Custom weapon won't Shoot?

[Chefchen]

I tried to create a new weapon, but everytime i try to shoot the gun nothing happens... Well actually from that point on, i cant change weapons and no animation gets played in first person.
the gun is doing everything i want it to do.
It plays all my animations, i can knife with it... But it doesnt shoot :(
Probably someone of you, know what i did wrong.