Damn, about time to post something here.
So, Nailgun this time. Accelerated with a gauss type system. Battery in the handguard, 25 nails in the rather conventional magazine. The standard V20 can fire only in semi automatic mode, with both long and close range modes of operation. In other words, you can shoot it in semi automatic mode to shoot nails at a distance or simply press the muzzle to a target and shoot it. The "Billgun nailgun" bootleg conversion turns it into a monstrous hybrid of an assault rifle with an industrial tool, capable of shooting in the automatic setting only. Sporting a far more dirty look, homemade stock and a muzzle "device". I should have probably bolted a flashlight on it or something, but that's what it is for now.
Hopefully I'll get onto the belt fed version at some point.