I shoot a cva optima, federal primers and have only ever used blackhorn 209, pellets are a no no here. This rifle shoots very good and never have had issues, one thing cva recommended was if you shoot blackhorn, get the specific breech plug for that type of loose powder. I know plenty of people on the net say it's not required, but if I have the bull of a lifetime come in, I want to make sure my equipment would not be the source of a fouled up situation. Maybe a different breech plug? I'm not familiar with knight muzzle loaders though