I still fail to see the point of an automatic shotgun, regardless of how cool the idea is.
Aside from it being very cool and versatile... boy it's one butt-ugly gun.
It's built like a tank, and looks like one. M4 is a tuned Porsche, by comparison. It can shoot 3.5" 00 buck shells (that's 19 .32 caliber pellets) at a very fast rate. For close combat tactics, nothing could be more devastating. Problem is, it wont pierce body armor, so it's has a limited capacity for battle use.