WHAT DOES BLACKHORN 209 POWDER IN STOCK MEAN?

I have a CVA optima in stainless steel. I even have the black horn 209 breech plug. I load 100 grains by volume of Blackhorn 209 that has a 250 grain Barnes bullet. I have discovered that you truly ought to use a great primer. Will not use the primers created for black powder as it's not black powder. I make use of the CCI magnum primers only. In n