[elmer fudd]

with a slug barrel, its still considered a shotgun as it is still designed to use plastic shotshells. else, it would be a .729 calibre rifle, which too big. i believe it would have to be registered as a DD.

Not if it's deemed to have sporting purposes. It's not well known, but any shotgun with a bore over .5" can be deemed a destructive device at the government's will. That's what happened with the Striker/Streetsweeper/Jackhammer shotguns. There was never any legislation or EO to outlaw them. The Secretary of the Treasury simply declared that they had no sporting purpose and were henceforth considered destructive devices.

[absolootezer0]

oh yeah.. i forgot about the semi-autos with drum mags.
can't believe i forgot about those. couple guys i knew had to get rid of them as MI doesn't allow DDs.