"I bought the gun that came with the GHK M4 Gas Magazine. When I loaded the Mag, the bbs got jammed every time it got loaded. I told my self, well that's probably a faulty mag that came from manufacture. So I went and bought a second one. Same magazine. Spent $71 with shipping. Major damage to my wallet and budget. When it finally arrived, I loaded it up and it also got jammed, at the same spot where the first mag got jammed. It's not coincidence!!! These mags SUCKS. They Get jammed and I'm not wasting $71 for another "faulty" magazine.!!!!! DO NOT BUY"