We g39c problem
 

I have a problem with my friends WE g39c when i shoot it. When i shoot it the first shot fires fine and then they dont shoot anymore the bb's just roll out of the barrel, every shot after the first shot does this

i find the stock hop up rubber on these guns are generally flimsy and lose their rigidity after a 150-rounds or so, especially if the hop-up is negatively dialed the entire way. in other words, i think they're crap. what ends up happening is the hop-up tunnel becomes so loose that the BB's will at times not seat properly in the rubber chamber and just fall out. i've since replaced the stock hop-up rubber with an RA-TECH one - the quality and performance is night and day. i would suggest a replacing the rubber and rebuild the hop-up assembly.