There is only one problem with this gun.
1. ITS FRIGGEN HEAVY! Its around 31 pounds. This gun was meant for EOD and to be used against military equipment. It's really heavy to use practically in a live firefight.
As for you people screaming, ZOMG OVERPOWERED! No, you're wrong as usual. Snipers are usually mobile. They take a few shots and move to a new location. Otherwise people zero in on their spot. The weight of this gun will prevent that. Just add a reduction to overall speed like the heavy armor does if someone uses this gun. As for the power, sniper rifles tear through the heavy vest anyway. You act as if this is something new. This gun is also obscenely loud, and as far as I know, its impractical to attempt adding a silencer.