Modern smokeless powder is NOT an explosive. It is a propellant. Gasoline is an explosive.
Gasoline is a flammable liquid, not an explosive. Also, while used in a cartridge of ammunition, smokeless powder is a propellant, its also considered a flammable solid, and may
actually be treated as a class b explosive if you transport over 100lbs in a commercial shipment, last I heard. So I would be careful with blanket statements about what is, or is not this catagory or that catagory. An item may
be used for something it was not designed for and then the definition of where that item falls would be expanded.