The Sturmgewehr 57 (Stgw. 57 ) is a

selective fire Selective may refer to: * Selective school, a school that admits students on the basis of some sort of selection criteria ** Selective school (New South Wales) See also * Selective breeding Selective breeding (also called artificial select ...

battle rifle A battle rifle is a service rifle chambered to fire a fully powered cartridge. The term "battle rifle" is a retronym created largely out of a need to differentiate automatic rifles chambered for fully powered cartridges from automatic rifles cha ...

Schweizerische Industrie Gesellschaft SIG Group AG is a Swiss multinational corporation and one of the biggest manufacturers in the packaging industry. Originally founded 1853 as a railway car producer named ''Schweizerische Waggonfabrik'' ("Swiss Wagon Factory"), it was renamed ...

(now SAN Swiss Arms) of Switzerland. The Stgw. 57

assault rifle An assault rifle is a select fire rifle that uses an intermediate cartridge, intermediate-rifle cartridge and a Magazine (firearms), detachable magazine.C. Taylor, ''The Fighting Rifle: A Complete Study of the Rifle in Combat'', F.A. Moyer '' ...

uses a roller-delayed blowback system similar to the blowback system of the

Heckler & Koch G3 The Heckler & Koch G3 () is a selective fire, select-fire battle rifle chambered in 7.62×51mm NATO developed in the 1950s by the German firearms manufacturer Heckler & Koch, in collaboration with the Spanish state-owned firearms manufacturer CE ...

(H&K G3) and

CETME CETME () is a Spanish government design and development establishment. While being involved in many projects CETME was mostly known for its small arms research and development. The Spanish government hired former semiautomatic weapon designers f ...

rifles. As an assault rifle, the model AM 55 entered service in the

Swiss Army The Swiss Armed Forces (; ; ; ; ) are the military and security force of Switzerland, consisting of land and air service branches. Under the country's militia system, regular soldiers constitute a small part of the military and the rest are ...

in three designations F. ass. 57 7.5mm (Fr: Fusil d’Assaut; Ital: Fucile d’Assalto 1957) and 7.5mm Stgw. 57 (Ger: Sturmgewehr 1957). Technologically, the Stgw. 57 was the mechanical and design basis for the export-variations of the SG 510 family of small arms. After thirty-three years, from 1957 to 1990, the Swiss Army replaced the Stgw. 57 with the

SIG SG 550 The SG 550 is an assault rifle manufactured by SIG Sauer AG (formerly a division of Schweizerische Industrie Gesellschaft, now known as SIG Holding AG) in Switzerland. "SG" is an abbreviation for ''Sturmgewehr'' ("assault rifle"). The rifle is ...

, a lighter-weight assault rifle.

Development

The Stgw. 57 assault rifle was developed during the late 1950s, with the in-house model name of AM 55, at

SIG Combibloc Group SIG Group AG is a Swiss multinational corporation and one of the biggest manufacturers in the packaging industry. Originally founded 1853 as a railway car producer named ''Schweizerische Waggonfabrik'' ("Swiss Wagon Factory"), it was renamed ...

(SIG). During development, Rudolf Amsler was the principal designer at Schweizerische Industrie Gesellschaft. Mechanically, the Stgw. 57 is a

rifle that employs a roller-delayed blowback operating system. In military service, the Swiss Army issued the Stgw. 57 as the personal weapon of every soldier. In the course of service, the Stgw. 57 replaced the following four weapons: (i) the

K31 The Karabiner Modell 1931 (officially abbreviated to Kar. 31/Mq. 31; commonly but incorrectly known in civilian circles as the K31) is a magazine-fed, straight-pull bolt-action rifle. It was the standard-issue rifle of the Swiss armed forces fro ...

rifle, (ii) the Suomi M-31/Mp. 43/Mp. 44 submachine gun, (iii) the

Lmg 25 The ''Leichtes Maschinengewehr Modell 1925'' (shortened to Lmg 25) is a Switzerland, Swiss recoil operated light machine gun designed by Colonel Adolf Furrer of Waffenfabrik Bern in the 1920s and produced from 1925 to the 1960s. It was the first m ...

light machinegun, and (iv) in the 1974–1977 period, replaced the Zf. Kar. 55 sniper's rifle.

Design details

The weapon is mainly made of pressed sheet-metal components to ease mass production and incorporates the "straight-line" recoil configuration. This layout, placed both the

center of gravity In physics, the center of mass of a distribution of mass in space (sometimes referred to as the barycenter or balance point) is the unique point at any given time where the weighted relative position of the distributed mass sums to zero. For ...

and the position of the shoulder stock nearly in line with the longitudinal axis of the bore, a feature increasing controllability during burst or automatic fire. The Stgw. 57 has a distinctive T-shaped bolt handle similar to the earlier K31 rifle. As with all roller-delayed designs, the roller recesses and rollers in the receiver will eventually wear down, decreasing the bolt head to bolt carrier gap. Many roller-delayed blowback weapons accept this as the functional service life of the rifle, but the Stgw. 57 has interchangeable locking recesses, so they can be replaced when worn. The solid neoprene rubber, fixed butt-stock was designed with durability in mind and dynamically deforms to cope with the recoil produced by heavy

rifle grenades A rifle grenade is a grenade that uses a rifle-based launcher to permit a longer effective range than would be possible if the grenade were thrown by hand. The practice of projecting grenades with rifle-mounted launchers was first widely used dur ...

. The Stgw. 57 sports a large carrying handle at its balance point that can be used during quick position changes or on the march. The ribbed handguard of the Stgw. 57 is also molded out of solid neoprene rubber.

Barrel

The Stgw. 57's barrel is relatively thick and rifled along of its length and has a 270 mm (1 in 10.6 in) 4 groove rifling. At the end of the barrel an integral long

muzzle brake A muzzle brake or recoil compensator is a device connected to, or a feature integral (ported barrel) to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter re ...

flash hider A flash suppressor, also known as a flash guard, flash eliminator, flash hider, or flash cone, is a device attached to the muzzle of a rifle that reduces its visible signature while firing by cooling or dispersing the burning gases that exit t ...

is fitted that reduces recoil by about 25%. A rifle grenade-launching interface is also integrally machined into the body of the barrel. The barrel is surrounded by a perforated tubular aluminium barrel jacket with two spring detents for a sliding, underfolding integrated

bipod A bipod is a V-shaped portable attachment that helps support and steady a device, usually a weapon such as a long gun or a mortar. The term comes from the Latin prefix and Greek root , meaning "two" and "foot" respectively. Bipods are design ...

—one near the muzzle to reduce shot dispersion during automatic fire, and another nearer the receiver and balance point offering more flexibility in the rifle role. The Stgw. 57 bipod legs are marked for use as an

inclinometer An inclinometer or clinometer is an measuring instrument, instrument used for measuring angles of slope, elevation, or depression (geology), depression of an object with respect to gravity's direction. It is also known as a ''tilt indicator'', ' ...

for aiming rifle grenades at various ranges with and without an additional booster-charged rifle grenade. For such indirect rifle grenade fire, the Stgw. 57 was set on the ground and a weighted string attached on the sling loop was used as a plumb-line to set the correct firing angle reference mark on the appropriate bipod leg (left for boosted, right for unboosted). Swiss army knives were used as a makeshift

plumb bob A plumb bob, plumb bob level, or plummet, is a weight, usually with a pointed tip on the bottom, suspended from a string and used as a vertical direction as a reference line, or plumb-line. It is a precursor to the spirit level and used to esta ...

at the end of a string.

Trigger mechanism

The trigger mechanism has a three-position fire selector switch that is also the manual safety toggle that secures the weapon from accidentally discharging. The user selects the operating mode with a large side lever on the left side of the trigger pack that can be rotated to select S (safe), E (semi-automatic fire) or M (full-automatic fire). On the right hand side of the rifle, there is a foldaway 'winter' trigger which enables the operator to use the rifle with arctic mittens. It is also used for rifle grenade firing to avoid recoil-induced hand injuries.

Sights

The Stgw. 57 has a straight-line stock design, and an elevated

iron sights Iron sights are a system of physical alignment markers used as a sighting device to assist the accurate aiming of ranged weapons such as firearms, airguns, crossbows, and bows, or less commonly as a primitive finder sight for optical telescop ...

line with a relatively long sight radius. Both the front and rear sights can be folded down when not in use. The rear

peep sight Iron sights are a system of physical alignment markers used as a sight (device), sighting device to assist the accurate aiming of ranged weapons such as firearms, airguns, crossbows, and Bow and arrow, bows, or less commonly as a primitive finde ...

of the Stgw. 57 can be adjusted from . From the sight adjusts in increments. From in increments, and from in increments.Swiss Army Sturmgewehr 57 Manual (German)
/ref> For low-visibility use, a reversible clip-on diopter with two self-luminous tritium-powered inserts (later carbon-14, one-side only) fitted laterally on each side of the aperture was issued. This element could be clipped by the user on the standard diopter. The front sight hood contained a permanently attached single strontium-90 or tritium-powered insert above the post to complete the low visibility sight line. When not in use, the low-light diopter is stored inside the pistol grip cavity, with two blister packets of weapon grease. The useful life expectancy of tritium-illuminated night sight inserts is roughly 7-10 years. According to the Swiss Army, the 50% windage and elevation dispersion shot at 300 m from a machine rest averages 6 cm (2.4 in). The employed

circular error probable Circular error probable (CEP),Circular Error Probable (CEP), Air Force Operational Test and Evaluation Center Technical Paper 6, Ver 2, July 1987, p. 1 also circular error probability or circle of equal probability, is a measure of a weapon s ...

method cannot be converted and is not comparable to US military methods for determining rifle accuracy. When the R₅₀ results are doubled the hit probability increases to 93.7%. For anti-personnel use, the Stgw. 57 typical maximum range for consistent accuracy is . For

designated marksman A designated marksman (DM), squad advanced marksman (AD) or squad designated marksman (SDM) is a military marksman role in an infantry squad. The term ''sniper'' was used in Soviet doctrine although the soldiers using the Dragunov SVD were the ...

use, some special variants of the Stgw. 57 can be equipped with a quick-detachable Kern & Co Aarau 4×24

telescopic sight A telescopic sight, commonly called a scope informally, is an optical sighting device based on a refracting telescope. It is equipped with some form of a referencing pattern – known as a ''reticle'' – mounted in a focally appropriate p ...

. The sight weighs and includes a variety of features, such as a Bullet Drop Compensation (BDC) elevation adjustment knob for ranges from 100 to 800 m, a tritium-illuminated reticle that enables target acquisition in low-light conditions and a diopter eyesight correction adjustment. Included with the sight is a lens hood with additional protective lens and a gray filter for glare reduction. A night vision sight with an infrared light can also be mounted. The Chilean version can fit a German-made Supra 4×24 telescopic sight.

Accessories

The Stgw. 57 is fed from curved detachable box magazines, made from aluminum and containing 24 rounds weighing empty and fully loaded. Special silver-colored magazines that can contain 6 grenade-launching cartridges (Gw. Treib.-Pat. 44) for use with rifle grenades weigh empty and fully loaded. The Stgw. PE-57 had 6-round magazines available as well. Magazines with 20-round capacities for the SG 510-4 in 7.62 NATO and 30-round originally for the Lmg. 25 may operate in the Stgw. 57 as well. Other accessories include a leather sling, a

bayonet A bayonet (from Old French , now spelt ) is a -4; we might wonder whether there's a point at which it's appropriate to talk of the beginnings of French, that is, when it wa ... , now spelt ) is a knife, dagger">knife">-4; we might wonder whethe ...

, various magazine pouches, cavalry holsters, and fortress-firing kits. Rocket-boosted

rifle grenade A rifle grenade is a grenade that uses a rifle-based launcher to permit a longer effective range than would be possible if the grenade were thrown by hand. The practice of projecting grenades with rifle-mounted launchers was first widely used dur ...

s can be launched with the use of the aforementioned silver-colored magazine. Grenade-launching cartridges enable the Stgw. 57 to fire ''Gewehrgranaten 58'' rifle grenades which weigh depending on the warhead type. These rifle grenades achieve a muzzle velocity of and a maximum range of without the help of a booster charge or a V7 of and a maximum range of with the help of a booster charge. Rifle grenade variants include: * Gw. HPz. G. 58: Hollow charge for heavy armor (direct-fire only), rated for ca. 280-320mm of penetration in rolled homogenous armor. * Gw. St. G. 58: Anti-personnel fragmentation with impact detonator (direct or indirect-fire). * Gw. Nb. G. 58: Smoke canister for reducing visibility (direct or indirect-fire). * Gw. UG 58: Practice (inert orange rubber), with or without booster charge.

Civilian use

Upon completion of their military service, members of the

Swiss armed forces The Swiss Armed Forces (; ; ; ; ) are the military and security force of Switzerland, consisting of land and air service branches. Under the country's militia system, regular soldiers constitute a small part of the military and the rest are ...

could obtain ownership of their personal Stgw. 57 rifle by paying an administrative fee. These "civilianised" Stgw. 57 rifles were converted to a semi-automatic only configuration. Dedicated factory-built, semi-automatic only rifles for private purchase were available and designated PE-Stgw. 57, PE means ''Privat Einzelfeuer'' ("private single fire"). These civilian rifles incorporate subtle design changes to avoid some cross-compatibility with army rifle parts. As of 2007, around 40 percent of discharged soldiers choose to retain their weapon (nowadays the

), and the going rate for civilianised Stgw. 57 rifles on the private weapons market is reported to vary between 300 and 500

Swiss franc The Swiss franc, or simply the franc, is the currency and legal tender of Switzerland and Liechtenstein. It is also legal tender in the Italian exclave of Campione d'Italia which is surrounded by Swiss territory. The Swiss National Bank (SNB) iss ...

s. In Switzerland, the Stgw. 57 is also used for target shooting matches. For this the standard iron sights can be replaced by target shooting diopter and

globe sight A globe sight is a front Sight (device), sight component used to assist the aiming of a gun/device, usually those intended to launch projectiles, such as firearms, airguns, and crossbows. It is found in particular as a front sight element on rifl ...

sighting lines. When the original sighting is kept Swiss sport shooters refer to a such unmodified rifle as Stgw. 57/02 (small diopter allowed, but no globe sight). When a globe sight is added and possibly the sighting line radius is lengthened by mounting the globe sight nearer to the muzzle it is referred to as Stgw. 57/03. As of 2017, original military barrels, which are known for longevity and are rated for up to 15,000 rounds (for later nitrided variants), could be replaced by match-grade barrels. Other upgrades include improved target sights, mirage bands, lighter hammers, custom pistol grips, custom barrel jackets and regular replacement of bolt components.

SG 510-4 (7.62×51mm NATO variant)

The SG 510-4 chambered in

7.62×51mm NATO The 7.62×51mm NATO (official NATO nomenclature 7.62 NATO) is a rimless, straight walled, bottlenecked, centerfire rifle cartridge. It is a standard for small arms among NATO countries. First developed in the 1950s, the cartridge had first be ...

was adopted by Chile and Bolivia. Compared to the SG 510-1, the following main changes were applied: * Lighter, shorter (505mm) barrel with 8 (early), or 16 (late) chamber flutes, 304.8mm (1 in 12 inch) twist rate * Revised delay angle on the bolt carrier wedge * Straight 20-round box magazine with feed path insert to accommodate for the shorter cartridge * New low-profile iron sights, with ramp-adjustable rear sight aperture and semi-hooded front sight * Spring-loaded detent on the front barrel jacket bushing/front sight base for rifle grenade sight * Angled stock tube and stock assembly, with correspondingly modified recoil spring assembly and bolt carrier tail * Walnut wood stock and handguard * New pistol grip design (after ca. 1966) * Lightened roller recesses and winter trigger * Simplified bolt carrier with add-on, unified rubber buffer and charging handle lug The SG 510-4 is officially classed as an automatic rifle but also served as a designated marksman weapon (in Chile with Supra 4×24 scope).

Variants

* AM 55: Original version as adopted by the Swiss Army as "7,5mm Stgw. 57". * SG 510-1: Export model of the AM 55 chambered in 7.62×51mm NATO. * SG 510-2: Lightened variant of the SG 510-1.Stgw. 57 / Sig 510 assault rifle (Switzerland)
. Modern Firearms. Accessed 15 August 2009. * SG 510-3: 7.62×39mm variant with shorter barrel, receiver and barrel jacket. This was produced in small numbers as a prototype and submitted to the Finnish Army. This model of the rifle was never mass-produced. * SG 510-4:

variant used by Bolivia and Chile. This version uses a shorter barrel and a buttstock made from wood rather than rubber. Overall length is much less than the Stgw 57 with a subsequently lower weight. The buttstock and stock tube are angled downward rather than straight inline with the receiver. * SG 510-5:

.30-06 Springfield The .30-06 Springfield cartridge (pronounced "thirty- aught-six" ), 7.62×63mm in metric notation, and called the .30 Gov't '06 by Winchester, was introduced to the United States Army in 1906 and later standardized; it remained in military us ...

(7.62×63mm) experimental rifle made for testing by the Mexican Government. * SG 510-6: 7.5×55mm Swiss test batch of rifles based on the SG 510-4 in the Swiss military chambering intended to replace the heavier Stgw 57. The rifles were only built for testing and were no longer considered after 1980s trials. * SG 510-7 T / SIG-AMT: semi-automatic only variant of the SG 510-4 imported into the United States in relatively small numbers. It was available in .308 (7.62×51). "AMT", term used after 1969, stood for "American Match Target". It was equipped with fine wooden furniture and could be ordered with a rounded upper handguard. * ''Gewehr 2'' (G2): 7.62×51mm NATO variant procured by the

Bundeswehr The (, ''Federal Defence'') are the armed forces of the Germany, Federal Republic of Germany. The is divided into a military part (armed forces or ''Streitkräfte'') and a civil part, the military part consists of the four armed forces: Germ ...

for trials in 1956, which eventually lost to what would become

. * PE-Stgw. 57: (Privat Einzelfeuer) semi-automatic only civilian version of the AM 55 available in 7.5×55mm GP 11 Swiss. This variant is not the same as privatized former Swiss Army service rifles. It was specifically built as a semi auto only rifle along the lines of the Stgw. 57 with which it is frequently confused. While over 700,000 of the Stgw. 57s were built for military use, less than 5000 PE-Stgw. 57s were made.

Users

Swiss Tank Crew Provide Airport Security During Palestine Conference 1983

*: ''SG 510-4'' variant.Jones, Richard D. Jane's Infantry Weapons 2009/2010. Jane's Information Group; 35 edition (January 27, 2009). . * *: Used by the ''

Compagnie des Carabiniers du Prince The (; " Prince's Company of Carabiniers") is the Infantry branch of the '' Force Publique'', and one of the limited number of militaries that recruits foreigners. Although Monaco's defence is the responsibility of France, Monaco maintains a sm ...

''. *: Adopted by the

in 1957. * *

Gallery

File:Fass57-diag.jpg, Stgw 57 with iron sights, bayonet and folded bipod. On display at

Morges Morges (; , Plurale tantum, plural, probably Ablative (Latin), ablative, else dative; ) is a Municipalities of Switzerland, municipality in the Switzerland, Swiss Cantons of Switzerland, canton of Vaud and the seat of the Morges District, distri ...

castle museum. File:Fass57-p1000490.jpg, Stgw 57(/03) modified for sport shooting with a diopter and globe sight sighting line. File:Fass57-p1000721.jpg, Receiver of a Stgw 57, seen from the right. File:Fass57-p1000494.jpg, Receiver of a Stgw 57(/03) modified for sport shooting, seen from the left. File:Demontiert Stgw 57.JPG, Stgw 57 dismantled. File:Stgw, Verschluss, Feder.JPG, Stgw 57, bolt, recoil spring. File:Fass57 Dispositif de détente.JPG, Stgw 57 trigger housing with winter trigger extended. File:Baïonnette Fass 57.JPG, Stgw 57 bayonet and frog. File:Trousse de nettoyage Fass 57.JPG, Stgw 57 cleaning kit pouch. File:Grenades à fusil 58.JPG, Left to right; boosted and unboosted orange training and a Gw HPz G 58 armour piercing rifle grenades File:Gw HPz G 58.JPG, Gw HPz G 58 armour piercing hollow charge rifle grenade poster File:Gw St G 58.JPG, Gw St G 58 fragmentation rifle grenade poster File:Gw Nb G 58.JPG, Gw Nb G 58 smoke rifle grenade poster

References

External links

Modern FirearmsBiggerhammer.netSchiessschule Walenstadt

Swissrifles.comGunco.netStarting portal for articles, information and manuals, etc. on the Stgw 57/SG 510/AMT and SG 550 rifle series
{{Sturmgewehr 45 derivatives 7.5×55mm Swiss firearms 7.62×51mm NATO battle rifles Rifles of the Cold War Rifles of Switzerland Roller-delayed blowback firearms Military equipment introduced in the 1950s Weapons and ammunition introduced in 1957 SIG Sauer rifles