Some kind of highly modified barret?
That would be a bitch to fire with the trigger almost directly under the cheek rest. Although, im more of a relaxed shooter, so maybe you could still use that practically. It's just begging for a mono-pod at the back =P

Are you going to texture it? Then maybe animate a tori firing and loading =)

Looks BA man =)

@FL: looks pretty cool, but i can has normal maps?

@Nasuke: The handle is pissing me off, its too short, and its weirdly shapped >=(
Also, it would look way cooler with textuered blade, with normal+spectral maps.