Bolter is right, When i started I kept practicing and practicing to shoot faster and had that sorted. It was only when I started training and doing shooting drills I relised how pointless it was If you can't move and fire accuratly with the first few shots, being able to shoot fast makes no difference
But hey! put a elastic band (or 2 bands) around your index and middle finger. move your fingers away from each other as if you were walking a trigger. keep doing it, I used to do it while watching a movie. that helped me.
But as bolter said, nothing beats just getting out there and practicing some snap shooting and running and gunning - that'll really improve your game.
nothing is better than practice, when i first entered the tournament scene i needed to improve my off hand and i found if watching tv in bed having my setup with me and just going back to it every now and then and getting my fingers as fast as i could then leaving it then trying again to beat what i had previously achieved.