I have the exact gun you do - sweet huh?! My preferred load is a 250g hornandy sst with a .452 Harvester sabot (cabelas), 90g 777 or 2-50g pyrodex pellets. The harvester sabots load easier than the ones that come with the sst, and the bullet sits in the harvesters without the "bulge" that occurs with the standard sabots. With this load I can get 2.5" groups at 100 yds if I do my part.