home defense weapon
 

I read an article about this gun about fifteen years ago and was wondering if anyone has heard of it. It is a large calibre hand gun that was manufactured in Florida. The calibre I think was 45-70 The cylinder was spring loaded and you wound it up with a key. It performed like a small Gattlin' gun. It is meant to be shot from the hip

Not at all sure, but sounds like you may be describing the Stryker shotgun. These are now Class III destructive devices. Link for ya:Modern Firearms - Striker Streetsweeper Protecta shotgun

Well, something like you described would be a class 3 item.