Skip to main content

Ruger AR-556 Review

Ruger_AR-556_review_FWhen Ruger announced about five years ago that it was making an AR-style rifle, the gun world went wild. That first AR-platform rifle from Ruger (called the SR-556) was a big hit, but because it was a piston gun with a retail price tag of around $2,000, plenty of shooters were reluctant to buy one. Well, now Ruger has brought out a direct impingement AR, and the MSRP is a very reasonable $749. I'll bet a lot of those guys will be ponying up their hard-earned cash for the new Ruger AR-556.

The Gas System

Obviously, the fact that Ruger is offering a direct impingement AR is big news. When the company brought out its piston-driven AR, every gun writer who thought it was a good thing wrote about the advantages of the piston system, saying things like piston systems tend to be cleaner shooting. They pointed out that with the direct impingement system unburned powder and gases are vented back into the rifle's action, which causes a lot of fouling, sends noxious gases back toward the shooter, and makes the action very hot. With the typical piston-driven system, those hot gases and unburned powder are vented out through the front of the gun.

A lot of AR aficionados think the direct impingement system is just fine. In fact, they would argue that with the direct impingement system parts tend to last quite a bit longer, as long as the gun is properly cleaned at regular intervals. They would also say that the most accurate ARs have always been direct impingement guns. And they could easily contend that direct impingement guns have softer recoil impulses, tend to be lighter in weight, and generally cost less.


I'm not taking a side in the debate. I'm merely pointing out that there are good arguments for both systems. Either way, Ruger now has ARs with both mechanisms.


The new AR-556's gas system is a mid-length system, in keeping with its carbine-length barrel (more about the barrel in moment). The milled gas block is described as an A2, F-height block. It's pinned in place, and it has multiple sling-attachment points and a bayonet lug.

The AR-556's lower receiver is a 7075-T6 aluminum forging. Its finish is Type III hard coat anodized. The trigger guard opening is enlarged.

The flat-top upper receiver is also 7075-T6 aluminum. It has the typical forward assist, dustcover, and brass deflector. The slotted top rail measures 5.5 inches long. And like the lower, the upper receiver wears a Type III hard coat anodized finish.

The bolt is 9310 alloy steel. The bolt carrier group has a staked gas key, a chrome-plated bolt carrier inside diameter, and a chrome-plated gas key inside diameter. External finish is matte black oxide.




The Barrel

The AR-556's medium-contour barrel is a cold hammer-forged 4140 chrome-moly steel tube with a 5.56 NATO chamber and M4 feedramp cuts. The barrel's diameter is 0.85 inch under the handguard, 0.75 inch under the gas block, and 0.70 inch forward of the gas block. The length is 16.1 inches, and the twist rate is 1:8.

That's going to please a lot of AR shooters because a twist of one turn in 8 inches will stabilize bullets across a wide range of weights. Everything from 35 to 77 grains should shoot pretty well in the 1:8 twist rate. Only the heaviest bullets for this caliber (e.g., 90 grains) probably will not stabilize.


The barrel's finish is matte black oxide, and its muzzle is threaded to 1/2x28. The gun comes with a flashhider that's very much like the ones on Ruger's Gunsite Scout bolt actions and Mini-14 autoloaders. It can be removed and swapped for other muzzle accessories.

The Buttstock & Grip

The buttstock is the popular M4, six-position, collapsible style. Accordingly, length of pull ranges from 10.25 to 13.5 inches. The buffer tube is mil-spec.

The pistol grip has what Ruger calls an "ergonomic improved trigger reach" grip. Circumference of the grip just below the trigger guard measures 4.60 inches, and the distance from the back of the grip to the trigger is 2.51 inches.

The Handguard

The two-piece handguard is constructed of heat-resistant glass-filled nylon in the traditional round shape. The barrel nut and delta ring are a new patent-pending design that accepts standard carbine-length handguards and uses a standard wrench. It can be swapped out for a mil-spec nut if the owner so desires.

The Trigger

The trigger on ST's sample AR-556 was good. Ruger has taken some heat in the recent past for the quality of its triggers. Complaints have centered around the triggers being excessively heavy and with lots of creep. The single-stage trigger on the AR-556 I fired for this report was pretty good. Pull weight is a little heavier than I prefer, but it was consistent. It averaged 7 pounds, 8 ounces over 10 measurements. Those values varied 12 ounces across all of those measurements.

The Sights

The AR-556 comes with sights. The rear is Ruger's own Rapid Deploy folding sight that's adjustable for windage. It has a peep-type aperture and side protection ears. The front post sight is the classic A2 style, and it's adjustable for elevation.

Shooting Results

For putting the AR-556 to a shooting test, I picked seven .223 factory loads from six manufacturers, including Australian Outback, Black Hills, Federal, Hornady, Remington, and Winchester, with bullets ranging in weight from 52 grains to 69 grains. The details are listed in the accompanying chart. Overall, the AR-556 averaged 1.79 inches for five-shot groups at 100 yards. Its three-shot overall group average was 0.94 inch. I removed the rear sight and mounted my trusty Nikon M-223 AR 1.5-6X 24mm scope with illuminated reticle in a Nikon one-piece mount for the accuracy shooting session.

Top velocities in the AR-556 came with Black Hills's 52-grain ammo and Hornady's 55-grain TAP load, averaging 2,853 fps and 2,867 fps respectively. No surprises there. What did surprise me, however, was that the most accurate bullet weight was 55 grains. I fired three different brands of 55-grain ammo, and those three loadings averaged 1.55 inches. The most accurate load (Winchester's Ballistic Silvertip) averaged 1.38 inches.

According to Ruger spokesmen, the AR-556 was extensively tested during its development, with over a quarter-million rounds expended during the final validation, endurance, and jury testing. My short time with the new direct impingement carbine, shooting more than 500 rounds for accuracy and function in one afternoon, confirms that Ruger did its due diligence with this gun. I didn't have a single malfunction, accuracy with all bullet weights I fired (from 52 to 69 grains) was very good, and trigger pull was decent. And you sure can't beat its very reasonable MSRP.

The new AR-556 features a 16.1-inch barrel with a 1:8-inch rifling twist rate, a six-position collapsible M4-style buttstock, an ergonomic pistol grip, and a glass-filled nylon handguard. It's the first model to be built at Ruger's new factory in Mayodan, North Carolina.
The new AR-556 carbine's bolt is made of 9310 alloy steel. The bolt carrier group has a staked gas key, and the exterior finish is matte black oxide while the inside is chrome plated.
The flashhider is similar to those that come on Ruger's Gunsite Scout bolt action and Mini-14 autoloader. It can be swapped out for other muzzle accessories.
The trigger is a single-stage unit. The pull weight of ST's sample averaged 7.5 pounds.
The carbine comes with an A2-style post front sight that's adjustable for elevation.
A flip-up, windage-adjustable Ruger Rapid Deploy rear sight is available with the AR-556.
One 30-round Magpul PMag polymer magazine comes with the carbine.
The best single five-shot 100-yard group came with Black Hills 52-grain Match ammunition (0.95 inch), and the carbine's overall average for seven factory loads ranging in bullet weight from 52 to 69 grains was a very respectable 1.79 inches.
The barrel nut and delta ring are a new patent-pending design that uses a standard wrench.
Reviewing the AR-556 gave the author the chance to use Caldwell's AR-15 magazine loader for easy loading.

Specifications

Performance

The trigger guard opening has been enlarged.

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Recommended Articles

See More Recommendations

Popular Videos

All About .300 Blackout

All About .300 Blackout

The .300 Blackout is here to stay, and we take some time to look at new technology surrounding this cartridge. Next, we pit subsonic rivals against each other before stretching the legs of this CQB round out to 600 yards from a short 9-inch barrel.

Hornady 6MM Creedmoor

Hornady 6MM Creedmoor

Tom Beckstrand and Neal Emery of Hornady highlight the 6MM Creedmoor ammo.

The Future Of Special Operations Small Arms

The Future Of Special Operations Small Arms

We're taking a look at what the Army's Elite Units are using for service rifles and what the future of SOCOM sniping looks like.

Black Hills Evolution of Rifle Cartridge: .308 Win. 175 Gr. Match

Black Hills Evolution of Rifle Cartridge: .308 Win. 175 Gr. Match

David Fortier talks with Jeff Hoffman of Black Hills Ammunition about the evolution of the .308 Win. 175 Gr. Match bullet.

See More Popular Videos

Trending Articles

Firing 21 different loads in Kimber's Mountain Ascent rifle proved it is a good friend to have in high places.Kimber Mountain Ascent Rifle Review Rifles

Kimber Mountain Ascent Rifle Review

Steve Gash - January 22, 2021

Firing 21 different loads in Kimber's Mountain Ascent rifle proved it is a good friend to have...

Shooting a .22 LR rifle at 300 yards is just as challenging as shooting a .300 Win. Mag. rifle at 1,000 yards.Ruger Custom Shop 10/22 Competition Rifle at 300 Yards Rifles

Ruger Custom Shop 10/22 Competition Rifle at 300 Yards

Layne Simpson - November 13, 2020

Shooting a .22 LR rifle at 300 yards is just as challenging as shooting a .300 Win. Mag. rifle...

The .30-06 Hawkeye Hunter features a 22-inch stainless-steel barrel and a satin-finished walnut stock. Magazine capacity is four rounds. It is well made, accurate, and attractive. This is a fine rifle that is light enough to tote over hill and dale but heavy enough to hold steady for precise shooting in the field.Ruger Hawkeye Hunter .30-06 Review Rifles

Ruger Hawkeye Hunter .30-06 Review

Steve Gash - August 17, 2020

The .30-06 Hawkeye Hunter features a 22-inch stainless-steel barrel and a satin-finished...

How can a shorter-barrel revolver have higher velocities than a longer-barrel semiauto pistol? Here's why.Revolver vs. Semiauto Pistol: A Ballistic Oddity Handguns

Revolver vs. Semiauto Pistol: A Ballistic Oddity

Allan Jones - May 15, 2019

How can a shorter-barrel revolver have higher velocities than a longer-barrel semiauto pistol?...

See More Trending Articles

More Rifles

Using 18 Ruger 10/22 rimfire rifles, John “Chief AJ” Huffer consecutively shot 40,060 2.5-inch wood blocks without a single miss.John “Chief AJ” Huffer — Rimfire Record-Setter Rifles

John “Chief AJ” Huffer — Rimfire Record-Setter

Joel J. Hutchcroft - October 07, 2020

Using 18 Ruger 10/22 rimfire rifles, John “Chief AJ” Huffer consecutively shot 40,060 2.5-inch...

There are plenty of good .22 rimfire rifles under $300 on the market. Here's a quick look at some of the most interesting models.Best .22 Rimfire Rifles Under $300 Rifles

Best .22 Rimfire Rifles Under $300

Payton Miller - January 11, 2021

There are plenty of good .22 rimfire rifles under $300 on the market. Here's a quick look at...

Red-dot sights may be just what the doctor ordered for lever-action fans of “a certain age.”Best Red-Dot Sights for Lever-Action Rifles Rifles

Best Red-Dot Sights for Lever-Action Rifles

Payton Miller - December 28, 2020

Red-dot sights may be just what the doctor ordered for lever-action fans of “a certain age.”

Uberti's 1885 Courteney Stalking Rifle is a classically configured hunting rifle that's equally at home in the big whitetail woods and on the African savannas.Uberti 1885 Courteney Stalking Rifle Review Rifles

Uberti 1885 Courteney Stalking Rifle Review

Joseph von Benedikt - December 14, 2020

Uberti's 1885 Courteney Stalking Rifle is a classically configured hunting rifle that's...

See More Rifles

Magazine Cover

GET THE MAGAZINE Subscribe & Save

Digital Now Included!

SUBSCRIBE NOW

Give a Gift   |   Subscriber Services

PREVIEW THIS MONTH'S ISSUE Arrow

Buy Digital Single Issues

Don't miss an issue.
Buy single digital issue for your phone or tablet.

Buy Single Digital Issue on the Shooting Times App

Other Magazines

Special Interest Magazines

See All Special Interest Magazines

GET THE NEWSLETTER Join the List and Never Miss a Thing.

Phone Icon

Get Digital Access.

All Shooting Times subscribers now have digital access to their magazine content. This means you have the option to read your magazine on most popular phones and tablets.

To get started, click the link below to visit mymagnow.com and learn how to access your digital magazine.

Get Digital Access

Not a Subscriber?
Subscribe Now