The invention of the machine gun by Richard J. Gatling (1818-1903) irreversibly changed the face of battle. Gatling took advantage of the newly invented brass cartridge (which, unlike the earlier paper cartridges, had its own percussion cap) to produce the first rapid- fire weapon in about 1862. The Gatling gun consisted often parallel barrels that could fire and reload brass cartridges at rapid speeds through the rotation of a hand-operated crank. With each rotation the firing and loading mechanism of each barrel came into contact with a series of cams. The first cam opened the bolt on the barrel, allowing the bullet to fall into a chamber, while another closed the bolt. A further cam released the firing pin with the final one opening the bolt and ejecting the spent case. The first successful model was deployed in a limited capacity during the American Civil War by Union troops.
The American inventor Hiram Stevens Maxim utilized the power of the cartridge explosion to design the first automatic machine gun in 1884. By Using the recoil power of the fired bullet, the empty cartridge is expelled and the barrel reloaded. Both reliable and easily transportable, with a firing capacity of 600 rounds per minute, the Maxim was adopted by European armies.
Machine guns based on Maxim's design dominated fighting during World War I. In the static environment of trench warfare, the weapon caused heavy loss of life, earning the machine gun a fearsome reputation. It continued to produce deadly results in World War II, but found its popularity supplanted by the lighter and more mobile sub-machine gun.
