I don't know that these will work in your Knight, but they sure work in my Austin & Halleck's and my Rmington... Take a look
My normal loads for elk have been:
(during regular rifle elk season)
50 Caliber inline
100 grains loose T7 FFG
45 cal 300 grain Nosler Partion - Protected Point
Nosler Sabot
(for recreation and target shooting I change the bullet to a Hornady 300 grain XTP Mag hollow point - cheaper shooting)
But Recently I have switched to a 300grain/.458 Nosler partition PP and an MMP orange sabot - I will use that this year.
I too use BButter and Wonder Lube to treat my barrels, have been for several years now - if you clean right and dry correctly - good stuff. I really don't get a lot of fouling - but I do spit patch after each shot when I can. I do use loose T7 because the pellets are so expensive, so I should tell you and ask you to keep in mind that a 100 grains of loose T7 is more powder than two 50 grain T7 pellets.
Seriously though, if that is a NEW rifle I would buy a box conicals and shoot them through the barrel to help condition (smooth it out) it before I really started trying to develope an accurate load and bullet.