WHAT DOES BLACKHORN 209 POWDER IN STOCK MEAN?

I have a CVA optima in stainless-steel. I also have the black horn 209 breech plug. I load one hundred grains by volume of Blackhorn 209 with a 250 grain Barnes bullet. I have discovered that you actually ought to use a very good primer. Usually do not make use of the primers built for black powder as this is simply not black powder. I make use of