How about when you return rounds to the magazine they do additional precision damage? Every time you returned the rounds to the mag it would do more and more damage. In pvp this would not be enough to two burst a person, but you would be able to two burst the second person if you were able to continuously return your rounds without missing a precision hit. If you didn't hit a precision hit in 5 seconds the damage would reset. P.S. Fix the mussle flash effects so we can see when we shoot!
The only thing that needs to get fixed is the muzzle flash, besides that, nothing needs to be changed. If you think that this weapon isn't good enough, it's because it is not for you.