light machine gun

weapon

Also known as: SAW, squad automatic weapon

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 23, 2026

Quick Summary

A light machine gun (LMG) is a type of automatic firearm designed to be operated by one or two individuals. These weapons emerged around 1915, offering greater firepower than standard rifles but being more portable than heavier machine guns.

Key characteristics of LMGs include:
* Portability: Weighing as little as 15 pounds (7 kg), they could be carried by a single soldier and fired from a prone position or rifle-style.
* Operation: Most were gas-operated and air-cooled.
* Ammunition Feed: They typically used detachable magazines rather than belts for easier handling and transport.

Examples from World War I and II include the British Lewis gun, the French Chauchat, and the U.S. M1918 Browning Automatic Rifle (BAR). Post-war, the roles of LMGs were often filled by general-purpose machine guns (GPMGs) and squad automatic weapons (SAWs).123

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