haha, I get it... 870 x 2 = 1740
Legality wise, I cant see it being any different than a 2 or 4 shot derringer...
The NFA machine gun "multiple shots per trigger pull" definition comes to mind, but I don't think that it applies in this case...
Now go away or I will taunt you a second time...
And it's Killer Angel... as in the book