Geenswampthing
I wish it were that simple, believe me its not. There is a wide tolerance on muzzle loader barrels. Most TC barrels are relatively tight[.500 to .497] Some are so tight that they can only load the thinner sabots like the Crush Rib or Easy load others are much looser like my Endeavor[.501] so it depends.
I will assume that you are right in the normal range for the Omega and suggest that you start with a Short Black Harvester and Shock Wave ot SST 250 gr bullets or some 240gr or 250 gr XTP til you have some thing to judge by the gold Dot 250 is a good reasonable priced bullet that is excellent for hunting but shoots best with a longer sabot in most guns. Lee