Pat’s Product Review: Ruger SR556E

I’ve always been a big fan of Ruger firearms – all of them! There’s many reasons for my liking Ruger firearms, first of all, I find their firearms robust, strong and well-designed. Ruger doesn’t simply copy some other designs for the most part – instead, they are innovators in many ways. I still remember when the first Ruger P-85 9mm handguns came out, and everyone thought they wouldn’t last because they were made from “investment casting” aluminum frames- Ruger proved everyone wrong.
A few years ago, I tested the Ruger SR556 piston-driven AR-style rifle, and loved it. Everyone was jumping on the piston-driven AR bandwagon, and Ruger was no different, they than they didn’t copy anyone else’s piston-driven design – they came up with their own, after a lot of research and development. The SR556 comes with all the bells and whistles you can ask for, and then some – including a nice padded carrying case, several MagPul PMags – which I personally believe are the best AR mags on the market, and top-of-the-line pop-up front and rear sights and many other accessories, that don’t come on many AR-style rifles.
However, not everyone wanted or needed all that the SR556 came with as standard equipment, nor was everyone willing to pay the almost $2,000 price tag. Now comes the Ruger SR556E. Many people mistakenly believe that the “E” stands for an “Economy” model, but that is NOT the case. For the past several months, I have been testing the SR556E sample, and I have found nothing economical about this neat little rifle. What we have is a 5.56mm carbine, that can also fire .223 Remington ammo. The gun only weighs-in at a mere 7.36-pounds, a bit lighter and it balances better than the SR556 does in my humble opinion.  The SR556E also comes with a 16-inch cold hammer forged mil-spec 41V45 barrel with a flash suppressor on the end of the barrel. There is also a 6-position telescoping stock – closed the gun is 32.75-inches long and fully-open the gun is 36-inches in length. The flat top upper also has a forearm that has a Picatinny rail for mounting accessories at the 12:00 O’clock position and you can add other rails to the 3, 6 and 9 positions and these are sold separately. There is also a dust cover over the ejection port, and a forward assist – that I never recommend anyone use – it only leads to more problems, but it’s there just the same.The SR556E also comes with a soft padded carrying case.
I like the MagPul (I believe that’s the make) pop-up rapid deployment front and rear sights – they are outstanding. The front sight is adjustable for elevation and the rear sight is adjustable for windage. Where one would normally find the gas block for a direct impingement operating system, we have the patent-pending 4-position gas regulator. That’s right, this is NOT a direct gas impingement gun, it has a two-stage piston system that is chrome plated for easier maintenance, and the hot gases vent out of the bottom on this two-stage piston, causing the gun to run cleaner and cooler, and that is a very good thing in my book. The direct gas impingement system vents dirty, hot gases directly into the bolt and bolt carrier – causing guns to run dirty and very hot – not a good thing in many instances – it can lead to malfunctions if the gun isn’t properly cleaned and lubed on a regular basis – as in combat!
The 4-position gas regulator can also be completely closed off so the action doesn’t cycle for using a suppressor, where you don’t want any noise from the bolt cycling back and forth [or any sound of gasses escaping a gas port]. The other three positions are for running various types of ammo, and if your gun starts to run a bit dirty, you can adjust the gas regulator to a different position. Ruger ships the SR556E with the gas regulator set at the #2 position and suggests you do most of your shooting from this position. There is a complete tutorial video on the Ruger web site, that demonstrates the various settings. I left my sample on the #2 setting, and never looked back – although, I did play around with the different settings for just a bit – just to see how they function and how the gun ran – it ran fine in all but the closed position. However, for all my actual function testing and accuracy testing, the gun was left in the #2 position.
One thing you will readily notice with a piston-driven AR-style of rifle is the different recoil impulse. Hard to explain, but the gun runs a bit “differently” than a direct impingement operating system – it runs smoother, and it seems to run a tad quieter, too. Again, hard to explain, however if you shoot the SR556E next to a direct gas impingement rifle, you will hear and notice the difference in very short order. Now, some piston-driven AR-style rifles have had problems with “carrier tilt” – in that, the bolt carrier tends to tilt downward into the buffer tube, causing unnecessary wear and tear. Ruger overcame this problem by redesigning part of the bolt – removing some material here and there, and there isn’t any problem with carrier tilt. You might notice a little bit or wear from the anodized coating inside the buffer tube, but no actual wear on the material. Ruger did their homework – as they always do!
During my initial testing of the SR556E, I ran 5, thirty round magazines through the gun as fast as I could pull the trigger. When I was done, there were zero malfunctions, and I broke the action open and pulled the bolt carrier out – it was cool to the touch. Try that with a direct impingement AR and you’ll burn your fingers after just running one 30-rd mag through the gun. Additionally, the bolt carrier and bolt were still very clean – one mag through a direct impingement AR and the upper receiver and bolt carrier and bolt are dirty, very dirty – especially if you run some Russian-made .223 ammo through an AR.
I ran well over 500 rounds of various .223 Rem and 5.56mm ammo through the SR556E – however, in future testing, I won’t burn-up that much ammo – not with the big ammo drought we are facing, and my inside sources tell me that, they expect ammo to be in short supply for about two more years – or even longer, depending on the political climate in DC and in some states. Be advised and act accordingly. In future firearms tests, I’m only going to run about 200 rounds through gun samples. Even with my several sources of ammo for use in my articles, ammo is still hard to come by these days. My sources want to give me more, but they don’t have it – every round they make goes out the door each day – they don’t have a warehouse full of ammo any longer.
From Buffalo Bore Ammunition I had their Sniper .223 ammo – a 55 grain Ballistic Tip bullet, a 69 grain JHP and their heavy 77 grain JHP – which is recommended for barrel twist of 1:8 or 1:7 – the SR556E comes with a 1:9 barrel twist – the most popular for civilian AR style rifles. From the good folks at Black Hills Ammunition, I had a wide assortment of .223 – a 52 grain Match HP, 55 grain FMJ – new and reloaded, 55 grain SP, 68 grain Heavy Match HP and their newly released to the public, 5.56mm 77 grain OTM ammo – this is almost the exact same ammo that Black Hills Ammunition – and Black Hills Ammunition alone – provides to all the US Special Forces – no other maker produces this ammo. I also had a couple boxes of Winchester 55 grain FMJ USA brand .223 on-hand, and I use a lot of this for simple function testing – its a great round and less expensive than burning-up some more expensive ammo for function testing.
Once I had the SR566E zeroed, I did all my shooting at the 100-yard mark for accuracy testing – although the gun was zeroed for 300-yards – just my zero mark with all my AR-style of rifles. The Buffalo Bore, Black Hills and even the Winchester 55 grain FMJ loads were all giving me 3-inch groups if I did my part, with open sights, at 100-yards. This is about average for many AR-style rifles – nothing to write home about in the accuracy department. The Black Hills new and reloaded 55 grain FMJ ammo gave me the same accuracy results, so don’t go thinking you are getting slighted by using reloaded ammo instead of brand-new ammo all the time. The Black Hills 52 grain Match HP load gave me groups a little under 3-inches – better, but I knew the SR556E could do better – a lot better. I should note that the Black Hills 55 grain SP gave me 3-inch groups as well – and this would make a dandy load for varmints – even smaller dear, at close-in ranges. Although, I suggest using a larger caliber rifle round for deer – the .223 can still do the job if you place your shots where they need to go.
The Buffalo Bore 69 grain JHP was giving me groups right at the 2-inch mark, and I was starting to get impressed with the Ruger. The Black Hills Ammunition, 68 grain Heavy Match HP load was giving me groups around an inch and a half if I did my part – I’ve found this to be a very accurate load in all AR-style rifles I’ve tried it in. I ran out of the Buffalo Bore 69 grain JHP load, just as I was getting a good feel for it – and I believe it can match the Black Hills 68 grain Heavy Match HP load in the accuracy department.
Last up were the two heaviest loads, and you should be advised that, some rifles with a 1:9 barrel twist will only accurately shoot bullet weights up to about 68 or 69 grains – some will even shoot 75-grain bullets – but not all. Each gun’s barrel is a little different, and as I’ve said before in my articles, experiment with your gun and various types, brand and weights of bullets, to see which one will shoot most accurately in your gun. The Buffalo Bore 77 grain JHP and the Black Hills 77 grain OTM 5.56mm loads were both giving me groups in the 3 to 3 1/2 inch range. I honestly didn’t expect either one of those rounds to actually give me accuracy this good – considering the SR556 has the 1:9 inch barrel twist. I will admit though, that there were some groups that opened-up quite a bit more – however, I was advised by both Tim Sundles at Buffalo Bore and Jeff Hoffman at Black Hills, that it might be a waste of good ammo, shooting these heavier loads in the 1:9 barrel twist. Well, not a waste of money, but it proved to me, that in a pinch, you can shoot these heavier bullets in the 1:9 inch barrels, just don’t expect the accuracy you think you’ll get. I have fired both of these loads in another AR-style rifle with a 1:7 inch barrel twist, and had outstanding accuracy in the one inch to an inch and half range if I did my part. So, I know both of these heavier loads can shoot a lot more accurately in the right barrels, than they did in the SR556E.
During all my testing, I had no malfunctions of any sort. When I tested the original SR556 when it first came out, I did have a couple failures to extract in the first magazine, but after that, the gun ran fine. So, I was very pleased with the performance of the SR556E over the course of more than 3-months of testing. I never cleaned the gun during all this time, nor did I give it any further lubrication, other than the day I got the gun and inspected and lubed it. The gun was extremely clean at the end of my testing – and I believe I could have easily shot several thousand more rounds without any problems or further cleaning or lube. The SR556E with the two-stage piston-driven system really proved it’s worth and ran cleaner and cooler than direct impingement ARs do. There is no comparison between the two systems in my humble opinion. If you want a gun that runs smoother, cleaner and cooler, you need to take a close look at the SR556E, as opposed to a direct impingement operating system. Now, with that said, I’m not about to take my other ARs that are direct impingement and sell them or toss them in the trash – they all work just fine – I don’t keep guns around that don’t work – simple as that. I either make them run properly, or I get rid of them if I can’t fix the problems.
Now for the good news and the bad news. The good news is, the Ruger SR556E has a full-retail of only $1,375 and that’s a bargain in my book – for all that you get – there are other piston-driven ARs on the market that retail for a whole lot more, but they don’t give you more. Now for the bad news, with the big drought on all AR-style guns these days, if you can find an SR556E, they are going for about $2,000 these days. No, Ruger did not raise their prices, it’s just supply and demand, and all SR556 rifles are in great demand, ever since they came out, people have wanted them. If you’re in the market for a gas-piston AR, then take a very close look at the SR556E from Ruger – I think you’ll like what you see – just don’t pay too much – shop around and spend your money carefully. Now, after my wife shot my sample SR556E, she wants one of her own – she owns a different brand of AR-style rifle – a direct impingement version and while she shoots it very accurately, and hasn’t had any problems with it – other than a few hang-ups with some Russian-made .223 ammo – she just likes the way the SR556E handles, and she doesn’t hear that “twang” inside the buffer tube, like you hear with many direct impingement ARs – I personally don’t hear it – after so many years of shooting, I have some hearing loss. But now I have to find a way to not only pay for my own SR556E sample, I have to see if Ruger can ship me another one for the wife. I should have learned long ago, to not let my wife shoot any of my gun samples, she has fallen in love with more than one and ended up in her growing collection.  – SurvivalBlog Field Gear Editor Pat Cascio