirence themselves please contact me ASAP
I looked at a guys GBBR a while ago and diagnosed a similar problem.
What ended up happening was that the bottom part of the nozzle(the part that pushes the bb forward out of the mag, had broken off. So insteal of pushing it forward and up the ramp infront of the nozzle, it would push it forward, and get blocked by the top part of the nozzle(the part that the gas goes out) and this crushed the bb just below where it should have fed.
This might not be your issue, but from what you have stated, that is my educated guess. I would look at your nozzle and see if it looks irregular at all. Chances are it may have broken. Solution: new nozzle.