The SIG SG 552 Commando is a Swiss, 5.56mm, automatic assault rifle. Being a derivative version of the SG 550, it is in service with the Swiss Army since 1998 and with Spanish National Police elite unit “Grupo Especial de Operaciones” since 2000. It is gas-operated, with a piston system, and shoots from closed bolt 5.56x45mm NATO ammunition, using a 30-round polymer box magazine. This piston-driven, gas-operated system renders the rifle a lot more reliable for a longer period of usage without being cleaned than the direct impingemente gas operation used in the M16. It is extremely accurate as it has a very light recoil and dependable self-loading system. Equipped with a folding stock and a shorter barrel than the original model, the SG 552 is a light and compact assault rifle, which features an ambidextrous safety, fire selector lever, located just above the handgrip on both side of weapon, and Picatinny rail for optical sight accessory. The rifle fire selector has provision for single-shot, 3-round burst, and full automatic fire. The cocking handle and ejection port are found on the right hand side of rifle. It is the ideal assault rifle for special forces operations against terrorist cells in house-to-house urban fighting. Muzzle velocity: 750 m/s. Effective range: 400 m.