1861 - Breech loaded guns in common use. 1861-1865 - American Civil War. Both breech and muzzle loaded guns used. 1862 - The Gatling Gun is invented. 1869 - Center-fire cartridge introduced.

The M134 GAU-17 “Vulcan” cannon is a six-barreled, air cooled, medium machine gun used primarily as a fire suppression weapon in aircraft for the U.S. military. The so-called “Gatling ...