I like the 250grn SST, for shooting & hunting. I have a good supply but plan to try the 300grn Hornady XTP handgun bullet, .452 for the 45. You could try something like that, just get your own sabot jackets to hold the 45cal bullet, Harvestor for me. I'm up in the 110-120 grns of B209 in my Knight Disc. You could try a higher charge of the powder you are using.