SIG SG 510 The SIG SG 510 or Sturmgewehr 57 is a selective fire battle rifle manufactured by Schweizerische Industrie Gesellschaft ( now SAN Swiss Arms ) of Switzerland . It uses a similar roller - delayed blowback system to the H & K G3 and CETME rifles . It also has a SAW counterpart akin to the American Stoner 63 . The SIG SG 510 - 1 entered service in the Swiss Army with the designation Fass 57 ( French , for Fusil d ' Assaut 57 " ) or Stgw 57 ( German for Sturm Gewehr 57 " ) . The Sturmgewehr 57 / SIG SG 510 - 1 was adopted for Swiss military service in 1957 and has been replaced by the lighter SIG SG 550 in year 1990 , although some reservists used it several years longer . Design details . The SG 510 is derived from the AM55 used during the 1950s . It is a selective fire rifle that employs a roller - delayed blowback operating system . Unusually , it was fitted with a shiny stainless steel bayonet . Features . The weapon is mainly made of pressed sheet - metal components to ease mass production . The SG 510 has a distinctive T - shaped bolt handle similar to the earlier K31 . The butt - stock and hand guard of the rifle are rubberized for comfort and durability and the front hand guard is ribbed to provide a better grip . The SG 510 - 1 / Stgw 57 barrel is 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 muzzle brake is fitted that reduces recoil by about 25 % . The barrel is surrounded by a perforated tubular barrel jacket with two mounting points for an integral bipod — one near the muzzle , and another near the receiver . The SG 510 - 4 chambered in 7 . 62×51mm NATO with a 305 mm ( 1 in 12 in ) twist rate barrel was adopted by Chile and Bolivia . The SIG SG 510 is officially classed as an automatic rifle but served as a designated marksman weapon ( in Chile with Supra 4×24 scope ) . For recoil reduction the fixed butt - stock is fitted with a recoil buffer . The SG 510 - 1 / Stgw 57 sports a large carrying handle at its balance point that can be used during quick position changes or on the march . 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 also improves accuracy , because it reduces the force needed to pull the trigger . 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 receiver that can be rotated to select S ( safe ) , E ( semi - automatic fire ) or M ( full - automatic fire ) . Sights . The SG 510 - 1 / Stgw 57 has a straight - line stock design , and an elevated iron sights line . Both the front and rear sights can be folded down when not in use . The rear peep sight of the Stgw 57 can be adjusted from 100 m to 640 m . From 100 – 200 m the sight adjusts in 50 m increments . From 200 – 300 m in 30 m increments , and from 300 – 640 m in 20 m increments . 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 ) . For anti - personnel use , the SG 510 - 1 / Stgw 57 typical maximum range for consistent accuracy is 600 m ( 656 yd ) . For designated marksman use , the SG 550 can be equipped with a quick - detachable Kern 4×24 telescopic sight . The sight weighs and includes a variety of features , such as mounting components , a Bullet Drop Compensation ( BDC ) elevation adjustment knob for ranges from 100 to 600 m , an illuminated reticle that enables target acquisition in low - light conditions and a diopter eyesight correction adjustment . Included with the sight is a lens hood for mounting on the ocular that reduces image quality - impairing stray light and a gray filter for glare reduction . A night vision sight with an infra red light can also be mounted . The Chilean version can fit a German - made Supra 4×24 telescopic sight . Accessories . The Swiss Army Stgw 57 is fed from curved detachable box magazines , made from aluminum and containing 24 rounds . Magazines with 20 and 30 - round capacities are also available . Other accessories include the sling , the PE57 bayonet , and a special small - capacity magazine for grenade - launching cartridges . Rifle grenade s can be launched without adding a special provision . Grenade - launching cartridges enable the SG 510 - 1 / Stgw 57 to fire Gewehrgranaten 58 rifle grenades . The rifle grenade 58 achieves a muzzle velocity of 35 m / s and a maximum range of 125 m without the help of a booster charge or 70 m / s and a maximum range of 400 m with the help of a booster charge . The rifle grenade 58 may be fitted with the following warheads : Civilian use . Upon completion of their military service , members of the Swiss armed forces could obtain ownership of their personal SG 510 rifle by paying an administrative fee . These " civilianised " rifles were converted to a semiautomatic only configuration . As of 2007 , around 40 percent of discharged soldiers choose to retain their weapon ( nowadays the SIG SG 550 ) , and the going rate for civilianised SG 510 rifles on the private weapons market is reported to vary between 400 and 500 Swiss franc s . In Switzerland the SG 510 is also used for target shooting matches . For this the standard iron sights can be replaced by target shooting diopter and globe sight sighting lines . When the sighting line radius is kept at its original length Swiss sport shooters refer to a such modified rifle as Stgw 57 / 02 . When the sighting line radius is lengthened by mounting the globe sight nearer to the muzzle it is referred to as Stgw 57 / 03 . See also . Related weapons :