Well "Big Bob" you should probably read all the posts in a thread before making a comment like this.STOP! Break down and have a gunsmith look at it. IF the threads are still good, fine, have him install the CORRECT nipple. If the threads are no longer any good, there are OVERSIZE threaded nipples that can be installed. If that is not possible, DO NOT use a threaded insert as it will wind up in your face! At that point get a new breach plug and nipple installed, and don't try to do it yourself, or get another barrel.