http://vuurwapenblog.com/2010/07/21/ruger-sr-556/

http://vuurwapenblog.com/2010/07/23/ruger-sr-556-range-update/

––––––––––––––––––––––––––––––––––––––-

I'm going to be honest. I would probably never purchase this rifle. It just has too many drawbacks, in my mind - it's heavy, it has an extreme forward CG, it's not fully end user serviceable, you're effectively limited to one rail system, and it's a gas piston/op-rod weapon. These are the items that came to mind when I first examined an SR-556 at the 2009 NRA show in Phoenix.

Evidently, Ruger heard enough about weight from customers that they recently introduced the SR556C model, which has a shorter, fluted barrel, resulting in a significant weight savings. Unfortunately, it also has an integral muzzle device; this severely limits the options of the end user, and it's nothing that I'd want to deal with. Some may be perfectly happy with it - more power to them. It's just something that makes me scratch my head and wonder, "What were they thinking?" It's good that they listened to consumer demand regarding weight, though.

You're probably asking yourself why I bothered with this rifle, given the previous few paragraphs. Well, although I had shot one, I had not owned one, and I figured that it would make for an interesting comparison with the POF P-415 I have for T&E. In addition, a major reason for acquiring it (in a trade, I should add) was to determine the center of gravity of the weapon, and add it to my weight and balance calculators. I'll get to that later. First, an overview of the weapon.

Overview



The SR-556 includes a number of nice extras. A decent soft case, three Magpul PMags, the aforementioned Troy rail, Ruger marked Troy front and rear folding iron sights, three rail covers, and a Hogue grip are the items that immediately come to mind.



The supplied stock is modeled after the Colt M4 stock body, with minor differences in construction that cause it to weigh approximately 1 ounce more than the M4 stock. I found it wholly inadequate for the purposes of balancing out the muzzle-heavy weapon, so I immediately installed a Vltor EMod. Any decent "fighting rifle" will have a white light, so on went a spare Surefire G2 with drop in LED, and I also added an EOTech XPS 2-0. With these items, the three rail covers, and a 30 round PMag loaded with 55gr ammunition, the weapon weighed in at almost 10 pounds 8 ounces. I should add that the XPS is less than 2 ounces heavier than an Aimpoint T-1 Micro in a LaRue mount, so if you want an optic and a light on your SR556, you're going to be staring at 10 pounds loaded even without a heavier stock.

While swapping out the stocks, I checked the receiver extension tube to see if it was straight. Like every other SR556 I've examined, it was not. This is easily avoided during assembly - the tube needs to be held straight while the castle nut is being tightened, or the tube will turn with the nut. This really will have no effect on the function of the weapon, but it provides some insight on assembly and QC practices.



Ruger SR-556s are test fired with a full 30 round magazine. This is a test regimen I wholeheartedly approve of, and wish more manufacturers would follow.

This is the wear on the receiver extension tube after test firing. It is similar to the wear my Ares converted AR exhibited after a similar round count. Like the Ares weapon, the receiver endplate has not been staked to prevent nut rotation; so far, unlike the Ares weapon, carrier impacts on the tube have not caused the nut to come loose, allowing the stock to rotate and the weapon to become nonfunctional. There is no excuse for any hard-use AR - but especially for a piston/op-rod AR - to not have this item staked.



Ruger is a recognized industry leader in investment casting, and it's my understanding that they make their own fire control group parts. This can be a mixed blessing, but the trigger pull is quite good for a stock trigger, with little to no grit. Unlike other manufacturers, Ruger does not put grease on the fire control group contact points.



Ruger utilizes a notched hammer and a non-shrouded firing pin carrier. Should the disconnector fail, these items will hang up on one another, causing the weapon to become completely nonfunctional. This is fine as a safety feature to make lawyers happy, but is not preferable for a weapon that one might stake their life on.



Moving to the front of the weapon, we see the Ruger muzzle device, similar to those used on Mini-14 variants. The barrel, as many know, is hammer forged 41V45, chrome lined, with a 1/9 twist rate. The profile can only be described as very heavy. The gas port is forward of the standard midlength location, and the massive gas block is pinned with two massive pins that were pressed in with a massive press. These pins are the reason why the weapon is not completely user-serviceable (although Adco Firearms tells me that they can remove the gas block without any problems, allowing them to reprofile or flute/dimple the barrel - normal disassembly rates apply). The gas regulator is easily adjustable with the mouth of a cartridge case or other such object, but seems very resistant to unintended rotation. It offers four positions, from "no gas" to "full gas".



The bolt carrier group has been completely hard chromed, with the exception of minor pins and the ejector. It weighs in at 11.1 ounces, the same as the lightest of AR-15 bolt carrier groups. For the sake of comparison, the POF P-415 bolt carrier group is 11.4 ounces, and a standard M16 carrier group is 11.5 ounces.



Though the extractor spring did not appear to be as large or have as much oomph as the Bravo Company extractor springs offered in their upgrade kits, it did have an o-ring installed.



Function

Side note - A friend of mine is a gunsmith for a major firearm retailer, and he tells me that he's had 5 Ruger SR556s returned for functional issues. When he tested them, only one of the five actually exhibited problems - failures to extract with Wolf. Given the appearance of the extractor spring, I'm not completely surprised. As for the other four, maybe the owners decided that they just didn't like the weapon. If so, that's a pretty crappy way to deal with it. Don't lie to a dealer in order to get a full refund on a used product that works fine.

––––––––––––––––––––––––––––––––-

Today I made it to the range with the SR-556. I had 6 other rifles to shoot, so the total round count was limited, but I started to get a better feel for how the weapon handled.

I was in luck - also at the range was Mike Pannone of CTT Solutions and Viking Tactics. An all-around good guy, Mike seems always willing to take a minute (or an hour) to help me with my shooting technique. Today, he ran me through a drill he was working on for the Border Patrol agents that he's paid to train - two shots to the chest and one to the head of a silhouette at 20 meters, two shots at an IPSC A zone steel plate at 50 meters, then two to the chest and one to the head of the silhouette again, and finally back to the steel plate for 2 more hits.

My times with the Ruger SR-556 and an EOTech were in the 10.5 second range, though I was consistently missing shots on the steel plate at 50 meters. Shooting his own AR, Mike was in the low 6 second range - he said an 8 second run was, for him, "slow". Note that the EOTech XPS2-0, my time with it having expired, has been replaced with my well-used 552 on a LaRue LT-110 riser.



Below, I run through the drill with a BCM lightweight midlength. The steel plate is the black dot to the left of the silhouette. With the BCM (equipped with a TA33 ACOG), my times were in the high 8s to high 9s - no misses. Although the magnified optic certainly helped, it took a little time to get used to the extra weight out at the front of the Ruger, and I kept "overshooting" as I switched from target to target, which led to frustration, wailing, and gnashing of teeth on my part.



I did not bother with accuracy testing after zeroing the optic, though the weapon seemed consistent enough for the task at hand. Later, I shot the drill once more with the Ruger. It was a "clean" run - no misses - and although the timer was not available, the pace was similar to my earlier ~10-11 second runs. I should add that Mike Pannone considers a 10.2 second "clean" time to be average for the shooters he was training.

Recoil is quite mild - as one might expect from a 10.5lb AR-15 with a rubber buttpad shooting .223 American Eagle. Still, recoil characteristics are not ideal, and the weapon exhibited a little more muzzle rise than I expected. As you can see in the first picture of this review, fired cases were ejected between 4 and 5 o'clock - more to the rear than I'm used to. I left the weapon on setting 2 for the day, and experienced no malfunctions. My only functional complaint - if I really wanted to get nit-picky - was that the selector was stiff when going from "fire" to "safe", but not "safe" to "fire".

After that last drill, I tried holding the rifle at the ready for as long as I could - after only a few minutes, my arm became quite sore. Unlike a lightweight standard AR, which I feel that I could hold at the ready or low ready for a very long time, the SR556 was just too much for my weak limbs to hold up all day.



My initial impression of this weapon is that it is a decent firearm - it functions, and it puts the bullets where you want them to go. If you are willing to train with this weapon and this weapon alone - or its SR-556C brother - you will probably do quite well with it (them), and be happy with the performance of the weapon(s). However, as an AR-15, for my intended use, it is not exactly satisfactory. Its handling characteristics are so different than a "standard" AR-15 that I would find it disconcerting to go back and forth between the two, or at least, I would personally have a fairly steep learning curve every time I switched. It is also unsuited for comfortable all-day carry, such as when hunting or backpacking.

I would like to thank Mike Pannone for taking a good chunk of time out of his busy day to help me out with my shooting yet again. If you get the chance to take a class taught by him, don't miss out.

A good and fair review with very good pics, would have been better posted about a year and a half ago though.

I prefer a non-staked castle nut.

Yes, what was I thinking????   i got two Rugers!


Fine weapons!  and yes they are my go to guns.

to each their own. out of the 7 AR platforms ive fired, i wouldnt trade my 556 Ruger for any of them. including the S.C.A.R and others of the like.  not heavy at all for me and i could carry this and shoot it for extended periods of time with no issues.

Man, I don't think you could do any better than getting some bonus training from Mike Pannone.

Great review.  Would be interesting to see if a lighter AR improves your time on that drill.

I'm not quite understanding the comment about being unable to utilize in a hunting situation because of weight. You can easily get the rifle under 9 lbs in a hunting configuration and a good sling would not hinder you in the slightest.

In a comfortable configuration with a decent scope, I'm looking at 10 pounds. I normally have a rucksack and two long guns - a bolt rifle and an AR - but if I was just carrying one rifle, the whole point would be to save weight, so I'd go with a lightweight bolt rifle or an AR. But a 10lb AR would defeat the purpose of just carrying one rifle.

Recoil comparison

Interesting video clips.

Are both clips at the same speed?  It's hard to tell from just a couple clips but it looks like the Ruger's bolt (and spent casing) is moving quite a bit faster than the parts in the BCM.  I have found that the cyclic rate on full-auto is substantially higher in the Ruger as compared to a standard Colt M4 firing the same ammo.  The Ruger will finish a mag probably a full second sooner than a comparable Colt.  I believe this is due to dwell time within the two different operating systems since the gas in the Ruger starts pushing the transfer rod as soon as it enters the gas block.  On the Colt, the gas has to travel all the way back down the gas tube to start the carrier's movement.  This is with an "H" buffer in both guns.

I wonder if this lack of delay increases the lift of the Ruger.  I'm guessing the force of the bullet's recoil is a separate event in the DI gun and you're less effected by it and the follow-up movement of the carrier.  With the Ruger, the bullet creates recoil and then the carrier adds to this since it starts moving a c-nt hair before the first small recoil impulse passes.  In essence, you've got two forces at once instead of one and then the other.

Just a SWAG, of course.  It could be nothing other than the increased mass of the operating parts.

Yeah, they're at the same speed. I have closeups of the Ruger action and will determine carrier velocity. I've already done so for suppressed and unsuppressed ARs with various buffers. The Ruger does seem to cycle faster. I tried to email you another video, but the email bounced.

I bet the muzzle rise is related to the muzzle device.

The video must be too big to make it through.  Can you post the video online somewhere and then send me a link?

Well done. An accurate assesment for the most part.

My biggest complaint about my SR also is the inability to easily disassemble some of the components as you pointed out. It's not that big of a deal but I sure wouldn't complain if Ruger got away from the pinned on component concept. I think they would experience an increase in sales if this change was made. I think a lot of people shy away from the SR for that very reason.  

Weight hasn't been an issue for me. I have so many ARs in different configurations that a change in feel and handling is normal when switching between weapons. Sometimes I use a 20" rifle. Sometimes a carbine or middy. I think limiting ones self to only one configuration might be a handicap in itself. However I can understand how someone carrying two rifles would prefer a lighter second rifle.  

I changed the stock and the selector on mine. Not totally happy with Rugers factory flash suppresor and may change that at some point. Overall the pros outweigh the few cons. The SR is a good rifle and a good value for those interested in a piston AR.

Anyway, nice objective review. Thanks for taking the time to do it.

 Seems very even handed, basically he said that it's a good rifle but wasn't for him. Judging by the number of customized AR's he shoots, an out of the box rifle probably doesn't suit him at all. I would like to see Ruger offer some proprietary polymer handguards that you can add rails to, instead of the quad rail, it would cut down on cost and weight.
 

Me too-I plan to get a SR-556, probably before then end of the year, but the pinned rail has given me pause. Options are never bad and a MOE-esque option would be a good one.

My SR-556 is my patrol rifle, I agonized over my choice for a long time, and finally decided on this over doing a retrofit kit. I've so far put about 600rds through it with no problems. I've placed a tangodown foregrip, surefire taclight, & aimpoint comp m4s, & magpul ACS stock on it. It's been a great rifle. Yes if's on the heavy side, but I still can tolerate well even while toting it for a few hours. I use a 1 point sling. The only issue I have concern with is cleaning the regulator area. This is a little tricker but I manage ok. I love how much easier the BCG and receiver areas are to clean now that all that hot, dirty gas isn't being routed back there. Not that there's anything wrong with the direct gas system, it's been a tried and true platform, but I can't help but love this piston design.

^ Well said, couldn't have said it much better

I never clean anything, unless I need to take pics of internal parts on a white background - I don't want my "photo studio" getting all greasy. The same goes for my hands sometimes, if I need to pull the BCG out, I might wipe it down with a paper towel.
But I can definitely understand why SR556 owners like their rifles. It's not for me, but it is a quality weapon. I do believe that I would prefer it to a conversion.
Here is my initial video review, I may do a followup soon. Most of it is fairly close to the text above, so if anyone out there is easily bored, you might not want to waste time watching.

 

Excellent review and pics. I notice it's $600-$900 cheaper than pistons in it's class with Troys and whatnot... Heck of a deal too.

-JD

Great review for the most part.

Totally agree with the weight issue and CG. The CG is my biggest issue.

I added a Magpul ACS and I have 4 AA batteries to help balance the weapon along with a 517 a bit farther back than where I would lime to have it. It's alot better.

87GN, you may wanna give the SR-556C a try if the forward weight is an issue.

87GN, thank you for the fair, well written review.



As an owner of an SR-556C, I agree that Ruger definately listened to their customers and addressed the weight issue. A friend of mine has the "non-C" version and there is a noticable difference in weight, but to be honest: it's no heavier than my Rock River CAR-A4 with heavy barrel. Maybe I'll break out a digital scale and see how they really compare!



Pinned barrel: I agree, not too thrilled about that, but my intent with the purchase (and I'm sure many other owners would agree) of the SR-556 is that it is "done". I don't need to monkey around with buying a $300+ rail system, BUIS, Hogue grip, and Magpull mags. It's all there. And hey, I get a piston system for a couple bucks too!



Again, thanks for a fair review. Ruger had problems with the first several hundred rifiles with extreme carrier tilt. They resolved that issue, but most reviewers seem to keep dragging it up. I appreciate you not muckraking like so many others have done!