The Sig Sauer Sig 556 Patrol Rifle is a semi-automatic tactical rifle chambered in 5.56 NATO. The Patrol is slightly different from the standard 556 model with its short polymer handguards and fore-end. Also, it has a gas operating system instead of a gas piston driven operating system. The propellant gases are caught in a port then travel through a tube, the tube aims towards another tube in the bolt, which catches the gas. The gas pushes the bolt back in turn cycles the action.
Features on the Patrol include a cold hammer forged barrel, so a machine carefully cut the grooves in the bore. This process produces durable rifling. Its stock is collapsible for storage, but also adjustable for length. It has Picatinny rail for easy mounting of optics or accessories. It has a rotary diopter rear sight, which provides four sight stations: CQB, 100m, 200m and 300m, that’s adjustable for elevation and windage.
Sig Sauer recommends the Classic for law enforcement and responsible civilians.