Sig Sauer 516 Patrol Rifle Review – An Excellent Piston-Driven AR-15


Sig Sauer 516 Patrol Review


As with all AR-15s, this is a very reliable rifle, however, it is my personal belief that piston operated systems are even more reliable.



The rifle shoots very reliably, thanks to the excellent ergonomics, quality barrel, and decent adjustable trigger.



Due to the upgrades already in place, this is a comfortable rifle. I love the stock that Sig put on this rifle.



Looks like any other AR-15.



The options are endless.

Bang for your Buck

Bang for your Buck

This is a very pricey rifle.

What we like

  • Piston operated. Very high quality. It makes the rifle slightly more reliable, but also saves you a ton of time on maintenance. The rifle will stay clean and cool for way longer.
  • Comfortable. The ergonomics are excellent.
  • Accurate. Due to the ergonomics, barrel, and trigger, I found that this rifle shoots very accurately. Free float barrels make a huge difference. I shot this rifle out to 400 yards with relative ease.
  • What we don't like

  • Expensive. Most piston operated rifles are pretty expensive. This one is no different.
  • Picatinny rails. They’re outdated.
  • Not long ago I got really interested in a Sig Sauer M400. However, upon doing a little research, I had to compare the M400 against Sig’s other AR-15, the 516 Patrol. I spent a good bit of time handling both rifles, and was fortunate enough to get to shoot both of them, so I was able to make an informed decision.

    In this article, I’ll offer all of the insights that I gathered from the Sig 516. All in all, this is a great rifle, but if you’d like to learn more about it, continue reading this article.

    What is the rifle for?

    The Sig 516 is an AR-15, so it has an endless amount of uses. My primary uses for my AR-15s are for range shooting and hog hunting, but they can fulfill so many more needs.

    The rifles are great for range shooting. Ammunition is plentiful, and it’s not that expensive. The rifle is really easy to use, and it’s a lot of fun to shoot. They are reliable, and are easy to clean when the range day is over.

    However, 5.56 NATO is a pretty decent round, so it can be used for some smaller game hunting and home defense. While my AR-15 wouldn’t be the first rifle I reached for, it’s definitely a viable option for home defense.

    Like I said, I like to use my AR-15s for hog hunting. They can also be used for other small game hunting, like coyotes and other varmint species. Some people have used AR-15s for hunting larger game as well, but I wouldn’t recommend it.


    Like we already said, the Sig 516 Patrol is a very high quality AR-15. While most AR-15s are very similar rifles, the 516 does have a couple of features that set it apart from some of the competition. We’ll mention these features throughout our breakdown.

    The rifle is a pretty standard AR-15; it’s got a 16 inch barrel, shoots 5.56 NATO, has an adjustable stock, and it looks very similar to most. However, there is one huge difference between the 516 Patrol and most AR-15s.

    Sig Sauer Patrol 516 - 1

    The Sig 516 Patrol is a piston operated system. Most AR-15s operate off of gas blowback. For those that may be unfamiliar with these different methods of firing, we’ll give a brief introduction now.

    A standard AR-15 has a gas tube towards the front of the barrel. As the gas builds up and pushes the projectile down the barrel, it will then leak into this tube and towards the rear of the rifle, which cycles the bolt. In a piston operated rifle, this gas is collected in a separate cylinder, which uses a piston to cycle the bolt. The piston operated rifles operated much cleaner, so they require less maintenance. They also operate much colder, so you can use the rifle much faster without fear of overheating.

    Another nice feature of the piston operated system of the 516 Patrol is that the gas regulator is adjustable. Whether you’re using lower pressure ammunition, or looking for a little extra kick, you can adjust the gas system to meet your needs.

    Sig Sauer Patrol 516 - 2

    In our opinion, piston operated is always an excellent choice, especially if you’re going to be doing any tactical type shooting.

    The other pros of the rifle are the accuracy and the ergonomics. The accuracy is due in large part to the free floated hammer forged barrel paired with a quality trigger. However, the ergonomics of the rifle will also add in to this. More on that later.

    The barrel is made of quality materials, and since it’s free floated, it does shoot a little bit more accurately than some of the competition. If you compare this against a bone stock AR-15, you’ll notice this one does shoot better.

    Sig Sauer Patrol 516 - 3

    There are a couple cons associated with this rifle though. Since piston operated isn’t as commonly found on AR-15s, it’s often more expensive, which is the case here. While this rifle does offer plenty of upgrades, it is an extremely expensive rifle.

    One other con is that the rifle still has the quad picatinny rail system. While picatinny rails definitely still work, it is an aging technology. It has been almost entirely replaced by newer, lighter alternatives, such as KeyMod and M-LOK.

    Safety and Reliability

    As with all AR-15s, this rifle is very safe. The safety is very intuitive and easy to get to. As long as you handle the rifle safely, you will have no issues.

    Another thing that is extremely common with AR-15s is that they are very reliable. In my opinion, the Sig 516 may be even more reliable, due to the fact that it is piston operated. Less carbon and debris will make its way onto the bolt and carrier group, so the rifle can realistically fire more reliably.

    Comfort and Shootability

    Like we mentioned before, the ergonomics of this rifle are excellent. The grip is much improved when compared to a standard AR-15 pistol grip, and the stock is excellent.

    Sig Sauer 516 Patrol Rifle

    The stock is a B5 Systems Bravo SOPMOD, which is a multi-position adjustable stock. It’s got a large, flat area, which will allow you to get a consistent cheek weld each and every shot. You’ll find that this improves your shooting significantly, as long as you are practicing the correct fundamentals.

    Another nice thing about the ergonomics of this rifle is that the charging handle and magazine release are fully ambidextrous. For our left-handed friends, this is a huge plus.

    In terms of shootability, this rifle is excellent. All AR-15s are really fun to shoot, but this one takes it to the next level. Due to the fact that it is piston operated, it’ll stay significantly cooler, and you don’t have to worry about cleaning it as much. I would still clean mine every time I shoot, personally, but you can get away with not doing that.

    Accessories and Upgrades

    There are countless things that you could upgrade about this rifle. This is one huge draw of the AR-15 platform.

    My first upgrade would be the handguard. Like I said, I’m not a fan of the picatinny rails. They are outdated, uncomfortable, and unnecessarily heavy. I would replace it with this KeyMod or this M-LOK handguard personally.

    Next, I would add on some type of foregrip. If you do replace the handguard, make sure that you get a grip that actually fits the type of guard your rifle now has. If you have the picatinny rail, I prefer an angled grip, but others prefer a vertical.

    Next, I’d get some type of optic. I like a simple red dot sight, like this one from Vortex, but maybe you prefer something with a variable zoom, like this optic from Nikon.

    Last, you probably want more than just the one magazine the rifle comes with, so check out the PMAG from Magpul.


    As you’ve seen, this is an extremely high quality rifle, although it is definitely on the expensive side. It is piston operated, which is extremely unique when compared to other AR-15s, but it’s also a great feature for the rifle. There’s a lot to like about this rifle, as long as the price doesn’t scare you off.

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