The Gatling gun's operation centers on a cyclic multi-barrel design which allows for better barrel cooling and a synchronized firing and reloading sequence. Each barrel fires a single shot when it reaches a certain point in the cycle, after which it ejects the spent cartridge and loads a new round, cooling down in the process. This configuration gives the Gatling a higher rate of fire than earlier rapid-fire prototypes and circumvents barrel overheating. However, the Gatling gun is not a true automatic weapon despite its continuous fire, as it requires an operator continuously turning a crank in order to function compared to real machine guns which recycle a portion of the exhaust gases in the chamber to reciprocate another round for firing. Gatling sold his patent's to Colt Firearms in 1870 and the company began marketing carriage mounted guns from the US Civil War onward. Towards the 20th century after the German's invented the Maxim Gun in 1884 and American gun designer John Browning invented the 1895 machine gun, the gatling gun was deemed obsolete.
In Rurouni Kenshin, the Gatling gun first appears in the possession of Takeda Kanryū. Upon revealing the weapon in his mansion to Himura Kenshin, Shinomori Aoshi and Myōjin Yahiko, Kanryū boasts that the Gatling he has purchased is a new model unknown even to the Meiji Government and capable of firing two hundred rounds per minute. Kanryū first attacks Aoshi, shooting the onmitsu's legs while Kenshin and Yahiko flee, but the noise of the weapon draws all of the Oniwabanshū to the scene, where each of Aoshi's four subordinates give their lives in turn to rescue their Okashira and give Kenshin an opportunity to strike. In the manga, Kanryū's undoing is his own unfamiliarity with the weapon and combat in general; after firing two hundred shots per minute for some time, the Gatling runs out of ammunition. However, in the anime, Kanryū remembers to reload the gun periodically and his undoing comes at the hand of Beshimi, who manages to fire one of his Rasenpyō into the Gatling's ammunition feeding mechanism, jamming it at the cost of his own life.
In Rurouni Kenshin - Restoration, Kanryū appears with a stylized and modified Gatling gun which detached from its transportation carriage and is apparently light enough for the corrupt merchant to carry around and use in his arms. He uses this weapon to slaughter swordsmen in the basement of his mansion for fun, but is defeated by Himura Kenshin, who demolishes the weapon with a single strike.
- While the Gatling gun was the fore bearer to the modern machine gun and was deemed obsolete with the advent of the modern machine gun in 1884, the gatling gun resurfaced in the Mid 20th century as an externally powered cannon.
- In the English Dub, it is implied by Kenshin's reaction that even he fears the gatling gun, presumably he witnessed the weapon being used against samurai during the Boshin War.