WHAT DOES BLACKHORN 209 POWDER IN STOCK MEAN?

I've a CVA optima in chrome steel. I also have the black horn 209 breech plug. I load 100 grains by volume of Blackhorn 209 which has a 250 grain Barnes bullet. I have found that you actually should really use a fantastic primer. Will not utilize the primers produced for black powder as it's not black powder. I utilize the CCI magnum primers only.