Gunpowder


Gunpowder, whether black powder or smokeless powder, is a substance that burns rapidly, releasing gases that act as a propellant in firearms. Both forms of gunpowder are low explosives. As it burns, a subsonic deflagration wave is produced rather than the supersonic detonation wave which high explosives produce. As a result, pressures generated inside a gun are sufficient to propel a bullet, but not sufficient to destroy the barrel. At the same time, this makes gunpowder less suitable for shattering rock or fortifications, applications where "high" explosives (called as brisant in chemistry, e.g. TNT) are preferred.