Quickly and easily convert your Ruger SR556 Takedown rifle to .300 AAC Blackout with this barrel kit. Oh, and best of all, easily running both supersonic and subsonic in the same rifle with absolutely no change in the gun. In fact, it is this latter capability that 300 BLK owners find most attractive.
So the .300 Blackout can drop a deer at 200 yards, or lob 30-cal lead downrange with little more noise than a cycling bolt. The SR-556 Takedown maintains the best-of-class elements of the SR-556 and comes standard with a host of accessories that today's shooters demand. The quad rail handguard provides ample mounting area for accessories and provides a stiff and secure mount for the takedown mechanism. The slider bar for removing the barrel is located on the bottom rail under the gas block and is out of the way of accessories.
The upper receiver is complete with dust cover, forward assist, and metal flip-up windage adjustable rear sight. A 10-inch barrel on an AR pistol or a short barreled rifle is perfect for the .300 Blackout. The uppers all feature different length handguards, that accommodate the mounted flash suppressor. The barrels are all equipped with a standard A2 muzzle brake that's been proven efficient and effective.
It's a Smith and Wesson product, what could really go wrong? This is as traditional an upper receiver as you'll get in the modern world. This is for a full-sized carbine and comes outfitted with a 16-inch barrel with a 1-7.5 inch twist, and a threaded muzzle.
Included is the Yankee Hill Phantom flash suppressor, which is a great touch. The upper assembly is a single unit, and while the author tested a quad-rail model, a KeyMod handguard is now available. The barrel assembly includes the front sight to ensure accuracy after being disassembled. The SR-556 Takedown has a standard lower receiver with a Magpul MOE SL buttstock. As I mentioned earlier in this article, Ruger designed the front sight to allow for windage and elevation adjustments so that the zero would be maintained when swapping barrels. I sighted the rifle in with the 5.56mm NATO barrel then swapped out to the 300 BLK barrel.
After sighting in the 300 BLK, I then returned to the 5.56mm NATO and shot a new group. As Ruger promised, the rounds were hitting where I intended. Swapping out once again to the 300 Blackout barrel assembly, I found those rounds struck paper right where they were supposed to. I don't claim that this is a comprehensive test, but it is certainly enough to suggest the gun does indeed hold its zero when taken down and then reassembled.
In addition to the rifle, Ruger shipped me a 300 Blackout conversion kit. The kit includes both a barrel assembly and two magazines marked as being for the larger caliber. When developed, the 300 Blackout was designed to work with standard 5.56mm NATO magazines. But having clearly marked, dedicated magazines can help a shooter avoid problems with trying to shoot the wrong ammuntion in the SR-556 Takedown. Thankfully, the carrying case has room enough to carry the gun and both barrel assemblies in addition to the magazines in the front pockets. I've found two options that I really like that come without barrels.
These are high-end uppers that are designed for builders who really want to tweak their builds. The end user will have to provide a barrel and gas system to the upper receiver to complete it. In order for the rounds to perform on the level of the AR15, 300 Blackout upgrades for the M4 carbine are necessary to ensure friction doesn't cause damage to the upper assembly or barrel over time.
There is no rule that says you cannot run both subsonic and supersonic ammo in the same mag. So imagine whitetail deer hunting in thick brush with the first round or two being subsonic and the rest being supersonic. With the gas tube removed, you can unwind the barrel nut freeing the barrel from the upper receiver. You can reuse the gas tube if its in good shape and the right length, and maybe even reuse the gas block as well assuming it works with your barrel and handguard. After more dead ends, I spoke to a Ruger N.C. CSR Replacement Specialist who asked me to send her a copy of a letter I'd written and gave me a direct way to communicate with her, and she'd take it to management.
A couple of weeks later, she sent an email saying a package is being shipped the next day. Inside was a SR556 TD 5.56 bbl assembly complete with front sight and gas block assemblies! I feel this was a "one off/unique" situation, but I'll take it. Positive feedback being sent to Ruger's N.C. HR Department. News people Radial pistol uppers are good to go for what they are designed to do. The only down side would be the barrels are 4140 so I would guess they won't hold up to high round counts.
But at their price point I can buy a complete upper for the cost of a barrel from other name brands. This receiver and handguard are designed to be a takedown model. This allows you to detach the handguard and barrel from the upper in seconds. This system is available with both a 13-inch handguard and a 7-inch handguard so you can go rifle or SBR/pistol route. The 16-inch option even comes complete with gas block and gas tube.
Brownells isn't going to stick their name on crap either. These barrels are made of 4150V steel and feature a Nitride finish for strength and durability. There is little similarity between the subsonic and supersonic trajectories so you will either need to memorize ballistics tables as well as know which round your sights are zeroed for. Luckily the limited range of the 300 BLK is something that iron sights can handle no matter the bullet weight.
Sure, a 6x optic will give you an accuracy advantage, but any good shooter can squeeze off plenty of precision whether iron or glass. Instead of swapping barrels, many of the Blackout-curious types will just build an entire upper dedicated to the 300 BLK and switch out the whole upstairs, sights and all. In my case, I was not excited about the DPMS AR 15 as a .223 in the first place, and didn't mind making a dedicated Blackout gun.
Plus, if your luck holds, you will have nothing more the cost of a barrel which is considerably less than an entire upper. And there is that in-between option where bolt and charging handle jump back and forth between calibers. As the .223 barrel had an A2 front sight, I chose to abandon it and install a Yankee Hill mini gas block inside the free floating handguard. Since I'll be running an optic on the top rail, I opted for some Magpul MBUS Pro Offset sights for backup and for longer distance shots.
By the way, if you are wondering the difference between a handguard and a forend, the particular part name has to do with whether or not the specific piece of furniture is just for support or to protect your hand from burns. It should go without saying that a 30 caliber subsonic suppressed round with a 200 meter range should have endless uses. But let's put a finer point on that protection thing.
A bolt cycling is noisy but only within a very limited sound radius. Add snow or thick brush or trees and the noise of a buffer spring boinging and bolt clanking will not travel far. And the thump of bullet impact is evidence that it's too late to do anything about it.
Unfortunately, the 30 caliber bullet leaving the muzzle under the speed of sound drops like a mountain pass after a hundred yards, and like a double-black diamond ski slope at 200 yards. Beyond that it's ballistics curve would be a boat anchor. The SR-556 Takedown's accuracy with 5.56mm ammunition was very good. Using the iron sights, sub-2-inch groups at 100 yards were fairly common. I tested loads with bullets weighing 53 to 62 grains, and all were solid performers. One of my favorite defensive choices, the 55-grain Hornady TAP Urban load gave the best five-shot group, which measured 1.38 inches.
I have found this load to be accurate in a wide range of rifles that I have tested, and it performs well in the ballistic gel tests that I have seen. All of the 5.56mm loads were completely reliable in the Ruger SR-556 Takedown. Completing the package, Ruger includes three rail covers for the handguard and a soft carrying case. The case is a lot shorter than a standard rifle case, as it is intended to carry the gun when it is broken down. The case has two large, zippered pockets on the front that allow for the storage of magazines, ammunition or other gear.
In practice, it would be easy to store this case behind a truck seat or in a trunk. The M&P Whisper comes with a flat top upper for all your optic's needs. The Whisper is designed solely for the .300 Blackout and utilizes a gas system designed to function with both subsonic and supersonic rounds. If you put a 300 blk barrel on an ar15 everything is ar except the barrel.
The ability to interchangeably run both supersonic and subsonic round through the same gun with the same bolt is truly revolutionary. So to be able to run either/or subsonic/supersonic rounds at whim means that you need keep your .300 ducks in a row, as well as your sights. My Blackout bbl kit (I've had it close to a year now) has proven to be nicely accurate .
Mine is shot 100% with a suppressor and likes the Barnes 110gr black tip bullets . I built a .300 in a A2 dissipator configuration, using a pistol length gas system. Very smooth and the accuracy is excellent with just irons. This list definitely should be updated to include gas piston systems. Primary Weapons Systems sells a complete upper exclusive on Brownells that is competitively priced compared to the others on this list, but you get a far superior action. I have recently joined an Anderson lower with a upper receiver that I got from Bear Creek armory for something around $200.
It carries a silencer central can and my property is super densely forested very few clear long shots so this is absolutely perfect for me. Just make sure and meet ATF's guidelines for AR-15 pistols. Lastly, this is a complete upper receiver, so it does include a charging handle and bolt carrier group. The S&W M&P Whisper is a simple system that's easy to suppress and rearing to go out of the box. Other shooters have used different colored magazines to differentiate between calibers, like loading standard black magazines with .223 and reserving flat dark earth mags for their .300BLK ammo.
More subtly, some shooters adorn their magazines with colored tape to make the designation clear. On this particular build, I zeroed the Aimpoint H-2 for the subsonic bullets at 50 yards, and zeroed the Magpul MBUS Pro Offset sights with the point of impact for supersonic bullets at 150 yards. Of note is that the stock front post has been replaced with Magpul's MBUS Pro Enhanced Front Sight Post, a tiny screw-in after-market post that improves accuracy by reducing post thickness.
In my case, I will run two 10 round orange-colored Magpul Pmag magazines while hunting. One is filled with my subsonic loads and the other with supersonic ones. But there is another factor that needs to be kept in mind and that is that 300 BLK ammo is widely available over the gun counter in both supersonic and subsonic varieties. And in some cases such as hunting, the shooter may want to switch between supersonic and subsonic on the fly. Given that the 300 BLK is still young enough to have spots it's not surprising that reloading your own brand is the go-to option for the more-than-curious. But the big news here is that there is actually a selection of subsonic 300 BLK ammo on the shelves of the big boxes.
So something's going in the right direction these days. Factory loads of 300 BLK come in several popular bullet weights. In general, those bullets over 200 grains slide down the pipe under the 1100 feet per second speed of sound while anything lighter breaks the sound barrier with a boom. Since most of the powder is burned within the first nine inches of barrel, near total performance can be achieved in very short barrels. To avoid paperwork and a tax stamp and months of delay, I opted for a 16" barrel literally off the shelf at a local gun store.
Changing a .223 AR 15 into a .300 Blackout can be as simple as swapping barrels. The complete upper, lower, magazines and gas system might work just fine with the 300 BLK. Usually there are a couple other parts that get changed out as well, but truly in a nutshell, it is just a barrel switch. So a best-case conversion to turn your .223 AR into a .300 Blackout is 1) remove your .223 barrel, and 2) install a 300 BLK barrel.
300 BLK ammo in the supersonic variety did pass my Walmart test. That means it is sitting on the shelf at the local Walmart right now. However, I was unable to locate any subsonic .300 Blackout ammo at the any nearby Walmarts. Of course, subsonic 300 BLK ammo was available at almost every gun store and big box sporting goods store I checked so the stuff is common. And the Walmart gun clerk did say they've had 300 BLK subsonic ammo in stock before, but it was elusive as 500 round bricks of .22 long rifle.
As I've come to expect in all of Ruger's rifles, the SR-556 Takedown is a quality weapon that earns its asking price. The gun is a high-quality build, and it does everything it claims with 100-percent reliable functioning. The features are well thought out, and the takedown system works very well.
The SR-556 Takedown uses a two-stage gas piston with a regulator that the shooter can use to tune the rifle to different ammunition and conditions. The system is designed to keep the gun cooler and cleaner, which should increase reliability with high-volume shooting. Modeled after the original SR-556 in 5.56mm NATO, the new gun adds the ability to twist and remove the barrel in just a few seconds. When matched with a 300 Blackout kit, the owner can literally change the gun from 5.56mm to 300 BLK in about 30 seconds. To take the barrel off, simply lock the bolt to the rear, pull down on two tabs along the rails under the front sight assembly and twist the barrel about an eighth of a turn.
Like the popular Ruger 10/22 Takedown®, the SR-556 Takedown was designed with ease of use in mind. The barrel is removed from the upper receiver by simply moving the slider bar towards the breech, rotating the barrel and pulling it free - no tools required. Installation is simpler yet - just slide the barrel into the upper and twist until it locks. I just talked to a ShopRuger customer service supervisor about my backordered 300 BLK barrel kit for the SR556 Takedown. She did say that they were "in process" of producing enough kits to fill current backorders.
