My understanging is that the weak link rests with attachment of the barrels to the receiver. Rember, your going to generate a lot more recoil with say a .338 than a 20 gauge. Whether the locking mechanism for a standered shotgun would work I don't know, but its where I would look for trouble. Something heavy and reinforced like you find on a Merkel, would make me feel better than say my Parker, but I would still want to talk to someone who knew darn well what they where doing, incluing the metealurgy involved. as a catastrophic frame failure next to my face involving magnum calibers is the kind of fun that isn't. Its a cool idea though.
FQ13