The Cabela's Extended range & Dead Center bullets are indeed made for them by Precision Rifle. They are excellent choices for your Knight. I have had excellent results (Knight USAK) with the 350gr Xtended Range bullets and I just started to work with the Dead Centers.......and I expect good things from them as well.
If you want to see exactly how the Xtendeds work on game, check this site out from my hog hunt this year - it has a good post-mortem picture of how it works on game:
http://community.webshots.com/album/39293886KUEdol
"Every moving thing that liveth, I give unto you as meat" (Gen 9:3)
Trust God..........but keep your powder dry!