What you are about to see is a prototype of the beltfed 12 gauge upper receiver in action. This badass gun uses your lower receiver, so if you have a ar15 its a semi auto shotgun.
However, if you have a registered m16 lower or a drop in auto sear it becomes a full auto 12 gauge machine gun.
Either way, this thing is incredible. Check it out:
Would you want to own one of these bad boys? Sound off in the comments below!