WOW... keep that wife, thats a dandy rifle. Since you have no projectiles, you might want to try the following that can usually be obtained at a Wal Mart.

.45 caliber 300 grain Hornady XTP with a black high pressure Harvester Sabot. Start out with 80 grains of Pyrodex and work in 5 grain steps from there. You should obtain your best load somewhere around 100 grains.

As Triple Se7en said Knight bullets and sabots wil probably give you the best results. They can be ordered through Cabela's in bulk somewhat reasonable. Harvester black High pressure sabots are also good sabots.

Be sure and swab between shots. If your Knight is like my Black Diamond, if I don't swab it is almost impossible to reload some bullets.

Good luck with the rifle