Yesterday in 1866, the U.S. Army adopted machine guns for the first time. Or, well, almost machine guns: the Gatling gun, first patented in 1862, wasn't fully mechanical. Someone still had to ...

The Gatling gun is one of the best-known early rapid-fire, spring-loaded, hand-cranked weapons. A clip of bullets feeds a rotating wheel of barrels and at one time fired 200 to 400 rounds per minute.

Locating a Gatling gun isn't simple, and finding one in working condition is even more challenging. The world's inaugural rapid-firing multiple-barrel machine gun, devised by an American doctor in ...