SIG SG 542

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.