It takes a bit of work, but it can be done. The plug is clocking in by turning to the right, so what I do is carefully file the breech end of the barrel where the lugs are in alignment with opposing flats. I use small amounts of inletting black on the plug at the lugs. If you number your barrel flats 1 thru 8 you will see that flat 1 is opposite flat 5, flat 3 from 7, flat 2 from 6.....I file across theses flats in a right hand direction until the plug lines up and is tight at the correct index dictated by the sights, and barrel tennons . I also monitor the breech plug face and watch how it intercepts the shoulder at the end of the female threads. If the plug face shows no indication that it is bottoming out on the shoulder then I need to go around the horn, so to speak, and continue on clocking in.