SIG SG 550

The SIG SG 550 is a Swiss assault rifle developed by SIG Sauer's predecessor Schweizerische Industrie-Gesellschaft, entering production in 1986 and adopted by the Swiss Armed Forces in 1990 as the Stgw 90, replacing the earlier SIG SG 510. Gas-operated with a rotating bolt and chambered for 5.56x45mm NATO, the rifle was built to a demanding standard of reliability and mechanical accuracy, feeding from distinctive translucent polymer magazines that can be clipped together for faster reloading, and it was produced in a shortened SG 551 carbine variant and a compact SG 552 commando variant alongside the full-length service rifle. More than six hundred thousand SG 550-family rifles have been produced, and beyond Swiss service the design has been used by military and police special-forces units in a number of other countries.