proto-Sturmgeweirs
automatic (according to some sources - self-loading) carbine of the Swiss Adolf Furrer system chambered for 7.65x35 cartridge, 1921,
the cartridge is made on the basis of a shortened and re-compressed cartridge case of the 7.5x55 GP11 rifle cartridge, the carbine is structurally a direct predecessor of the Furrer Lmg.25 light machine gun . The main difference between a serial light machine gun and an experienced carbine is the cartridge. Like a machine gun, the carbine’s magazine is attached horizontally to the right; the automatic operation is powered by a movable barrel with its short stroke and lever locking.
Furrer Lmg-25 light machine gun with an additional rear support (which could also be mounted under the butt).
Furrer Lmg-25 light machine gun on a special tripod and with an optical sight.
Scheme of operation of the automatic machine gun Furrer Lmg-25. At the top are the moving parts in the forward position, the barrel is locked with a bolt. Below are the moving parts in the maximum rollback position.
| Caliber | 7.5×55 GP11 |
|---|---|
| Weight | 8.65 kg |
| Length | 1163 mm |
| Barrel length | 585 mm |
| Nutrition | box magazine, 30 rounds |
| Rate of fire | 500 rounds per minute |
The Furrer Lmg-25 light machine gun ( Leichtes Maschinengewehr Modell 1925 ) was developed in the first half of the 1920s by Colonel Adolf Furrer, head of the government arsenal Waffenfabrik Bern (W+F) in the Swiss city of Bern. In 1925, this light machine gun was adopted by the Swiss Army, where it was used until the late 1950s - early 1960s, when the Swiss began to receive automatic rifles Stgw.57 chambered for the same cartridge and having characteristics close to those of a light machine gun. This machine gun was practically never exported. Like many other systems of Swiss design and production, the Furrer Lmg-25 light machine gun was distinguished by the highest quality of workmanship and a very high price, as well as excellent reliability, survivability and shooting accuracy.
The Furrer Lmg-25 light machine gun had automatic operation using recoil energy with a short barrel stroke. The bolt was locked by a cranked pair of levers located in a horizontal plane, while, unlike the Maxim or Luger systems, the design included an additional third rod that connected the rear lever of the locking assembly with a fixed receiver. This ensured a constant kinematic connection between the bolt and the movable barrel, while ensuring a higher speed of recoil and retraction of the bolt in relation to the barrel. This scheme theoretically increased the reliability of the automation by using the mass of the barrel throughout the entire cycle of movement of the bolt, but it also greatly complicated the design and placed high demands on the accuracy of the fit of the mechanism parts. The cartridges were fed from box magazines adjacent to the right, and the cartridges were ejected horizontally to the left. The cutout in the left wall of the receiver, in which the locking levers moved, was closed with a special dust-proof cover in the stowed position. The machine gun barrel was air-cooled and allowed quick replacement, but when changing the barrel, the entire bolt block connected to the barrel by locking levers was also replaced. Firing was carried out from an open bolt, while the firing pin was released when the moving parts were rolled out, which ensured a reduction in the peak recoil of the weapon. The machine gun allowed firing in single shots and bursts. The machine gun was standardly equipped with a wooden butt, a pistol grip and a two-legged folding bipod. Additionally, a rear support (attached under the forend or butt) or a special infantry tripod could be used.