What gun and what powder? Are you doing a bullet/sabot or those lowly powerbelts?
My two .50 long guns use 77 grains weighed [110 grains measured by volume] of BH209 powder, .44 cal 300 grain XTP Hornady pistol bullets in green crush rib sabots lit by Winchester 209 shotgun reloading primers [blue box]. Fed 209 and CCI mag 209’s work well too. DON’T use any of those 209 primers sold as muzzleloader specific primers….way too cool of a flame for states bordering Canada during a muzzleloader season.
My .45 inline uses 70 grains weighed of the BH209 powder [100 grains by volume measure] with a .40 cal, 200 grain XTP in a blue sabot lit with the same Winchester primer. This and the two 50 long guns will plant five to ten shots inside a 1″ bull at 100 yards. Uncanny accuracy.
My .50 cal inline pistol gets 63 grains weighed [90 by volume measure] of the BH209 powder, a 240 grain, .44 cal XTP in a plain green sabot lit with the same Winchester primer. This load will do 1″ at 50 yards.