SIG SG 510

SIG SG 510
Sturmgewehr 57 (Stgw 57)
Type	Battle rifle
Place of origin	Switzerland
Service history
In service	1957–1990
Used by	See Users
Wars	1973 Chilean coup d'état
Production history
Designer	Rudolf Amsler
Designed	1950s
Manufacturer	Schweizerische Industrie Gesellschaft (SIG)
Produced	1957–1983
Variants	SG 510-1, SG 510-2, SG 510-3, SG 510-4
Specifications
Weight	5.7 kg (12.57 lb) (Stgw 57) 4.37 kg (9.63 lb) (SG 510-4)
Length	1,100 mm (43.3 in) (Stgw 57) 1,015 mm (40.0 in) (SG 510-4)
Barrel length	583 mm (23.0 in) (Stgw 57) 505 mm (19.9 in) (SG 510-4)
Cartridge	7.5×55mm GP 11 (Stgw 57) 7.62×51mm NATO (SIG 510-4)
Action	Roller-delayed blowback
Rate of fire	450–600 rounds/min
Muzzle velocity	750 m/s (2,460 ft/s)
Effective firing range	640 m (700 yd) iron sights 800 m (875 yd) Kern 4×24 optical sight
Feed system	20-, 24-, or 30-round detachable box magazine
Sights	Front post, rear aperture

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 roller-delayed blowback system similar to the H&K G3 and CETME rifles. The SIG SG 510-1 entered service in the Swiss Army with the designation Fass 57 (French/Italian, for Fusil d'Assault 57/Fucile d' Assalto 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 was, in 1990, replaced by the lighter SIG SG 550, although some reservists used it for several years longer.

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.

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 520 mm (20.5 in) 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.