Any kind of oil with modern sabots causes problems, scrub the bore with dish soap and boiling water or alk. and windshield warsher before you load it with sabots, use the bore butter on patches or conicals to break it in after the bore is polished 777 won't crud ring as bad ;Pyrodex has a softer residue if the crud rings give youproblems some guns seem to have a lot more problem withcrudrings than others. Lee