On Target Review: Sig Sauer 516 Upper

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By Rob Kay and RN Price

SIG 516 upper–a real workhorse with a great pedigree

Although SIG Sauer is better known in our country as the manufacturer of high quality semi-auto pistols, making rifles is not exactly a new development for this Swiss-German icon. Established in 1853 as a wagon factory above the storied Rheinfall (Rhine Falls), the savvy founders opted to enter a competition to develop a rifle for the Swiss Army.


It was a fateful decision.

Four years later, the Swiss government awarded the humble wagon factory with an order for 30,000 of their muzzle loading Prelaz-Burnand rifles. At that point the owners decided to change the name of the company to the Swiss Industrial Company or Schweizerische Industrie-Gesellschaft, aka SIG.

Fast forward to 1985 and SIG Sauer had set up shop in the US. By 1990, the company began manufacturing handguns in Exeter, New Hampshire.

Knowing a good platform when they saw one, the company started designing and building AR 15-style rifles with gas piston operating systems. We were always under the impression that with their Swiss-German engineering savoir faire, the SIG rifles would have been solely designed in Europe. We were wrong. According to the company Rifle Product Manager, Jarrod McDevitt, both US and European engineering go into the ARs.

Quality of the finish is first class and very business-like

Unlike many of the smaller manufacturers, SIG manufactures all their major components such as receivers, barrels, etc in house.

Gas piston AR rifles, once shunned by some as being undependable and inaccurate compared to the original so-called “Direct gas Impingement” (aka DI), design, are clearly on the ascendant. There are a couple of reasons but the one we like to talk about is their ease of maintenance. Because the expended gas and fouling from the spent cartridge isn’t piped directly into the receiver on a piston gun, there’s no carbon build up on the bolt or carrier, and no combustion debris splattered all over the guts of the receiver. The only additional parts you have to clean are the gas plug, cylinder, and piston. We can assure you, it’s much easier to attend to a piston system after a range session than a DI system.

As many DI purists are beginning to learn, the newest generation of gas piston guns are neither undependable nor inaccurate. Unlike the DI guns which generally adhere to a “milspec” standard, each company that manufactures a piston gun engineers their own technology.  In other words there is no standard gas piston design.

The upshot?  If you choose a manufacturer, you might be well advised to consider a company that’s not going to go bust within the next 6 months.

Enter the SIG 516 Patrol

The first generation of the SIG 516 was introduced in 2010. Ours is of the second generation (we’ll discuss the differences of the “Gen 2” further down the column). The upper has a 16” free-floating military grade chrome lined “phosphated” barrel. The receiver is manufactured from 7075-T6 Aircraft grade aluminum, with a charcoal black, anodized surface. The quality of the finish is first class and very business-like. No zombie icons or gratuitous flourishes.

True to the pedigree of the rifle, the aesthetic is clearly a cross between Yankee pragmatism and Teutonic engineering.

Other features include a four-position gas regulator and a M1913 Picatinny flat top upper. The website says that the gun comes with “flip-up iron sights” but our upper was bare. We added Diamondhead D-45 “swing sights”. (More on them in a separate story).

Gen 2 has undergone several improvements from the first iteration.

The Gen 2 model’s 4-position gas regulator has been redesigned for easier removal (for cleaning).

SIG has added an “enhanced” proprietary barrel attachment system with a redesigned barrel nut.

What’s the point?

The newly designed attachment apparatus eliminates need to realign barrel nut with the piston or gas tube. They also tweaked the gas piston, or rather how you remove from the upper. Used to be (Gen 1) you had to unscrew it—it was threaded. Now, all you need to do is depress the detent button, and (hand) turn it counter clockwise. It then pops right out. Unless of course, it doesn’t. If the carbon build up gets a little too thick you’ll need some pliers. The upper can be field stripped for cleaning with no tools.


This is a good segue into our favorite characteristic about piston guns. Cleaning is really so much less labor intensive than the DI system. As we alluded to before, gas laden junk isn’t piped into the receiver so the insides stay a helluva lot cleaner, longer. Thus the intensive cleaning will be centered inside the barrel and the gas piston assembly. The bolt carrier and receiver internals don’t get as dirty as quickly, and may just need a quick wipe after a shooting session.


SIG Sauer pride themselves on their dependability and to make sure you don’t forget it (actually to rub in your face)  they produced a rather memorable video that’s painfully graphic in their variety torture tests which include full immersion in water, mud and sand. (Naturally the rifle performed flawlessly in the movie). We didn’t try this at home with the upper that SIG kindly loaned us but we got the message.

Our stand out impression of this upper after putting about 500 rounds of various ammo (including handloads) was not what it could do.

It’s what it didn’t do.

Cleaning the BCG was pretty much a wipe down instead of a “decrusting”. What a concept…

It didn’t jam or misfeed once. Not once.


Accuracy was more than sufficient. The caveat is that you really need a to use ammunition loaded with a heavier bullet to get the best groups. The barrel has a 1:7 twist which is best for stabilizing bullets in the 69-77gn range. Our groups got as good as 1” at 100 yards with handloads built around 75 grain match bullets. Whether this was a fluke, I can’t say.

What I can say is that the particular upper we had didn’t do as well with 55 gn bullets. We’re talking 2-3” groups at best. Not wanting to be unjustly critical of this upper, we borrowed another 516 Gen 2 upper and put a few hundred rounds through it. It did very well with the lighter bullets—our best was 1.5” groups at 100 yards with the 55 gn  bullets. We were even able to whack a 12” gong at 440 yards. That’s not easy to do with a .223 carbine on the windy slopes of Kokohead Crater.

So go figure?

We’ve gotten better groups with other uppers, particularly those employing Wylde chambering, but in all fairness this upper is not designed to be employed as the component of a match rifle. It’s meant to be used in a duty gun that will function when the chips are down. (If you’re  more concerned with accuracy, SIG makes a higher-end “DMR” model).


This is a quality product. Well designed, nicely finished and superbly engineered, it’s also very reliable. As alluded to, we had the chance to fire two Gen 2’s and didn’t have a single jam with either of them. With a big bullet you’re guaranteed to have all the accuracy you will want. With a smaller bullet, all the accuracy you need.

Photos courtesy of On Target staff.

Questions?  Comments?  Contact us at ontargethawaii@gmail.com

Rob Kay writes about firearms for Hawaii Reporter and is the author of How to Buy an AK-47.
Read more of Rob’s articles on OnTargetHawaii.com





  1. Mention Heavy Overall Weight and Likewise Heavy Triggers. The Aesthetically Curious Front Gas Block gets Hot Fast: Be Aware(!) Quad Rails apparently "so yesterday" and the DI vs. Piston debate getting old too. SHTF and Battle musings sell a lot of Guns: The Reliability, The Amount of Effort to Make a Weapon Fail, Rate of Failures and Accuracy rather overblown with paper n' steel warrior's angst-driven meditations. But it is Fun, no? SIG still offering DI guns for about $400 less; the funds of which could be expended for trigger swap or practice ammo. The featured weapon has merit and value for money, not to mention a good reputation. There are U.S. made weapons that for almost half the cost will get you thru your nightmares just fine however. Cleaning and Maintenance a Given especially in autos…no biggie eh?

    Thanks for a nice feature! Aloha! Gary.

  2. Hey Gary,

    Thanks for the comments! Sorry I didn't get to this earlier. Let's to hear from you again.


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