The last evolution was to use a small metallic cap filled with a shock sensitive explosive compound that would ignite with a hammer strike. The source of ignition could be a burning slow match (matchlock) placed onto a touch hole, a piece of pyrite (wheellock)/flint (flintlock) striking a steel frizzen, or a shock-sensitive brass or copper percussi

When the pressure builds up high enough to overcome the crimp friction between the projectile and the case, the projectile separates from the case and gets propelled down the gun barrel, imparting high kinetic energy from the propellant gases and accelerating the projectile to its muzzle velocity. The projectile motion driven by the propellant insi