I would think if the gun shop dealer were to sell you gun powder the first question he would ask is what kind, as there are many gun powders available for re-loaders of the unmentionable weapons and each have their own attributes and uses, there are ball, stick, flake configurations some are grey in color some are black, but this does not make them what one would call black powder. As posted all the black powder that I have purchased over many years say right on the can BLACK POWDER and the grade 2f,3f and so on. Now if I was to walk into a gun shop and ask for gun powder and the merchant just handed me a bottle or can of something I would just walk out. I will throw a curve in here with powders such a cordite and gun cotton through the years there has been much experimentation with different propellant's for weapons but this does not make it a safe thing for muzzle loaders, if does not say BLACK POWDER and the grade and if you are not sure of it stay away from it and find someone who has better knowledge of such things.