there was a "bevel brothers" column in an older Muzzleblasts about "pure lead" vs "harder lead alloy"....seems there was NO difference in loading/shooting pure lead vs wheel weight lead...I realize that different alloys will shrink,etc and the age old saw is "only pure lead in a muzzleloader" I've never bought into that myth myself....as others have said, try it!! I've shot ww lead out of a muzzleloading RIFLE with no noticeable difference in loading,shooting,cleaning,accuracy,etc....