I had a .58 h & R Huntsman. Good rifling, but 2/3 down the barrel inside was a ring that broke the rifling up. Could this have been from a bullet that was not seated and created a pressure band when fired? I also thought it could been from corrosion from a failure to clean, but the rest of the barrel was okay. Either way I passed the gun on for parts with a caution not to fire it unless a gunsmith said okay.