Belt-fed 12 gauge "LMSG" upper receiver for AR-15

What would you call this thing other than an light machine-shot-gun? (Make sure you swap the barrels out to keep anyone without a sense of humor happy).

Like any “because you can” weapon, the belt-fed 12 gauge is a special kind of crazy, the kind you want in your collection. This custom upper receiver can be attached to an AR-15, but you won’t find it in stores anytime soon.

While there are a few malfunctions, the “jam” appears to be spent casings failing to clear the bolt. Fix the jamming issue and you have the greatest home defense weapon ever.

See it in action with the video below.