Large Bore Colt Lightning Carbine Barrel

You are considering a vintage Large Bore Colt Lightning Carbine Barrel — it’s chambered for an unknown caliber — none of the standard calibers fit into this barrel. It has roughly a .470-inch bore. It’s in good shape for its age with light wear from usage, storage, and handling. The barrel’s blued finish is nearly gone and has become mostly rust-patina freckling and bare metal. It measures 20-inches in length and does not come with front or rear sights — nor has it been drilled and tapped for a scope. The bore is dark and pitted with fair rifling.