QUOTE (zack3g @ March 24th 2009 3:39 PM)

NFA regulations cover several types of weapons.
Machine guns
Short barreled rifles
Short barreled shotguns
Destructive Devices
Any Other Weapon
A destructive device is an interesting category. Shotguns like the street sweeper are DD's because they have a bore size over .50 and supposedly have no sporting purpose and were declared a DD.
Destructive device also covers things like mortar tubes, grenade launchers, grenades, various explosives, artillery pieces and the like.
Seems like they could deem anything a DD, like maybe a AR. It is rather vauge.