The article is a little misleading. Black powder is not used to make bullets (cartridges) for small arms, not used for pistol and rifle ammunition.
Black powder production is inherently risky. It is classified by DOT as an explosive. Smokeless powders are classified as a propellant, this is one reason why it is more expensive to buy, and many sporting goods shops no longer carry it, because of onerous storage requirements. It is not found on the shelf.
But it is used for an igniter in several types of larger caliber weapons and rockets.
Modern substitutes for black powder are far more efficient, for example some grains actually are perforated with channels and holes to allow better combustion.
I always thought black powder was a little less stable, but I’m not a chemist. That’s just what I sort of heard off hand.
Good catch.
Many years ago I had a couple of muzzleloading cannons. Bought a 25 lb keg of black powder (DuPont) at a gun shop. Walked out of the store with it on my shoulder. (They did have to store it in a magazine well away from the store.)