Hey guys, I'm trying to help my friend out here because he got a kwa usp compact, and whenever he shoots it the slide will always lock back like he's out of ammo in the middle of the mag. It has always been like this since he got the gun, and he's done all the normal stuff like cleaning and lubing it as well as checking the whole gun for stuff that could have got in the gun but it still does the same thing. His dad can empty the whole mag without any problems, and he said that his son's trigger pulls are too long and that if he pulls the trigger faster that it wouldn't lock up on him. I tried to fire it and to pull the trigger really quick and to release it right away as soon as it fired but it locked up on me several times as well. Could it be possible that not doing really quick trigger pulls could cause the slide to lock back? Because I've never heard of this happening before and I was considering getting the kwa usp, but now I'm having second thoughts. Thanks in advance for your help.