Knight guarantees MOA accuracy at 200 yds. In all the fooling around with different bullets, weights, and powder, I have gotten MOA accuracy at 100yds once with a good scope. I'm not the best shot in the world, but I can get 3/8" groups from both my factory Tikkas, so I'm guessing there may be a better powder/ bullet combination that I haven't yet found. BTW, the combination I found most consistent was suggested by someone on the help desk at Knight.
Also, I live in Washington, so I have to use the older style primers that have to be exposed to the elements. I use CCI #11 Magnum primers, and have never had a misfire.
I'm just getting back into muzzleloading, but I used to shoot the No Excuses 50 cal 460 grain bullets and had great results.
I used that Shockey's Gold powder and was able to create clover leafs at 75 yards with a T/C Encore.
I'll have to find my old notes, but I think my max load was around 80 grains by weight.
Oh, and I was using small rifle primers in Precision Rifle Vari-Flame 209 primer adapters.
Since you have to use a cap, I would humbly suggest you go to musket cap ignition.
The temp is the same as the #11 mags, I think, but there is lots more flame.
And don't forget to run a nipple pick through the nipple into your charge before you shoot!