I don't recall what the exact details of the game commission laws are on this, but I was wondering if a smoothbore flintlock could be legally used as a shotgun during the regular seasons? Particularly thinking turkey, small game, and waterfowl. Actually, nix the waterfowl, as I don't think steel shot woudl treat it well.
The flintlock would likely be a modern replica of the Brown Bess musket (made with modern materials and manufacturing for superior safety) and the purpose of hunting with it would be for challenge and heritage.