Primer (firearms)
In firearms and artillery, the primer () is the chemical and/or device responsible for initiating the propellant combustion that will propel the projectiles out of the gun barrel. In early black powder guns such as muzzleloaders, the primer was essentially the same chemical as the main propellant (albeit usually in a finer-powdered form), but poured into an external flash pan, where it could be ignited by an ignition source such as a slow match or a flintlock, though some muzzleloaders have primers like cap gun caps.