The GFM cloche was one of the most common defensive armaments on the Maginot Line. A cloche (bell) was a fixed and non-retractable firing position made of a thick iron casting which shielded its occupant. By comparison, turrets could be rotated and sometimes lowered so that only the top shell was exposed.
GFM is an acronym for Guetteur et Fusil-Mitrailleur, (lookout and rifle-machine-gunner), which describes its purpose as a lookout and firing position for light weapons. Most of the bunkers or blocks in a Maginot Line ouvrage were fitted with several fixed armoured cupolas or cloches. The cupolas were designed to allow the soldiers to perform reconnaissance or repel an attack with an absolute maximum of cover, from inside the bunker. The armament of each cloche varied significantly, but were typically equipped with some combination of:
- Light machine guns or automatic rifles
- Vision blocks
- Mounted binoculars
- A periscope (located on the top of the bell)
- A 50 mm. mortar
The cloche consisted of two sections of cast iron: a lining or base that sat over a corresponding circular shaft in the concrete combat block, and the cloche itself, for the 1929 model 2.7 metres (8.9 ft) tall and 1.6 metres (5.2 ft) in outside diameter, projecting about 0.52 metres (1.7 ft) above a concrete apron. The apron sloped away from the cloche for drainage and to allow a depressed field of fire. The interior contained a platform arranged so that one occupant could fire from one of several openings in the 20-centimetre (7.9 in) thick bell. Firing openings were rectangular, and were fitted with a variety of shutters or firing ports, typically stepped to deflect shots away from the opening. A hose could be attached to the weapon to remove gun fumes. Ear-like lifting points projected to each side of the exposed portion of the cloche.
There were two principal types of GFM cloche, each with a set of subtypes. The 1929 Type A cloche was the initial model, with a short variant, a longer version, a wider version, and a model that could accommodate two soldiers. The 1934 Type B cloche was larger in diameter, with thicker armor. The gun ports were redesigned to fire through a ball fitting that was more resistant to opposing fire. Some Type A cloches were fitted with the new ports. Ingame it is the Type A.
After the end of First World War, the French army sought to replace the problematic Chauchat. French commanders considered standardizing on the American Browning Automatic Rifle, but eventually required the development of a locally built weapon. Manufacture d'Armes de St. Etienne, one of several government-owned arms factories in France, proposed a direct derivative of the BAR, but the Manufacture d'Armes de Châtellerault won the bid with its weapon, which was partly based on the BAR action. It had been formulated and designed by a Lt Col Reibel.
The FM mle 24 entered limited production and operational use, but numerous problems with the new 7.5mm ammunition type appeared. In particular, 8mm Mauser ammunition which was in use with captured rifles used by auxiliaries in Morocco during the Rif War, could be chambered and fired with disastrous results. This situation led to the development of a slightly shorter 7.5x54mm type, which was retained in 1929 as the standard calibre for all future rifles and light machine guns in French service. The accordingly modified fusil-mitrailleur modèle 1924 modifié 1929 (FM 24/29) was eventually mass-manufactured (187,000), beginning in 1930, until the older Chauchat could be entirely phased out of service.
The new fusil-mitrailleur modèle 1924 featured a bipod, an in-line stock, a pistol grip, a top-mounted 25-round magazine and a bolt hold-open after the magazine's last round had been fired. Protection of all the openings against mud and dust was excellent. The cyclic rate was 450 rounds per minute. In general,this new weapon was accurate and highly reliable but the barrel was fixed , as in the Browning Automatic Rifle (BAR), and could not be quickly changed as in the British Bren gun.
The FM 24/29 was the standard squad-level automatic weapon of the French infantry and cavalry at the start of World War II. After the French surrender in World War II, the Germans captured large quantities of this weapon, which they used operationally until the end of the war.
From 1943 on, as the French army was re-equipped and re-organized in North Africa with Allied support, the FM 24/29 was kept in service, as French troops considered it superior to the Browning Automatic Rifle.
The gun was used in the GFM Clouche. The GFM Clouche was used by the French on France vs Germany maps. After been captured by the Germans, the Germans used the turrets on fortification lines like Alpenfestung and also for defend on imortant places like the Ratte factory at Sand Storm.