The Negev is an Israeli 5.56 mm light machine gun, developed by Israel Military Industries Ltd. (IMI) of Ramat HaSharon (now Israel Weapon Industries), as a replacement for the 5.56 mm Galil ARM light machine gun, whose barrel would overheat easily during sustained fire. Design work on this new indigenous firearm began in 1985, and it was officially adopted by the Israeli Defense Forces (IDF) in 1997.
The Negev is a gas-operated automatic firearm that uses propellant gases from the barrel to cycle a short-stroke gas piston operating system under the barrel and a rotary bolt locking mechanism. The bolt itself features 4 radial locking lugs that engage the barrel extension and its rotation is controlled by a pin on the bolt body, which rides inside a camming guide machined into the bolt carrier. The bolt contains a spring-powered casing extractor unit, while a lever ejector is housed inside the receiver (it is rotated by the recoiling bolt carrier).
The Negev’s adjustable gas regulator has three settings: “1” – used exclusively when feeding from a magazine (the weapon’s rate of fire in this mode is 850–1,150 rounds/min), setting “2” is used in normal operating conditions when feeding from a belt (rate of fire: 850–1,150 rounds/min) and setting “3” which is used under adverse operating conditions, such as in the presence of dust, dirt or heavy fouling (cyclic rate of fire is 950-1,150 rounds/min). Early prototypes used a different 3-position gas adjustment system: setting “1” – normal operation, setting “2” – for adverse environmental conditions and setting “3” – isolates the gas system, used to launch rifle grenades with the use of a grenade-launching blank cartridge drawn from a special 12-round magazine (from the Galil rifle).