I don't care about having to clean a leadded barrel as a result, I just wanna make sure I won't harm the rifling itslef. If you're wondering why I wanna do it, it's because the sabot slugs that my Slumaster likes are $3/shot (the price came down $1.50/shot over last year's price!). Last year I used irons only but this season I'm gonna put glass on the thing. The rifled slugs will be used just to get close before zeroing it in with the good stuff. Yes I know about boresighting.