Manufactured by an Aussie company named Metal Storm, this is an 800 gram 12 gauge shotgun that will fit under the M4, M16, etc., et al. It also can be fired alone with a detachable pistol grip. Now everyone gets to carry a room cleaner.
The video is less than impressive, but HERE it is. Cool idea, nonetheless. It's ready for delivery today.
Oh, it's called a MAUL.