SIG SG 542
SIG (Schweizerische Industrie Gesellschaft) · Battle Rifle · Out Of Production · 1979
Also known as: SG 542, Sturmgewehr 542, SG-542
Overview
The SIG SG 542 is the 7.62x51mm NATO battle-rifle member of SIG's modular SG 540 family, developed at Schweizerische Industrie Gesellschaft in Neuhausen am Rheinfall and introduced at the end of the 1970s. Where the 5.56mm SG 540 became an export success, the full-power SG 542 was conceived for customers who wanted the same gas-operated, rotating-bolt action in a harder-hitting cartridge. Mechanically it is a conventional long-stroke gas piston design with a multi-lug rotating bolt - a deliberate departure from the heavy, expensive roller-delayed Stgw 57 it nominally succeeded in SIG's catalogue - which made it far lighter (3.55 kg empty) and cheaper to produce through extensive use of stamped-steel construction. The rifle feeds from 20-round detachable box magazines, fires select-fire from a hammer mechanism, mounts a folding bipod along the forearm, and can launch rifle grenades. Because Swiss federal export restrictions limited domestic manufacture of the series, much SG 540/542 production was licensed to the MANURHIN plant at Mulhouse in France, and the rifle saw adoption and combat use across Africa, Asia and South America. The 542's heavier recoil meant it was usually fitted with a fixed polymer stock rather than a folding one.
Specifications
| Weight (empty) | 3550 g (125.2 oz) |
| Overall Length | 1000 mm (39.37") |
| Barrel Length | 465 mm (18.31") |
| Action Type | Gas Operated Long Stroke |
| Firing Mechanism | Hammer Fired |
| Trigger Type | Single Stage |
| Magazine Capacity | 20 rounds |
| Magazine Type | Detachable Box |
| Muzzle Velocity | 820 m/s (2690 fps) |
| Muzzle Energy | 3204 J (2363 ft·lbf) |
| Effective Range | 600 m (656 yd) |
| Maximum Range | 3000 m (3281 yd) |
| Rate of Fire | 700 rpm |
| Barrel Rifling | Right Hand |
| Rifling Twist | 305 mm (12.01") |
| Number of Grooves | 4 |
| Frame Material | Steel |
| Barrel Material | Steel |
| Stock Material | Polymer |
| Finish | Phosphate |
Calibers
- 7.62x51mm NATO · primary · 7.62x51mm NATO — also known as .308 Winchester, 7.62 NATO, .308 Win
Features
- Firing modes: Semi Automatic, Full Automatic
- Feed systems: Detachable Box Magazine
- Safety mechanisms: Manual Safety Selector
- Features: Gas Operated Rotating Bolt, Select Fire, Folding Bipod, Stamped Steel Construction, Flash Hider, Rifle Grenade Capable, Adjustable Diopter Sights, Optics Mount, Winter Trigger Capable
Variants
- SIG SG 540 (5.56x45mm parent model) — Caliber
- SIG SG 543 (carbine) — Carbine
Service history
Operators
- Swiss Armed Forces · as SG 542
- French Armed Forces · as SG 542
Production
Production years: 1979-1990s
Less commercially successful than the 5.56mm SG 540; much of the SG 540/542 series was produced under license by MANURHIN in Mulhouse, France, owing to Swiss export restrictions
Origin
Country of origin: Switzerland
Designer: SIG Neuhausen engineering team
Notes
Action type is widely reported as gas-operated with a rotating bolt (long-stroke piston), the same operating principle as the parent SG 540; militaryfactory.com lists it as 'delayed blowback', which appears to be an error - weaponsystems.net and most references describe the SG 540 series as gas-operated. Barrel length 465 mm; overall length 1000 mm with fixed stock. Rate of fire is variously cited between 650 and 800 rpm. Much production occurred under license at MANURHIN (France) due to Swiss export rules. The shortened SG 543 carbine variant has a folding stock.
Background
Switzerland's strict arms-export laws meant SIG could barely sell its own rifles abroad - so the gas-operated SG 540 family, including the 7.62mm SG 542, was largely built across the border at MANURHIN in France to reach the African, Asian and South American buyers Bern would not license directly.