I recently e-mailed Doc White asking if it were possible to purchase a .45 or .50 caliber White barrel - plain, no sights, no ramrod thimble, no breech threads, etc. And if so, what one might cost?
The answer was "$250 White specs inernally.plus S&H DOC". So I assume if the barrel is threaded into the receiver I may be possible to purchase an appropriate replacement for something over $250.