The Sig 516 is the fullfilled potential of the AR15 / M16 platform. One of the most tested and proven weapons systems in the world achieves ultimate refinement with the introduction of the SIG516 rifle. With its ambidextrous selector switch, chrome-lined, nitride-finished, military grade barrel and adjustable 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.
Features: Gas piston operating system, three-position gas regulator, 5.56 x 45mm NATO, free-floating military grade chrome lined barrel, M1913 picatinny flat top upper, 7075-T6 Aircraft grade aluminum upper & lower receiver with hard coat anodize finish.
In its general configuration, the SIG516 Patrol is a flat-top AR carbine with a 16" barrel. The 7075-T6 forged aluminum A3-style flat-top upper receiver features the traditional forward assist and shell deflector, and it mates directly with the top rail of the carbine’s free-floated, four-rail fore-end as well as a strip of Picatinny rail on the top of the gas block. This provides users an uninterrupted strip of Picatinny rail along the entire upper length of the carbine.
The fore-end is an aluminum, SIG Sauer-branded Troy Industries MRF BattleRail unit free-floated around the barrel. The chrome-lined barrel, sporting the now seemingly standard M4-style contour, is fitted with a Yankee Hill Machine Co. Phantom flash suppressor.
The lower receiver, also of forged 7075-T6, sports unique cosmetic and ergonomic enhancements. The fence around the magazine release button on the right side of the lower is more pronounced than that of a standard AR, and the front face of the magazine well is checkered for enhanced purchase by the support hand. The left side of the lower receiver has a channel forward of the bolt catch to help prevent marring of the receiver during disassembly, and the mouth of the magazine well features a generous chamfer.
Further enhancements include a Magpul MIAD modular pistol grip and a Lewis Machine & Tool SOPMOD enhanced six-position buttstock. The pistol grip is customizable to a variety of hand sizes, and the buttstock sports a padded buttplate and enlarged cheek-weld sections that double as watertight battery storage compartments.
Shortly after my visit to Exeter, my test SIG516 Patrol arrived. Once I had the rifle, I gave it a quick once-over, cleaning and lube, mounted a Leupold Mark 4 CQ/T optic and headed to the range with a sampling of .223 Rem. and 5.56x45 mm NATO ammunition.
I tested it for functioning and accuracy with three types of ammunition. The Patrol proved to be extremely pleasant to shoot, with a gentle recoil impulse. The two-stage trigger was excellent, breaking cleanly at 3 lbs. and making the SIG516 Patrol quite easy to shoot well. And shoot well it did, averaging roughly 1½" at 100 yds. overall with all three ammunition types and some Black Hills groups measuring less than 1 m.o.a. In addition, during the course of the few hundred rounds fired, I did not have a single malfunction with the carbine.
Once all was said and done, the SIG516 struck me as being exactly what SIG Sauer had intended: an enhanced AR that addresses the design’s perceived weak points while retaining all of its positive characteristics. The rifle was a pleasure to shoot, was accurate and appears to be undeniably reliable.
And, this is not the only offering planned for the series. In addition to more SIG516 5.56x45 mm NATO offerings, there are plans to introduce a variant in 7.62x51 mm NATO as well.
In my opinion, the SIG516 and its subsequent siblings portend great things for the future of the long-lived AR-style rifle, combining American know-how with precision European engineering—all in a tough and reliable package." By Michael Humphries, American Rifleman magazine, 1/15/2010