By Jean Huon
At the end of the 19th century the Swiss Army chose the Schmidt-Rubin 1889: an excellent repeating rifle. Modernized in 1911, then again in 1931, it equipped the Swiss Army until the end of the 1950s.
The adoption of a semiautomatic weapon in the Swiss army had been considered at the beginning of the 20th century. But at the time there was no unanimity of opinion on the subject of a semiautomatic rifle and the project was abandoned. During the 1940s, the military forces again became interested in this type of weapon, and experimented with a version for snipers with a telescopic sight.
In 1921, an assault rifle designed by Adolf Furrer was tested. Resembling the Swiss MP 19 SMG, it shot an intermediate power cartridge (7.5 x 35). In 1937, a Gaetzi prototype was made by SIG to shoot a 7.65 x 38 cartridge. From 1948, an assault rifle program was launched, which was developed around two systems of ammunition: the standard 7.5 x 55 cartridge and an intermediate 7.5 x 38 cartridge. Waffenfabrik Bern and SIG developed many prototypes that included:
- W + F 1948 Bullpup (7.5 x 38),
- W + F 1949. With delayed opening bolt, it looks like the French MAS 48 prototype assault rifle, because it derives from the StG45 M,
- W + F 1951. Inspired by the German FG 42, it is supplied with a left side magazine (7.5 x 38),
- W + F 1952. Similar to the W +F 1951 (7.5 x 38),
- W + F 1954, 1955, 1956, with right or left side magazines (7.5 x 55),
- SIG AK 53, Amsler-Schlumpf system, gas operated (7.5 x 55),
- SIG AM 55. This became the Stgw 57.
The federal council approved the automatic rifle project rifle in 1956. The rifle was then tested against the Belgian FAL, the prototypes of Waffenfabrik Bern and SIG. The SIG gun was approved in 1957 and became the Stgw. 57 (Sturmgewehr = assault rifle). It was developed by R. Amsler, director of SIG and it works like the CETME and G 3, with a StG 45 delayed bolt.
Description
The short stock is moulded rubber and is assembled to the back of the frame using a fitting, attached by a quarter of turn, and locked by a rocker lever located at the bottom. The recoil spring is composed of two concentric helical springs with a guide rod. The square shaped frame is made of cast steel and has an ejection port on the right. The cocking lever, made of aluminium, is located on the same side. The trigger mechanism box is made of stamped steel and is mounted under the frame and locked with a pin. It comprises the trigger, single shot sear, full auto sear and hammer, with their cams, pins and springs. A folding winter trigger is mounted on the right side of the box allowing shooting with gloves and is also used for grenade launching. The pistol grip is of black plastic, it is attached withy a screw under the trigger box. The selector is located on the left side, above the pistol grip. From top to bottom, the positions are: safety (S), single shot (E) or burst (M). The box magazine is curved and contains 24 rounds. It is inserted from the bottom into an opening in front of the trigger assembly. The magazine release is mounted above the trigger guard. The barrel is almost entirely contained in an aluminium jacket, perforated with oval cooling holes. The barrel has four grooves, one turn in 10.4" (270 mm.) and the chamber is fluted. A short plastic fore end is mounted under the rear part of the aluminium jacket cooler. A grenade launching sleeve is fitted to the front of the barrel and ends in a flash-hider. A folding carrying handle is located at the middle of the gun, at the center of gravity. A folding aluminium bipod can be mounted at either end of the jacket. It can be folded forward in the case of a rear mount; or back in case of a front mount. The bipod is marked with numbers used for grenade launching. The bolt is made of the body and the head is provided with locking rollers. The firing pin is actuated by an L shaped hammer relay. The sights can be folded down and consist of a front sight in a tube with a luminous dot for night shooting and a rear peep sight adjustable for windage, mounted on a knurled mount and adjustable from 100 to 600 meters.
Characteristics Stgw 57
Caliber: 7.5mm (0.29")
Ammunition: 7.5 x 55
Overall length: 1.115 m (43.89")
Length with bayonet: 1.315 m (51.77")
Barrel length: 0.609 m (24")
Weight: 5.7 kg (12.58 lbs)
Magazine capacity: 6 or 24 rounds
Cyclic rate of fire: 450-500 rpm
Operation
This rifle functions by a bolt with semi-rigid locking by side rollers. The bolt is held open after the last shot. The manual bolt release lever is on the left side of the feed ramp.
Accessories
- Leather sling,
- cleaning kit placed in the pistol grip,
- headspace gauge,
- sight adjusting tools,
- 4 power scope or infrared night sight (30,000 rifles were equipped to receive a scope),
- Dagger-bayonet with stainless steel double edged blade, measuring 240 mm (9.44"). Grooved plastic handle, with an aluminium pommel. Scabbard same material as the grip, leather belt frog
- Fawn-coloured leather cartridge pouch for two magazines. Carefully made, this accessory is a true piece of leather working as only the Swiss were able to make.
Disassembly
Remove the magazine and see the rifle is safe. Remove the stock lock and turn it an eighth of turn in counter clockwise direction. Remove the stock while releasing the tension of the recoil springs. Extract spring assemblies from the stock. Take out cocking lever. Remove the bolt. Extract the mounting pin from the trigger assembly.
Reassembly
The reassembly is carried out in the inverse order and does not present any particular difficulty.
Variations
The SIG SG 510-1 is a version of the Stgw. 57 intended for export. It is about identical to the Swiss rifle of ordnance, but the fore stock is of wood (7.62 x 51). This model was tested by the U.S. Army in 1959.
The SIG SG 510-2 is an alternative reduced of the preceding weapon. The stock is of wood, the carrying handle and the bipod are removed (7.62 x 51). The arm was offered to the Netherlands and Sweden.
The SIG SG 510-3 is identical to the SG 510-4 with reduced dimensions. It does not have a grenade launcher. Offered to Finland, this model was chambered in 7.62 x 39 caliber and used the Kalashnikov magazine.
The SIG SG 510-4 is the export version of the Swiss Stgw. 57. It was manufactured by:
- Swiss industrial society, the Neuhausen-Fall-of-Rhine;
- Fabrica d' Armi Pietro Beretta, Gardone V.T. (Italy), 14,500 specimens in 1962-1963;
- FAMAE (Fabricas y Maestranzas del Ejercito), Santiago of Chile.
The SG 510-4 is close to Stgw. 57, except with regard to ammunition (7.62mm NATO), the stock and the forestock are made of beech. The bipod is assembled on a collar close to the front sight. In position of transport, it is folded up on the top of the barrel sleeve. The marks of the selector are S (safety), T or 1 (single shot), A or 20 (full automatic). The sights are a fixed front sight with ears and a peep rear sight cursor (100-600 m). Fed from a magazine inserted from below.
Accessories:
- Fabric sling,
- Blank firing attachment,
- Sighting grill for direct aiming of grenades,
- Sight with a level for indirect fire with grenades,
- Special magazine for grenade firing,
- Telescope sight,
- Cleaning kit, front and rear night sights placed in the pistol grip.
SIG SG 510 -4 was used by: Bolivia (army), Chile (army, airforce, navy, police and prison guards, Philippines (police). Another model intended for the civil market does exist. It receives a 10-round magazine and the stock and forend are in walnut. There is no grenade launcher.
Characteristics SIG 510-4
Caliber: 7.62mm (.30")
Ammunition: 7.62 x 51
Overall length: 1.015 m (40")
Barrel length: 0.505 m (20")
Weight: 4.45 kg (9.82 lbs)
Magazine capacity: 10 or 20 shots
Cyclic rate of fire: 500-650 rpm
SIG SG 510-5
Model in .30-06, tested by Mexico in 1969.
The SIG SG 510-6 is a modernized version of the Stgw 57 (7.5 x 55). Proposed to the Swiss Army in 1981, it was not accepted.
Tests
Our test specimen is a semiautomatic version of the Stgw 57 as it is available in Switzerland and accessible there to all shooters. The ammunition used during the tests was surplus of the type GP 11. The cases were produced in Dornach and the cartridges loaded in April 1979 by Altdorf. The test included the use of the bipod in both the front and back positions though the locking of the bipod legs lacks stability. The magazine, which contains 24 cartridges, is easy to load by hand. The recoil of the weapon is not severe. The fired cases are ejected through the ejection port and are slightly marked. It should be noted that it is not possible to eject a loaded cartridge by the ejection port which is too short. It is necessary to remove the magazine and the cartridge then falls out the bottom.
Accuracy is acceptable judged by the result of our target (grouping of 12 x12 cm at 100 m or 5" x 5" at 110 yards). We had some stoppages due to feed problems that resulted from poor positioning of the cartridge in the magazine. At the end of several dozen shots, the weapon was very dirty, in particular around the chamber, which detracted from its overall performance.
This article first appeared in Small Arms Review SAW (October 2012) |
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