May 19, 2009

Ruger Introduces SR-556 Autoloading Rifle

SOUTHPORT, Conn. -- Sturm, Ruger's new SR-556 autoloading rifle is a two-stage piston driven rifle that the company claims runs cleaner, cooler, and is easier to maintain than gas driven rifles. Chambered in 5.56mm NATO, the Ruger SR-556 also fires .223 Rem. ammunition.

The patent pending two-stage piston driven operating system in the Ruger SR-556 provides a power delivery stroke to the action and vents combustion residue out of the bottom of the gas block. The four-position adjustable gas regulator allows the operator to tune the rifle to specific ammunition and rifle conditions.

Comes with a heavy contour, 16-1/8” chrome-lined barrel forged from Mil-Spec 41V45 chrome-moly-vanadium steel, 1:9 twist rate, and an AC-556 flash suppressor.

A one-piece, ten-inch Troy Industries Quad Rail Handguard provides ample room for mounting sights, optics and accessories. Made exclusively for Ruger, this SR-556-specific handguard is pinned to the upper receiver and provides a rigid mount for the piston driven transfer rod.

The SR-556 is equipped with Troy Industries Folding BattleSights, a six-position telescoping M4-style buttstock that houses a Mil-Spec buffer and spring, Hogue Monogrip pistol grip, and three Troy Industries Rail Covers.

The barrel and gas block are chrome lined, while the bolt, bolt carrier, and extractor are chrome plated. The piston driven transfer rod is electroless nickel/Teflon coated. The flash hider and the exterior of the barrel, gas block, and regulator are manganese phosphate coated. All aluminum parts are Mil-Spec hard coat anodized. The SR-556 is supplied with three, thirty-round Magpul PMAG magazines.

The flat top upper receiver and barrel assembly is specific to the Ruger SR-556. The standard lower receiver is built with Mil-Spec components, including a single stage trigger. The lower receiver is compatible with AR-style magazines, grips, buttstocks, and fire control components.

The 7.9-pound (without magazine) Ruger SR-556 autoloading rifle is shipped in a padded carry case with hook-and-loop fasteners and internal magazine pockets.

MSRP is $1,995.

For more information on the Ruger SR-556 autoloading rifle, visit the SR-556 microsite at

Click here to see the SR-556 Spec Sheet

Comments (19)

I keep reading about the 6.5 Creedmoor round as a decent round between the two NATO rounds. Anybody shot the AR in this caliber that ISN'T paid by gun companies to write reviews?

Posted by: XDM_Niner | October 23, 2009 10:02 AM    Report this comment

223 OR SOMETHING BIGGER? HMMMM Bigger is better, 308, 30-06, 6mm. It is amazing to me that people seem so enamured with the 223, since its inception our military personel who have had to use it(not those who planned it) have been asking for some thing larger. And in our current wars it has show to be less adequate for stopping power and penetration ability. I think a 300 savage would make a great round but I think REM just came out with its balistic twin in thier AR line. Its also interesting that many states do not allow .22 calibers of any type for big game.

Posted by: JHMAN | May 30, 2009 12:50 PM    Report this comment

Bob J, you are correct, the fluid driving nearly all small arms systems is gas, acting on a piston. In the case of the M16, this piston is actually the bolt carrier itself. The advantage of this is reduced weight, since the gas tube is lightweight and has a very small diameter, and there is no separate piston or op rod assembly. The disadvantages are that all of the byproducts of partial combustion are carried into the receiver itself, with carbon (soot) plating out on the bolt, bolt carrier, and the firing mechanism internals, and dumping added heat in where it evaporates the lubricants. In the other automatics, the gas tube is much larger & heavier, is attached to a gas block on the barrel, and a piston/op rod assembly connects the operating fluid to the bolt/bolt carrier. Gas is dumped from the gas tube to atmosphere instead of the receiver internals, eliminating the dirt and heat disadvantages, but adding weight to the weapon. Hope that helps. - Gaviota

Posted by: Lee W | May 22, 2009 1:31 PM    Report this comment

Being a bit long in the tooth, and not well acquainted with much beyond the two M-1's that I knew in Korea, I realize that today's "black" magic is greatly advanced. But I can't understand how a piston driven device can be better than one that is gas driven. My old fashoned physics and mechanics, learned in Engineering, claimed that a piston had to be driven by a fluid. That fluid could be a gas or a liquid, but I've never heard of a liquid being associated with internal or external ballistics. Therefor, what drives the piston other than gas?
Bob J., OH

Posted by: Robert J | May 22, 2009 9:39 AM    Report this comment

I guess I forgot to say that after some well placed 158 gr hp 357mag from my 2 3/4 in ruger they are not around to complain about not have thier rights read to them. what can I say?

Posted by: bear1 | May 21, 2009 7:53 PM    Report this comment

Hot Damn! I want Bear on my side that's for sure!! And Welcome Home To You Too! Sorry to hear about the pin heads that got you by not wanting to work for an honest living. And I hope that they received what was comming to them! And if they didn't...God WILL have the last word and it will be good!

I do carry a .45 ACP Para PX745E SSP most of the time and back up is the S&W Night Guard 8 round .357 snubby. Gotta love that 158 grain JHP times 8! And yes...I can damn sure hit what I'm aiming at with either one. Just hope I can find some reloading components and/or ammo for them soon!

In God We Trust....

Posted by: Geometric1 | May 21, 2009 7:43 PM    Report this comment

and by the way God Bless America And Our Troops Past Present and Future

Posted by: bear1 | May 21, 2009 5:10 PM    Report this comment

Geometric1, first off I would like to say Welcome Home Bro, and like you I got hit from some ricocheting 00 buck in the lower legs, and yes I said OUCH that SMARTS, but it happened after I got home, It came from some (Blanking) gang bangers trying to rob a store. Now as for Long range I like eather 30-06, or the M14 backed up with a 357mag or 45. I agree that 223 has its place also and so does the 9mm. for close in work I like a good old 12 ga with 3in mag 00 buck with 357mag or 45 back up, and for hand to hand the 45 and a good old fashion long bladed Bowie Knife that is razor sharp dose the job real good.

Posted by: bear1 | May 21, 2009 5:09 PM    Report this comment

Thanks Robert R...
That's it...well you know what they say...the mind is the first to go for old farts like me!!

But my wife would beg to differ??!! LOL!!

And I agree... you must be able to find the target with what ever your firing. Thank the Lord I'm still in pretty good shape and my eyes are still sharp also. Now if we could all find the ammo we need to stay proficient with our weapons of choice...but that's a whole new discussion...

In God We Trust....

Posted by: Geometric1 | May 21, 2009 3:01 PM    Report this comment


It was Albert Einstein who said it. The quote is that World War III will be fought with nuclear weapons and World War IV with sticks and rocks.

So far as 30-06 vs .223, the important thing I think we can all agree upon is that the most important thing is that you can handle what you use well enough to hit what you're aiming at.

Posted by: Robert R | May 21, 2009 2:29 PM    Report this comment

Tim C...I thank you for the kind words. When we arrived back home...not many folks liked who we were and what we came home from. It is an honor to serve one's country.

About your question...M-14 good choice...I carried one that I just happened to find. But then they (the Brass) just crammed the M-16 chambered in .222 down everones throat. An AR in .300 Savage...would love to see one! But if you have the green to throw down on an AR-10...(Armalite makes one in .338 Federal and .308) I think once you wrap your trigger finger around one you will be pleasantly surprised.

And Lee W....7.62X51 NATO...never have I seen anyone or anything get up (right away anyway) after the deployment and on target of that round! LOL!!

And if you ever find yourself in need of shooting bad guys in a truck I recommend 12 Ga. 3 in. magnum 00 buck followed by your "Wing-Mans" deployment of a 30MM RPG!!! LOL!!!

Kindest Regards........

In God We Trust........

Posted by: Geometric1 | May 21, 2009 1:29 PM    Report this comment

Geometric -
I also own a Bushmaster M4 and a Mini-14, and I've seen what they can do. For light use, policing and home defense, they're fine. I live in a rural area, though, and if I have to shoot at a bad guy, say, in a truck, for example, I'm thinking the 7.62 is a better choice for heavy-duty work than a 5.56. My belief is that the 7.62 NATO can do everything that the 5.56 NATO can do, but the reverse is not true. If the SHTF, I suspect that at sometime in the fight I'm going to need penetration, and the .30-06/.308 are proven fight-stoppers. The 5.56 just doesn't have physics on it's side.

Posted by: Lee W | May 21, 2009 12:28 PM    Report this comment

Well, thanks for your service, GEO. I highly appreciate you for that, and my family does also. I am very glad the Demon Worshipper was not a good shot. Since you have been under arms for service, what do you personaaly think about a m-14 type rifle (or even ar-10)in 300 savage ?? I would appreciate your thoughts.

Posted by: Tim C | May 21, 2009 12:22 PM    Report this comment

Actually, Geometric, I have, and I have seen what they won't do also. Make no mistake, I don't want to be shot with a .223 12 times, but I don't wanna be shot with a 30-06 once, either. i PREFER the 30-06 because it was my first adolescent "big gun" and what it has done for me, personally. Same for the .45. I don't love it because Jeff Cooper did, I love it because of what it has done for me. And, what I have seen the 40 and 9mm fail to do. I do not believe we ought to write letters to the people killed by 40's and 9's telling them they can rise up, they were shot with a bad caliber, BUT IF, and I repeat IF I have a choice, the 30-06 and 45 will be my prefered weapons. (However, failing a choice, a broken baby bottle or a rock will do me in a pinch). If you are comfortable with a 223, by all means, use it and be proficient with it. It will kill also. And it is a well thought out weapon that is a light field ops rifle (I would prefer the original chambering). But I am old 55+ going on 19 and not as malleable in my choices as I was in past days. Lets just hope we can outlast Muslim oppression long enough Not to have to use our choices.

Posted by: Tim C | May 21, 2009 10:54 AM    Report this comment

Guess you guys have never seen what a .223/5.56X45 can do to someone or something??!! And I hope you never have to...
62 grain FMJ boat tail M855-SS109 rounds do terrible damage at 200 yds or less. 55 to 75 grain HP rounds at that same distance create massive wound cavities for such a small projectile most times. I own 2, a Stag AR and a Ruger mini 14 and both are pretty tricked out. I would not hesitate to employ either one in close combat if the poop ever hit the fan! But that is the key...different employment of weapons for different combat situations. I also own an AR that is chambered in .308 with a 24in. barrel...GREAT for those 600 to 800 yard shots!!

In God We Trust......

Posted by: Geometric1 | May 21, 2009 10:30 AM    Report this comment

Wonder why no one has ever made a semi-auto battle weapon with .300 Savage chambering ?? Just musing.

Posted by: Tim C | May 21, 2009 9:45 AM    Report this comment

Wonder why no one has ever made a semi-auto battle weapon with .300 Savage chambering ?? Just musing.

Posted by: Tim C | May 21, 2009 9:45 AM    Report this comment

The HK91 is a fine rifle, Gaviota, and I agree with you gbout the caliber. BUT, if you really want an AR-15 type rifle, this one seems to have all the magic buttons and bells. I have several battle rifles, but I am most happy with my Springfield M1 Garand. If things go to hell, I be carrying it and my 45 Champion Operator. I'll at least feel safer than I would with a 223 and a 9mm.

Posted by: Tim C | May 21, 2009 9:43 AM    Report this comment

I think I'll just stick with my FAL, HK91, and VEPR AK. All are massively overbuilt, durable, reliable, accurate, and not burdened with that miserable chipmunky caliber.


Posted by: Lee W | May 19, 2009 6:04 PM    Report this comment

Add your comments ...

New to Gun Tests? Register for Free!

Already Registered? Log In