Firing Problems
 

So this is an update of my old pistol thread, but since it is a new problem I decided a new post was in order, sorry if this makes some angry. But before I had the problem of it not shooting at all. Now I have a success rate of 10% or less right now. Anywhere between 2-30 pistol trigger pulls allows a full cycle, but sometimes you can hear gas escaping but the slide does not move.
I have a video on my camera if visual aid is needed.

Please HELP! Need this pistol to work or else my sniping days are on hold.