The SIG 556 is the U.S. made version of the SIGARMSÃ‚Â® SG 550. The SIG 556 showcases the same high-end and premier performance two position adjustable gas piston operating rod system.
The system was engineered by SIG's sister company Swiss Arms and combines it to a trigger housing that cuts the rifle's weight by a pound and is designed to accept standard AR magazines. The SIG 556 additionally features a 16" military grade cold hammer forged barrel, tightly chambered in 5.56mm NATO, with quality twist rate of 1 in 7".
The forged forearm housing the gas operating system is ergonomically vented by non-slip polymer featuring the exclusive SIG TriRail design with three fully integrated Picatinny rails for mounting various accessories. The optional and removable flip up front combat sight is adjustable for elevation and windage. The Picatinny rail enhanced receiver is made of superior strength carbon steel with a heavy duty wear-resistant Nitron X rifle finish.
The contoured trigger housing is constructed from a heat treated aircraft grade aluminum alloy with an anodized finish designed to survive all types of extreme conditions. The assault rifle comes featuring a smooth two-stage trigger. The SIG 556 also showcases an ambidextrous safety and is specifically designed to accept standard AR magazines. A 30-round, high quality magazine is supplied with each rifle.
Spare battery compartments are generously provided in the practically designedrubber padded watertight adjustable butt stock as well as the pistol grip. Sling attachment points are also offered on the butt stock.
SIGARMS also offers the SIG 556 SWAT. The SWAT model will showcase the same compact and ergonomic design of the standard SIG 556 with 16" barrel however will feature a tactical quad rail and a flat top Picatinny railed receiver. These two SIG rifles are the first of several new SIG 556 models that are currently in development at SIGARMS.