I can tell you this. Not too many on here use pellets. They are not as versatile as loose powder. Without getting special breech plugs and using Blackhorn 209 powder I would go with Pyrodex RS and a bullet/sabot combo in the 250 - 300 gr range. My personal starting load is 80 grs of Pyro RS and a 300 gr 44 caliber (.429") Hornady XTP with Harvester Green crush rib sabot. Shoot groups going up in 5 grain increments. You will see your groups begin to shrink then get bigger as your charge increases. That is how you will find your rifle's sweet spot.
As a bow hunter and liking to get within 75 yds. This bullet will be more than enough for a human kill on any deer or elk.