July 2014

Duty Rifles: SIG’s 516 Patrol, M400, and 556 SWAT Patrol

There are so many brands of AR builds available, sometimes consumers settle on the nameplate then try to pick the model. In this test, we try to pick SIG Sauer’s best 5.56mm rifle.

Duty Rifles: SIG’s 516 Patrol, M400, and 556 SWAT Patrol

Fresh out of the box and still wearing their tags, here are our players: Top is the SIG 556 SWAT Patrol Rifle; middle, the SIG 516 Patrol, and at bottom, the SIG M400 Enhanced.

A Gun Tests reader gave us the idea a few years ago to not only compare firearms from different companies, but also to compare variations of a firearm inside a well-regarded company to try to select the best buy. That was our task here, to find the best semi-auto duty or self-defense rifle from a trio built by SIG Sauer, the builder of weapons of choice for many of the global military, law enforcement and commercial users. According to the company, in the USA nearly 1 in 3 law enforcement professionals use SIG firearms. “We are proud that many elite military and government forces including the U.S. Navy Seals, the Federal Air Marshals, the Department of Homeland Security and the U.S. Coast Guard carry SIG Sauer firearms,” said Ron Cohen, president and CEO.

Headquartered in Newington, New Hampshire, SIG Sauer is an ISO 9001–certified company with more than 900 employees. It is the largest member of a worldwide business group of firearms manufacturers that includes J.P. Sauer & Sohn and Blaser, Gmbh. in Germany and Swiss Arms AG in Switzerland. Where the “Sauer” part of the name comes from should be obvious; the SIG part is a little more obscure. It means Swiss Industrial Society, or Schweizerische Industrie Gesellschaft in German, thus the acronym SIG.

In its AR-15 lines, SIG makes rifles with three different operating systems. The SIG M400 Enhanced uses the direct-gas-impingement operating system. Here, we test the RM400-16B-EC model with an MSRP of $1234. The SIG 516 Patrol uses a 4-position adjustable gas valve, short-stroke-pushrod operating system. Our test gun for that line is the R516G2-16B-P designation, MSRP $1719. And, last, the SIG 556 SWAT Patrol Rifle uses a 2-position adjustable gas valve, reduced stroke, piston operating rod system. Our test sample was the R556-16B-PS-RDMSRP unit, $1399 MSRP. All the rifles were supplied by one of our Houston-based FFLs, Winkle’s Great Guns, in May 2013, so we were able to thoroughly examine them for several months. We compared operating systems, accuracy, and functionality, and we also get into the nuts and bolts of ownership, such as cleaning and assembly. So let’s see how one SIG stands up to the next.

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