Usually, an automatic rifle is a rifle that continuously fires bullet as long as the trigger is pressed. Cartridge shells are ejected and new cartridges are loaded into the chamber automatically. However, most automatic rifles are designed to give both semi- and fully automatic fire. This is called selective fire. They also rifle bullets from a magazine. These features makes them different from other automatic firearms like the machine gun and submachine gun.
Soldiers in the United States Army who carry the M249 SAW are called automatic riflemen. The weapon is also called an automatic rifle. However, it is a fully automatic firearm. These are normally called squad automatic weapons (SAW) or light machine guns.
An assault rifle is quite similar to an automatic rifle. However, it uses less powerful bullets than the machine gun or battle rifle. This allows the soldier using it to control the recoil of the weapon without using a bipod or something similar. Bullets like these are called "intermediate" bullets. For example, the AK-47 assault rifle often uses a 7.62x39mm bullet. The bullet is the same diameter. However, it is smaller and less powerful compared to the 7.62x54mmR. The 7.62x54mmR was what was being used with rifles when the AK-47 was brought in to service.
The very first automatic rifle was the Mexican Mondragón rifle. It was designed by General Manuel Mondragón. He began working on the weapon in 1882. He patented it in 1887. In the 20th century, automatic rifles go back to World War I. This is where the Browning Automatic Rifle (B.A.R.) and Huot were first used. They were supposed to be used like light machine guns to help soldiers attack. However, only the Mondragón rifle and the B.A.R. were used in World War I.
- Hogg, Ian V., and Weeks, John. Military Small Arms of the 20th Century (London: Arms and Armour Press, 1977), p.180, "US Automatic Rifle, Caliber .30in M1918-M1922 (Brownings)".
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