SIG SAUER 550

The SIG 550 is a highly accurate, mass-produced assault or as some would like to call it 'sniper' rifle manufactured by SAN Swiss Arms Switzerland. The weapon has an AK-47-type action. The SIG 550 is the standard issue rifle of the Swiss Armed Forces. The U.S. federal agencies and other Special Forces all over the world use its variant the SIG 551. The SIG 550 was developed from the earlier SIG 540 and SIG 541 models, and was a competitor for the Swiss Army Assault Rifle contest of 1979 to 1980. Winning the competition 1983 it was renamed the Sturmgewehr 90 in German and F ass 90 - for Fusil d'assaut. Large-scale production only began in 1986, and it replaced the SIG 510. The SIG 550 uses the Gw Pat.90 5.6 mm ammunition, this is designed for nominal use at 300 meters and can be actually interchangeable with standard 5.56 x 45 mm NATO ammunition.

However the Gw Pat.90 ammunition is optimized for the SIG 550's rifling twist rate of 1 in 10 and provides better performance. It uses 20-round or 30-round magazines, and accurate out to 400 meters without optics and 600 meters with optics.The SIG 550 weighs 4.05 kg without magazine, and is 998 mm with the stock open, and 772 mm with the stock folded. The barrel length is 528 mm or 20.8 inches. It has a gas operated, rotating bolt action with a rate of fire of 700 round per minute. The rotating drum sights has four ranges, that is 300 m, 200 m, close combat and night, there is a built-in tritium sight for night aiming. Some of features that ensure exceptional accuracy are the heavy, fixed barrel with chamber and bore simultaneously hammer-forged along with he superb trigger action. The diopter and snapshooting sights are optimized, and are adjustable for windage and elevation. It has a closed weapon system that makes it more reliable.

All the SIG series of weapons - the SIG 550/551/552 rifles are equipped with semi-transparent plastic magazines. This may be locked together to help in faster reloading. The muzzle also has a metallic piece whose dilatation shows the temperature of the barrel. The ergonomically correct stock design helps in for fast locking into the shoulder and quick target sites. It is easy to use for both right and left handed people and all controls are within sight. The multipack magazine system and bolt holds open device for quick magazine change. All this makes it superb for easy handling during combat situations. It is designed with weight saving options that reduces fatigue. It can also be maintained quickly and has undergone stringent dust, sand mudbath, low temperature and winter trials under extreme conditions in the Swiss Alps along with troop trials with live ammunition. The SIG 550 won with flying colors, and was issued the highly rated qualification of the Swiss army of field grade. This is definitely the weapon of choice for an army priding itself on efficiency.