Well what do you expect, when you pull the trigger more than once, it will fire more than once. =) Might want to reword your question for people to better understand it and give you a suitable reply, not just a smartass one like mine.
i had the same problem. if you have an upgrade light switch the gun trigger is bouncing and firing multiple times. what i did is i got the tigershark bolt. then increase the eye delay, and the debounce. it works fine for me now.