I inherited a .410 break action shotgun that's not safe for modern ammo due to the lockup. The gun itself I will probably pay to have turned into a low pressure rifle (as per outpost's suggestion) so I'll have a .410 barrel. As the barrel itself seems fine, the thought came to me that I could possibly use the barrel to become the barrel of 2 or 3 blackpowder pistols. The barrel would have to be cut into three pieces, then each piece would need to be recrowned, and the base of each threaded and capped. A flash hole would have to be drilled. And a means of attaching the barrel to the new stock would be needful. Also of course, a lock would have to be bought.
The cutting, recrowning and drilling a flash hole all seem like something that would be easily done by me with my drill press and a couple tools. Same for carving out a pistol stock. Hiring somebody to cut threads and cap the barrel seems needful.
Am I missing a piece of what would need to be done? Is there a good reason why this would be a bad idea? Part of the reason I like this idea is that then there would be 4 pieces of family history to inherit and it sounds like a fun project.