Question: The Fusil-mitrailleur Modèle 1924 M29 was the standard light machine gun of the French Army from 1925 until the 1960s, and was in use until 2000-2006 with the National Gendarmerie, a robust and reliable weapon partly derived from the action of which family of United States automatic rifles (machine rifles) and light machine guns used by the United States and numerous other countries during the 20th century?

Context articles: FM 24/29 light machine gun
Machine gun
Light machine gun
ZB vz. 26
6×45mm SAW
Chauchat
M249 light machine gun
M1918 Browning Automatic Rifle
Squad automatic weapon
Kk 62

The Fusil-mitrailleur Modèle 1924 M29 was the standard light machine gun of the French Army from 1925 until the 1960s and was in use until 2000-2006 with the National Gendarmerie.
 It fires the French 7.5×54mm round which is equivalent in ballistics and striking power to the later 7.62×51mm NATO (.308 Winchester) round.
 A robust and reliable weapon partly derived from the M1918 Browning Automatic Rifle (BAR) action, the FM 1924 M29 soldiered on, practically without interruptions, for more than 50 years.
A machine gun is a fully automatic mounted or portable firearm designed to fire bullets in quick succession from an ammunition belt or magazine, typically at a rate of 300 to 1800 rounds per minute.
 Not all fully automatic firearms are machine guns.
 Submachine guns, rifles, assault rifles, shotguns, pistols or cannons may be capable of fully automatic fire, but are not designed for sustained fire.
 As a class of military rapid-fire guns, machine guns are fully automatic weapons designed to be used as support weapons and generally used when attached to a mount or fired from the ground on a bipod or tripod.
 Many (but not all) machine guns also use belt feeding and open bolt operation, features not normally found on rifles.
A light machine gun (LMG) 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.
The ZB vz.
 26 was a Czechoslovak light machine gun developed in the 1920s, which went on to enter service with several countries.
 It saw its major use during World War II, and spawned the related ZB vz.
 27, vz.
 30, and vz.
 33.
 The ZB vz.
 26 influenced many other light machine gun designs including the Bren light machine gun and the Type 96 Light Machine Gun.
 The ZB-26 is famous for its reliability, simple components, quick-change barrel and ease of manufacturing.
The 6×45mm SAW describes an experimental series of rimless bottlenecked intermediate cartridges developed in the 1970s for the U.S. Army.
 The cartridges were produced in a variety of sizes and from a variety of materials.
 The intent was to develop a cartridge that would replace all 5.56×45mm NATO weapons as well as most 7.62×51mm NATO rifles and machine guns in the U.S. military.
 Eventually, the 5.56mm was retained and only the machine gun portion of the SAW (Squad Automatic Weapon) competition was successful.
 That program led to the M249 light machine gun.
The Chauchat, named after Colonel Louis Chauchat, the main contributor to its design, was the standard machine rifle or light machine gun of the French Army during World War I (1914–18).
 Its official designation was "Fusil Mitrailleur Modele 1915 CSRG" (in English: ""Machine Rifle Model 1915 CSRG"").
 Beginning in June 1916, it was placed into regular service with French infantry, where the troops called it the FM Chauchat.
 The Chauchat machine rifle in 8mm Lebel was also extensively used in 1917–18 by the American Expeditionary Forces (A.E.F), where it was officially designated as the "Automatic Rifle, Model 1915 (Chauchat)".
 A total of 262,000 Chauchat machine rifles were manufactured between December 1915 and November 1918, including 244,000 chambered for the 8mm Lebel service cartridge, making it the most widely manufactured automatic weapon of World War I.
 The armies of eight other nations – Belgium, Finland, Greece, Italy, Poland, Romania, Russia, and Serbia – also used the Chauchat machine rifle in fairly large numbers during and after World War I.
The M249 light machine gun (LMG), formerly designated the M249 Squad Automatic Weapon (SAW) and formally written as Light Machine Gun, 5.56 mm, M249, is the American adaptation of the Belgian FN Minimi, a light machine gun manufactured by the Belgian company FN Herstal (FN).
 The M249 is manufactured in the United States by the local subsidiary FN Manufacturing LLC in South Carolina and is widely used in the U.S. Armed Forces.
 The weapon was introduced in 1984 after being judged the most effective of a number of candidate weapons to address the lack of automatic firepower in small units.
 The M249 provides infantry squads with the high rate of fire of a machine gun combined with accuracy and portability approaching that of a rifle.
The Browning Automatic Rifle (BAR) is a family of United States automatic rifles (machine rifles) and light machine guns used by the United States and numerous other countries during the 20th century.
A squad automatic weapon (SAW, also known as section automatic weapon or light support weapon) is a weapon used to give infantry squads or sections a portable source of fully automatic firepower.
 Weapons used in this role are often selective fire rifles, usually fitted with a bipod and heavier barrel to perform as light machine guns. Squad automatic weapons usually fire the same cartridge as the assault rifles or battle rifles carried by other members of the unit.
 This reduces logistical requirements by making it only necessary to supply one type of ammunition to a unit.
 Squad automatic weapons are light enough to be operated by one person, as opposed to heavy machine guns such as the M2 Browning, which fire more powerful cartridges but require a crew to operate at full effectiveness.
The Kk 62 , also known as Kvkk 62 (konekivääri 62 "machine gun 62" or kevyt konekivääri 62 "light machine gun 62") is a Finnish 7.62×39mm light machine gun designed in late 1950s with the first prototype ready for testing in 1960.
 It was officially adopted as the standard infantry support weapon of the Finnish Defence Forces (FDF) in 1962 as the 7.62 "konekivääri" 62; the first weapons were delivered in 1966.
 It remains in service, although a replacement has already entered use, namely the PKM general-purpose machine gun.
 The weapon is known for its unreliability and is highly unpopular among Finnish conscripts.