Conventional firearms fire a cartridge, which simplifies loading and shooting considerably. In the muzzleloader, however, the projectile is loaded along with an easy-to-light, slow-burning black powder or its approved substitute. When the muzzleloader is fired, the propellant is ignited and the expanding gases force the projectile from the gun.
Black powder’s basic makeup has changed very little since it was first used around 1200 A.D. to charge cannons. Made of potassium nitrate (saltpeter), sulfur, and charcoal, black powder or its approved substitute is extremely dangerous if mishandled. Use care when handling, storing, loading, or transporting black powder.
During combustion, about half of the powder is converted to gas and about half remains a solid residue in the bore of the firearm. The residue, known as fouling, will corrode a firearm. Always clean your muzzleloader at the end of the day.