The Sig Sauer Sig 516 Basic Patrol Model is a semi-automatic tactical rifle chambered in 5.56 NATO. The Basic is an AR15-style rifle and has a gas-operated piston driven system, which functions by the propellant gases cycling back through a tube located near the muzzle and then it’s directed onto a piston to drive the bolt back. And, it’s made of a lightweight aircraft grade alloy putting its weight at 6.5 pounds.
The BPM has, like its name implies, standard Sig 516 features including a military grade barrel and trigger. The barrel is also free-floating, which means it doesn’t touch the stock. The free-floating prevents the barrel from pushing against the stock when it heats and swells. The barrel also has a corrosion resistant chrome lined bore. And, although the Sig 516 doesn’t have any sights it does have a Picatinny rail for easy mounting of optics and accessories.