The fulfilled potential of the AR-15/M16 in a 10″ pistol. One of the most tested and proven weapons systems in the world achieves ultimate refinement with the introduction of the SIG516 rifle. With its chrome-lined, phosphated, military grade barrel and adjustable, three-position gas regulator, the SIG516 incorporates all of the most desirable mechanical improvements. Add to these a free-floating quad rail forend and barrel, and you have the most advanced, versatile AR-based rifle available.