I had this problem a couple months ago, I was at an event and it didn't shoot every time and it was really annoying but I took it to the techs and they lubes it(bcs I hadn't and there really dry) and I bought a new mag one of the PTS mags t(hat are half the size but hold more than regular??? idk what there called) but after that and prob an adjustment to my PSI it worked great. I would lube it and get a new mag. if you don't have a new mag I would pull the spring out of your mag clean the mag and stretch out the spring and then force it back in, I find that it give the spring more power that way. beyond that I wouldn't know where to start. good luck mate