depends on what kind of slugs. Lee keydrive slugs use a stnadard shot wad. vitt/boos slugs use a custom cushion stlye. hornady and lyman slugs use modified shot wads. BPI use a vareity. it just depends on what slug you want dictating what was you use. buy the BPI slug handbook and it will tell you most of the combos. also the lyman shotshell book is good too.