Although an explosive, black powder (i.e. old timey gunpowder) is not a high explosive. It generates more gas than actual concussive force, so it generally only

Although an explosive, black powder (i.e. old timey gunpowder) is not a high explosive. It generates more gas than actual concussive force, so it generally only works well when enclosed in a vessel like the barrel of a musket or a cannon. On its own it isn't actually a very useful explosive. You couldn't use it for mining, unlike dynamite (made from nitroglycerine). You could set fire to a pile of gunpowder and stand nearby, and you'd be fine. This is why you can buy big bags of black powder easily, but you can't buy high explosives without all sorts of licences and permits.