Machine gun

a machine gun is and automatic weapon that is capable of rapid sustained fire. Machine guns should not be confused with autocannons.

A machine gun works by capturing a portion of the gas from the round being fired, and using that gas to push the bolt backwards. This chambers another round, which is in turn fired, and the process repeats itself.

The predecessor to the modern machine gun was developed in 1718, by James Puckle, an Englishman. This gun, known as the "Puckle gun", could fire around nine bullets per minute. However, the Puckle gun was a flintlock weapon, and cannot be considered a machine gun in the modern sense of the word.

The first modern machine gun was the Gatling gun, a crank-operated weapon capable of firing over a hundred rounds per minute. It was invented for use in the American Civil War.

The first automatic machine gun was the Maxim gun, invented by Hiram Maxim. The Maxim gun was the first weapon to utilize a gas blowback system; the excess gas of the previously ejected round pushed the bolt back far enough to chamber a new round. The Maxim gun also saw the first use of a coolant system, in the form of a water jacket; the barrel of the gun was surrounded by a "jacket", or sheath filled with water. This greatly increased the sustained fire time of the gun.