First let me preface with what I’m about to say by pointing out that my state doesn’t have many rules about muzzleloaders so check your regulations first. IE some states don’t allow sabots, don’t allow 209 primers, ect
First I would ditch the pellets and just use the BH209 in your Knight. Pellets seem like a convenient product but if you shoot enough you’ll find that they aren’t very consistent, loose power over time and the cost per shot is much higher than loose powder. Anymore BH209 is pretty much all I use. Powder charges are by volume, if you look closely at a grain you will see that it is a hollow tube, because of this it’s weight is lower than measured volume. When I’m preloading charges I’ll pour several by volume, weigh them, then use that weight to measure more.
For transport of premeasured BH209 loads find some 5cc plastic sample tubes that the medical industry uses for fluid samples. They’ll hold around 100 grains and you can usually find assortments with different colored caps that make packing different size loads for range trips easy to identify.
Knight makes a pretty good bolt gun, I have a 1:20 twist 45 Mountaineer. Some of them come with the headspace a little loose. If you start getting some blowback into the bolt face there are shims you can press into the breech plug to get a few thousandths crush on the primer. This is assuming you have the bare 209 ignition system and not the red plastic jacket style.
In my 50 that I use for hunting Missouri white tail I use 100 grains of BH209, w209 primer and a 250 grain .452 XTP in a black MMP sabot. It’s a cheap load and is an absolute hammer on deer. Depending on what you’re hunting you may want a heavier bullet.