I've been given a mill and lathe as retirement gifts from my Wife. Yeah! I took four semesters of gun smithing and consider myself to be a novice at best. But love every minute. Now we moved and as we meet new people I'm finding those who would like some of the things I can do. I've just been asked to cut down a shotgun barrel and re-thread it. My questions include: Is this legal? To what length can it be cut? If I pin the flash/breach device would it be considered barrel length? What would be the cost one should expect for this kind of service? Thanks for considering me.