I have the same gun. Maxihunters, especially the 275-320grains are o.k. My particular gun really, really likes 250 and 300xtp's with an MMP 12 sabot, 100grains ffg Goex or 80grains pyrodex "P". It also does particularly well with 300grain .458 Hornady HP bullets and an MMP orange sabot. My state has no restrictions on sabot usage so I have not bothered with experimenting with other conicals.