The Negev is an Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

i 5.56 mm

5.56x45mm NATO

5.56×45mm NATO is a rifle cartridge developed in the United States and originally chambered in the M16 rifle. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries. It is derived from, but not identical to, the .223 Remington cartridge...

 light machine gun

Light machine gun

A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...

, developed by Israel Military Industries Ltd. (IMI) of Ramat HaSharon

Ramat Hasharon

Ramat HaSharon is a city located on Israel's central coastal strip in the south of the Sharon region, bordering Tel Aviv to the south and Herzliya and Kibbutz Glil Yam to the north. It is part of the Tel Aviv District, within Gush Dan metropolitan area...

 (now Israel Weapon Industries), as a replacement for the 5.56 mm Galil ARM

IMI Galil

The Galil is a family of Israeli small arms designed by Yisrael Galil and Yaacov Lior in the late 1960s and produced by Israel Military Industries Ltd of Ramat HaSharon...

 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

Gas-operated reloading

Gas-operation is a system of operation used to provide energy to operate autoloading firearms. In gas-operation, a portion of high pressure gas from the cartridge being fired is used to power a mechanism to extract the spent case and chamber a new cartridge. Energy from the gas is harnessed...

 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

Rotating bolt

Rotating bolt is a method of locking originally developed by Ferdinand Ritter von Mannlicher and found in his Steyr-Mannlicher M1895 straight-pull bolt-action rifle designed for and issued to the Austro-Hungarian Army...

 locking mechanism.