I have a Knight Disc but it is basically the same rifle with a different ignition system. I found that my rifle for some reason likes very strong charges. We are talking 120 grains of loose powder. I get the best results from 300 grain projectiles down to 200 grain projectiles. The Shockwaves also shoot real well out of the rifle.

Lately I have been shoot a .458 diameter 300 grain Hornady HP which is an excellent design for a bullet IMO. It is not like a XTP. But the hollow point looks reinforced of sorts and it shoots excellent of of my Disc with 120 grains of Goex 2f and a Remington KleenBore Primer.