The Gatling gun's operation centered on a cyclic multi-barrel design which facilitated cooling and synchronized the firing-reloading sequence. As the handwheel is cranked, the barrels rotate clockwise and each barrel sequentially loads a single round of cartridge from a top-mounted magazine, fires off the shot when it reaches a set position (usually at 4 o'clock), then ejects the spent casing out of the left side at the bottom, after which the barrel is empty and allowed to cool until rotated back to the top position and gravity-fed another new round. This configuration eliminated the need for a single reciprocating bolt design and allowed higher rates of fire to be achieved without the barrels overheating quickly.