What make of Glock is it? And is it a co2 or standard gas? If it's gas are you filling the mag upside down held vertically and charging it for a good 10 seconds is there any sign of gas leaking? Once you have gased it is there resistance on the release valve at the back of the mag. Also do you know which mag came with the gun(is it the one that works) and are they definitely the same brand as the gun.