lol, so you want a nasty sounding gun with a silencer?
I've got one on my 416 right now
it dulls the muzzle noise down to a PUM PUM opposed to a snapping sound, however this only applies to the muzzle, you still hear the gear box, if you want a quieter gearbox, swap your gears with Systema Helical gears and an Angel Silent piston head set. If you want loud, get a metal piston head.