I have an original TN rifle that had the breech cut off about 15 inches. I wanted to restore the rifle to its original barrel length. I wrestled with the process. Finally, I decided to purchase an original barrel with good rifling, correct length, and enough metal across the flats to cut it to match the swamp of the original barrel. I had one of the barrel makers duplicate the original swamp profile. I used the original front, rear sight, breech plug, rounded the flat edges, and aged the barrel to match the original metal. Now I am in process of extending the stock to restore the rifle.
Roger Sells