Ruger's AR-556 Pistol

In 1865 Charles Dodgson, a conservative Christian working as a mathematician at Christ Church College, Oxford, writing under the pseudonym Lewis Carroll, penned “Alice’s Adventures in Wonderland”. Dodgson’s intent was to have published a satirical criticism of abstract mathematicians of the day. The well known setting of Alice and the caterpillar, contrary to Grace Slick’s hijacking of Dodgson’s work, is actually a reference to Augustus De Morgan’s symbolic algebra’s break with traditional algebra, arithmetic and geometry 1). Therefore, we can only conclude that reinterpretation of an idea by anyone other than the originator can only be deemed to be Bad! Bad! Bad!. Not really…

If Dodgson’s work had been viewed as its original concept and intent, it would have been read by only Dodgson and six other stodgy mathematicians, before languishing beneath the cobwebs in the damp basement of the Christ Church College library. Instead, interpreted, reinterpreted and even misinterpreted by its readers, “Alice’s Adventures in Wonderland” has brought an infinite amount of entertainment and enjoyment to millions. So we can therefore conclude that ignoring the creator’s intent and reinventing its purpose through the imagination of many is always a good idea. Good! Good! Good!  Not really… please see John Milton’s Paradise Lost for a different possible outcome 2).

I don’t think it is meant solely for clearing a closet full of zombies…

The Ruger AR-556 Pistol manual and collateral material do an excellent job of defining what the AR-556 Pistol is, but leaves it up to the collective experience and imagination of its customers to define and extract the pistol’s potential. In a world of knee jerk, meme opinion and internet sage cliches, that could be a dangerous tactic. So it seemed like a good idea to stay out of social media, take the pistol out of its box and view the AR-556 Pistol from a different perspective. Rather than an AR-15 disadvantaged by a short barrel and an arm brace in place of a buttstock, it seemed only fair to compare this pistol’s performance and capability to other pistols. One mushroom makes it a rifle with a diminutive barrel, the other mushroom makes it a relatively long barreled handgun.

Dissolve followed by flashback

In the early 70s, when I was sporting an Omar Sharif mustache, woolly sideburns, spiffy polyester blue slacks and an open long collar paisley shirt, I purchased a Thompson Center Contender with a 10″ barrel, chambered for the 222 Remington. I would post a picture of myself with the T/C, but all of the photos of me during that era were destroyed in a mysterious trash can fire.

Ruger AR-556 Pistol

Manufacturer Sturm, Ruger & Co.
Point of Manufacture Mayodan, NC
Model# 8570
Caliber 5.56 NATO / 223 Remington
Mag Capacity 30 Round Magpul PMag
Barrel Length 10.5″ 4140 CM
Muzzle Threads
1/2″-28
Rifling 1:8″
Weight 6.2 Lbs
Overall Length 25.3″ – 27.9″
Height
7.2″
Stabilizing Brace
SB Tactical SBA3
Receivers 7075-T6 Aluminum Forging
Receiver Finish Type III Hard Coat Anodized
Barrel & Gas Block Matte Black Oxide
Handguard 9″ Free Float + M-Lok Slots
Accessory Mount Picatinny Rail+M-Lok
Trigger Pull 7 Lbs. 2 Oz. Single Stage
Safety Rotating
MSRP $899

In the basement of our home, a large piece of 3/8″ thick steel, angled over at 45°, positioned over a 6″ deep box of sand, routinely served as a backstop for practice shooting with a 45 Auto and FMJ ammo. The bullets barely left a mark on the steel before fragmenting and collecting in the sand. However, the first 55 grain hollow point from the Contender blew a hole through the steel plate and took a chunk out of the backing cinder block basement wall.The Contender was more than enough to drop deer, hogs and large and small varmints out to 150 yards, so successfully that I still own the pistol today.

What improvements would make a Contender better for hunting and expand its usefulness into rural security? A more powerful cartridge, multi shot capability, semi automatic operation, and better stock geometry to make accurate shooting at a distance an easier proposition. That last sentence describes the Ruger AR-556 Pistol. Based on its function, chronograph results and perforated targets and life experience, if the Ruger AR-556 Pistol is a close quarter short range defender, that limitation resides solely with the shooter or the chosen application. A little further on we’ll review recorded performance with subsonic and supersonic ammunition, objectively measured.

But first, some poking around…

Putting a butt stock on firearm with a barrel length less than 16″ will make it an NFA firearm, which requires special licensing, payment of taxes, fingerprints and other assorted and sundry documentation. The Ruger AR-556 Pistol has a stabilizing brace in place of a buttstock. It is meant to be held like a pistol, not shouldered like a rifle.

The SB Tactical® SBA3™ Pistol Stabilizing Brace®m a product of SB Tactical. The brace worked well in the collapsed position, it grips like a boa constrictor, with the red dot and it worked well with the pistol scope with forearm support. It does not work with a rifle scope… unless the shooter pulls the brace full back and supports it at his shoulder and moves his head forward to a typical eye relief distance of a couple of inches. The issue of this use of a brace in this manner, in concert with the pistol’s short barrel, is approved as covered in an ATF opinion letter.

Take down, no surprise here, is just like any other well made AR. The upper receiver is forged from aircraft grade 7075-T6 aluminum, complete with forward assist and dust cover. The bolt is machined from 9310 steel, shot peened and pressure tested, the bolt key is staked to prevent loosening. The bolt carrier and bolt key are chrome plated internally, the bolt carrier is black oxide finished for corrosion resistance.

Two fasteners at the bottom side of the handguard are loosened and the guard is pulled forward for removal. The gas system… hard to see the silver tube against the white background, is carbine length to facilitate reliable operation. The 9″ handguard has Magpul M-Lock accessory attachment slots at 3, 6 and 9 o:clock positions.

The 10.5″ barrel us made from 4140 chrome-moly steel barrel through a cold hammer forged process. The 1:8″ twist rate, 5 groove right hand rifling stabilizes bullet weights from 35 to 77 grains. The Ruger proprietary chamber accommodates both 5.56 NATO and .223 Rem. ammunition, including the higher pressure of the 5.56 NATO.

M4 feed ramps enhance feed reliability. The barrel has a durable matte black oxide finish for corrosion resistance and to hide any ninja moves planned. No, not really… that ninja thing. Not to get lost to my nonsense, the Ruger AR-556 Pistol is a quality product that will stand up to a lot of use even in less than pristine environments.

Configure to personal preference and applications

The Ruger AR-556 is not supplied with a sight system, however, it presents many options for a customer to mount what they deem appropriate. Initially, not knowing how much reach the pistol would provide, a red dot sight was mounted. From the Ruger Shop, a UTG Leapers 3.9″ Red/Green Circle Dot Reflex Sight SCP-RDM39CDQ with a 4 MIL dot and 58 MOA halo. Powered by two AG5 batteries, each color selector acts as an on/off switch as well as color and illumination brightness selector. Left idle, the sight will power down in one hour. Windage and elevation adjustments are in 1 MOA increments and can be locked in position after adjustment is set.

The red dot was set up for 50 yards, the first distance shot. Not going GI Joe, but really fond of my hearing, an Advanced Armament SR-5 silencer on a 90 Tooth Ratchet Taper fast attach system was installed. The overall length of the AR-556 was increased a net 6″ for an overall length of 31.3″.

Shooting at a longer distance, the red dot was removed and both a rifle scope and pistol scope were tried. The handgun scope, shooting from a rest, kept the configuration legal and it felt a lot like shooting any other scoped centerfire pistol… except for that 30 round mag. The red dot was the best, in my estimation, for general use. It is too fast and too compact to set aside on distances out to 100 yards and more with a better shooter.

Handloading with John Prine… I need to de-focus to refocus

Listening to John Prine is good background to a handloading session. The John Prine and Iris Dement duets are unique and very entertaining. The same could be said for John Prine and Steve Goodman. On that note, a little John Prine and Steve Goodman “You Never Even Called Me By My Name”… and I’ll get back to work if I can find those dies.

Two types of bullets were handloaded, each with a supersonic and subsonic charges. The interest was in getting a sense for velocity produced from the 10.5″ barrel, an opportunity to examine exterior ballistics and a ballpark sense of accuracy. The Hornady 75 grain hollow point boat tail is a consistently good performer and Remington 55 grain PSP bulk bullets are good performers and inexpensive.

Warning: Bullet selections are specific, and loads are not valid with substitutions of different bullets of the same weight. Variations in bullet length will alter net case capacity,  pressure and velocity. Primer selection is specific and primer types are not interchangeable. These are maximum loads in my firearms and may be excessive in others. All loads should be reduced by 5% as a starting point for development where cartridges have greater than 40 grains in capacity and 10% for cartridges with less than 40 grain capacity following safe handloading practices as represented in established mainstream reloading manuals. Presentation of these loads does not constitute a solicitation for their use, nor a recommendation.

5.56 NATO
Firearm Ruger AR-556 Pistol
Barrel Length 10.5″
Min – Max Case Length 1.760″ +0.0″/-0.030″
Min – Max Cartridge Overall Length 2.125″ – 2.260″
Primer CCI 400 – Small Rifle
Bullet Diameter 0.2245″ +0.0″/-0.003″
Reloading Dies RCBS FL
Loaded up to and below 62,366 psi
Bullet Type  Bullet Weight
Grains
Net H2O
Grains
Capacity
COL” Powder Type Powder Charge
Grains
Muzzle Velocity
fps
Muzzle Energy
ft/lbs
100 Yard
3 Shot
Group”
Remington PSP 55 26.1 2.190 Trail Boss 4.0 1033 130 1.1
Remington PSP 55 26.1 2.190 Re 10x 23.5 2644 854 1.4
Remington PSP 55
26.1
2.190
Power Pro Varmint 25.0
2631
846
1.0
Remington PSP 55
26.1
2.190
Norma 201 25.5 2625 842 1.2
Hornady BTHP 75 24.3 2.250 Trail Boss 5.0 1092 199 2.0
Hornady BTHP 75 24.3 2.250 Power Pro Varmint 24.0 2518 1056 1.6
Hornady BTHP 75
24.3
2.250
BL-C(2)
25.0
2493
1035
1.4
Hornady BTHP 75
24.3
2.250
CFE 223 26.0 2505 1045 1.6

Yes, velocity compared to a 16″ or 26″ rifle barrel is down a bit, something to the tune of 400 fps+/- and accuracy is plus MOA. But for a pistol, the performance is stellar and definitely illustrates why the AR-556 Pistol is more than a close-in firearm. Looking at this in another way… from the Real Guns Ballistic Calculator:

Best Zero Results 55 Grain
Near-Zero – Yards 24 Mid Range – Yards 111
Far-Zero – Yards 189 Max Ordinate – Inches +2.5
Point Blank – Yards 204
Best Zero : Range 0 – 300 yards 55 Grain
Yards 0 50 100 150 200 250 300
Velocity – fps 2644 2426 2219 2024 1839 1664 1506
Energy – ft.-lbs. 854 719 601 500 413 338 277
Momentum – lbs-sec 21 19 17 16 14 13 12
Path – in. -1.50 1.21 2.44 1.90 -0.76 -6.01 -14.40
Drift – in. 0.00 0.00 0.00 0.00 0.00 0.00 0.00
Time Of Flight – sec. 0.00 0.06 0.12 0.19 0.27 0.36 0.45

Zeroed at 189 yards, the 55 grain Remington PSP has a point blank range of 204 yards, never rising above or falling below line of sight by than 2.5″ over that entire distance. At that range the bullet is traveling well over supersonic and still pulling kinetic energy that is about the muzzle energy of a 357 Magnum revolver. Better yet, the 75 grain Hornady, because of its better ballistic coefficient, has a slightly longer 213 yard point blank range, it is traveling above 2000 fps at 200 yards and with 737 ft-lbs of energy.

So why the subsonic loads? People like to shoot them, although I can’t see a practical purpose for them. Point blank range is about half of supersonic, velocity starts off low and obviously doesn’t get better and even muzzle energy is below 200 ft-lbs. That said, there are always special applications or situation, but none come to mind.

Supersonic ammo cycled without a problem. The 75 grain Hornady load up in standard magazines and cycled without a problem. All of the subsonic loads were manually cycled. It was like trying to get the 17-357 RG to cycle a modified SIG; low velocity, low mass, low gas volume… putt, putt, putt. There is a 300 Blackout version of the Ruger AR-556 and that is where I would focus my attention for subsonic if that was my interests.

So what do I do with it?

Every once in a while, I will look at a thread regarding home security. Sometimes they begin well, but it doesn’t take long before they are reduced to drivel. So many theories and approaches, concerns and distractions… with comments that sound like people are running an operation inside of enemy territory. And there is always a group that knows all the rules of selection, according to the last trend that got social media traction. Fortunately, life’s events don’t always go according to constructed, far fetched scenarios. How to use the Ruger AR-556 Pistol? Anyway you choose.

For me, I’d mount a red dot, a decent sling and keep the stabilizer pushed in for most circumstances, knowing I could extend the stabilizer to facilitate longer range use. I’d load it up with 70 something grain soft point bullets, to 5.56 NATO pressure levels, and use it the minute I had to step out of my home or shop to investigate a problem situation. I would chose it over an AR-15 carbine or rifle because of its compact form and satisfactory ballistics over a useful range.

If there is any finessing to be done? Not a necessity to fix, but the factory trigger was on the heavy side and with a bit of creep. It’s a clean up job on the existing trigger or an easy change to the Ruger® Elite 452® AR-Triggers or similar?

 

1) Bayley, M. (2009). ‘Alice’s Adventures in Algebra: Wonderland Solved’, New Scientist, Issue 2739.
2) John Milton (1667). Paradise Lost

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