If its a slow twist you may have to use a PRB though some will shoot conicals. if its a 1-48 twist try a 230 gr XTP with 90-100-110 as long as your manuel say you can use that much powder. If they dont want to shoot accurate then try the Maxie ball and the new FPB also the Power Belts with around 80gr and the Sabortooth with 100gr. With a side lock I stick with Pyrodex using RS for PRB and Sabot and P for conicals, you can use other powders but I get occasionalhang fires with 777 it like Blackorn was designed for inlines and works best with 209's. Lee