Ruger® AR-556 Review
Part 3 - External & Operational Features
November 28, 2014

Ruger AR-556 Review

In this part of my Ruger AR-556 Review, I'm going to try to cover all of the external and operational features of Ruger's new AR platform rifle.


This first photos shows an isometric view of the AR-556.  Note that the bipod does not come with the rifle and is used to help me support the rifle while taking photos.  Although, this does bring up a good discussion point.  Since there is no rail system on the handguard or gas block, installing Picatinny rail accessories (like a bipod) are not directly possible without some type of adapter or mount. Since I consider this an entry level AR focused on providing low cost and value, this lack of rail is not a big deal.  You can always upgrade this system in the future because Ruger chose to use a conventional style barrel/handguard (barrel nut) attachment that is easily removed (more later in the review).

Figure 1
Ruger AR-556 Review: Isometric View

The exterior of the rifle has a fully black appearance from the type III hard coat anodizing on the aluminum parts, black oxide finish on the steel parts and black material of the synthetic parts.

Figure 2
Ruger AR-556 Review: Top View

As you can see, the rifle comes with a fixed A2 style front sight, flip-up rear sight and collapsible buttstock.  The rifle measured 32.38" with the buttstock in the fully collapsed position and 35.63" in the fully extended position.  The height was about 8" from the bottom of the pistol grip to the top of the A2 sight.  The width measured about 2.5" across the charging handle to the edge of the forward assist button.

Figure 3
Ruger AR-556 Review: Right Side

Figure 4
Ruger AR-556 Review: Bottom View

Figure 5
Ruger AR-556 Review: Left Side

The rifle, without a magazine, weighed in at 6.53 pounds which is close enough to the 6.50 advertised by Ruger.  This weight is similar to that of other rifles with comparable features and configurations (e.g. Smith & Wesson M&P15 Sport™).

Figure 6
Ruger AR-556 Review: Weight 6.53 pounds

Ruger chose to go with their Ruger styled flash suppressor which is threaded on the barrel with a standard 1/2"-28 thread.

Figure 7
Ruger AR-556 Review: Flash Suppressor

I believe the flash suppressor for this rifle may be a new version that has been shorted slightly and includes a set of wrench flats for removal if needed.  The suppressor is installed with a crush wash to allow for clocking the position of the vent slots.  Since this flash suppressor does not have a solid bottom similar to an A2 flash suppressor, you should expect to get some dust signature if you are close to the ground when firing in the prone position.

Figure 8
Ruger AR-556 Review: Flash Suppressor

Because of the carbine length gas system and 16.1" barrel, the barrel and flash suppressor extends about 8" forward of the gas block.  The black oxide finishes on the suppressor and barrel were a perfect match and have an overall nice finish. 

Figure 9
Ruger AR-556 Review: Flash Suppressor and Barrel

Figure 10
Ruger AR-556 Review: Flash Suppressor and Barrel

The barrel diameter forward of the gas block measured about 0.700" and rear of the gas block measured about 0.850".  Ruger calls this barrel a medium contour barrel.  The barrel is cold hammer-forged from 4140 chrome-moly steel.

Figure 11
Ruger AR-556 Review: Barrel

Figure 12
Ruger AR-556 Review: Barrel Under Handguard

The top of the barrel is stamped "5.56 NATO 1-8".  The 5.56 NATO is the caliber which will also allow you to shoot .223 Rem ammunition without issue and the "1-8" is the twist rate on the barrel.  For every 8 inches of barrel length you get one full revolution of twist.  This twist rate should stabilize bullet weights ranging from 35 to 77 grains according to Ruger.  In reality, I think the majority of the shooters purchasing this value rifle would stick with more value line ammunition which is typically found in either 55 or 62 grains.

Figure 13
Ruger AR-556 Review: Barrel Caliber & Twist

If you didn't already notice on the lower receiver, you may notice on the barrel that this rifle does not state "Newport, NH" which is Ruger's main manufacturing facility.  Instead the barrel states "--- RUGER · MAYODAN, NC · USA ---".  Ruger purchased this facility at the end of last year and I expect we will be seeing many more new firearms from Ruger produced out of their newly acquired 220K sq.-ft facility.  The barrel also has the typical "BEFORE USING FIREARM READ INSTRUCTION MANUAL".

Figure 14
Ruger AR-556 Review

Ruger incorporated a traditional styled A2 F-height front sight into the AR-556 rifle, but tweaked the slight configuration some to give the sight a unique appearance.  This F-height sight is slightly taller than the standard height and is designed to work best with flattop upper receivers.  Ruger states the "F-Height allows co-witness with many optics"  and I believe this to be true.  The sight comes with a standard elevation adjustable front sight post and Ruger also supplied a front sight adjustment tool which was a nice touch.

Figure 15           
Ruger AR-556 Review: A2 Front Sight             

The front sight is incorporated into a milled steel gas block that includes a bayonet lug and QD socket.  The front ramp of the sight is serrated to add a nice look and reduce glare and the rest of the sight is skeletonized to reduce weight.  The sight is pinned to the barrel with two tapered pins.  If for some reason you were not a fan of the A2 style sight on a flattop rifle, swapping the sight with a railed gas block should be fairly simple by removing the two pins.  The diameter of the barrel under the gas block is 0.750" so finding a replacement gas block would not be an issue.

Figure 16                                  Figure 17                                       Figure 18       
Ruger AR-556 Review: A2 Front Sight  Ruger AR-556 Review: A2 Front Sight  Ruger AR-556 Review: A2 Front Sight

Figure 19         
Ruger AR-556 Review: A2 Front Sight             

I performed a test fit of the QD socket with a Midwest Industries Quick Detach Sling Swivel and it worked like it should without issue.

Figure 20                                                            Figure 21
Ruger AR-556 Review: A2 Front Sight QD Attachment  Ruger AR-556 Review: A2 Front Sight QD Attachment

Next I installed a BLACKHAWK! Rapid Adjust Black Two-Point Sling in anticipation of future shooting adventures.

Figure 22
Ruger AR-556 Review: With Sling

Since the Ruger AR-556 comes with a bayonet lug, I had to mount my Ontario M9 Bayonet.  I found that mounting the bayonet was an extremely tight fit to the lug on the gas block.  This same bayonet fits easily on two of my other ARs, so I feel that dimensions on the Ruger lugs must be on the high side of the tolerance.  The carbine length gas system and 16.1" barrel places the standard bayonet more rearward than most might expect or want.  I believe a bayonet on a carbine rifle is really intended to be used with a 14.5" length barrel.  Also, the ring on a standard bayonet will ride on the barrel and not the flash suppressor.  Since the barrel is smaller in diameter than the flash suppressor, the fit around the barrel is very loose.

Figure 23
Ruger AR-556 Review: With Bayonet

In reality, I took these photos for your viewing pleasure and don't intend to put this bayonet on this rifle.  At some point I may look into bayonet lug mounted adapters and find a good use for this lug in the future.

Figure 24
Ruger AR-556 Review: With Bayonet

The Ruger AR-556 comes with a black polymer handguard.

Figure 25
Ruger AR-556 Review: Handguard

The portion of the handguard that you grip measures just over 6" in length.  The handguard includes the Ruger logo on the top and bottom.

Figure 26
Ruger AR-556 Review: Handguard

The handguard is made from two identical parts held in place by the steel ring behind the front sight and the polymer ring that is threaded onto the barrel nut.  You can remove the handguard by screwing the ring towards the receiver and then separating the two halves and rotating them out of the front ring.

Figure 27
Ruger AR-556 Review: Handguard Side

If you notice in the second hole from the Ruger logo in the photo below, you will see that a proof mark is stamped into the barrel.

Figure 28
Ruger AR-556 Review: Handguard Bottom

The portion of rail on the flattop upper receiver is not marked with slot positions and I personally don't see this as an issue.  I typically install my rear flip-up sight at the rear most position and then my scope mount in the next position possible.

Figure 29
Ruger AR-556 Review: Upper Receiver Top

The forged upper and lower receivers are made from 7075-T6 aluminum which has become the standard alloy for most quality ARs.  Each receiver comes with a black type III hard coat anodized surface which is also a standard finish.  I would call the upper receiver full featured because it includes a dust cover, case deflector and forward assist.  These features tend to be omitted on other rifles that compete in the same price range as the Ruger AR-556.  Another nice touch is that Ruger included their branded pistol grip which looks very similar to the Magpul MOE® Grip.  My guess is that Magpul may be making these for Ruger, but that is only speculation on my part.  This grip has an extended trigger reach by the increased width at the back of the grip.  This extended reach is intended to give you better trigger control.  The rifle also has a standard style magazine release and marking to show the position of the safety.

Figure 30
Ruger AR-556 Review: Upper and Lower Receiver Right

The bottom of the pistol grip is open like most AR grips.

Figure 31
Ruger AR-556 Review: Lower Receiver Bottom

Another feature that Ruger included is an enlarged polymer trigger guard for shooting with gloved hands.  The left side of receiver has your standard controls such as two position safety and bolt release. 

Figure 32
Ruger AR-556 Review: Upper and Lower Receiver Left

The lower receiver includes the standard marking such as model "AR-556", brand and logo "Ruger", manufacturing location "Mayodan, NC USA" and serial number.

Figure 33
Ruger AR-556 Review: Lower Receiver Markings

Both the upper receiver and aluminum charging handle include the Ruger logo.  Other than the logo, the charging handle looks very basic.

Figure 34
Ruger AR-556 Review: Charging Handle

These next two photos show the dust cover in the closed and open positions.  You can also see that the case deflector has some marks on it from when Ruger test fired the rifle.

Figure 35
Ruger AR-556 Review: Ejection Port Door Closed

Figure 36
Ruger AR-556 Review: Ejection Port Door Open

This next photo gives you a limited look at the side of the black oxide finished bolt carrier.

Figure 37
Ruger AR-556 Review: Bolt Carrier Forward

Ruger put a standard single stage trigger in their AR-556 which is the norm for an entry level AR.  The trigger pull measured 7.6 pounds based on an average of 10 pulls using a Lyman Digital Trigger Pull Gauge.  This pull weight is in the middle of the range of 5.5 to 9.5 pounds for a standard M4 rifle.  The photo below also gives you a closer look at the enlarged polymer trigger guard.

Figure 38
Ruger AR-556 Review: Trigger

The magazine well looks pretty standard with a slight chamfer around the inside edge and the rifle comes with a single 30-round Magpul® PMAG® magazine.

Figure 39
Ruger AR-556 Review: Magazine Well

Ruger did a good job on cleaning up the forging.  You can usually tell how well a manufacturer cleans up the lower receiver forging by how well they remove the mold marks on the front of the magazine well.  The upper and lower receivers on this rifle were probably the best fit I have ever evaluated.  There was zero freeplay as if they were a matched set, yet I was still able to remove (barely) the takedown pins without any tools.

Figure 40
Ruger AR-556 Review

For the rear sight, Ruger added a rapid deploy polymer sight that is adjustable for windage only.

Figure 41
Ruger AR-556 Review: Rear Sight

The Owner's Manual states that each click of the wheel will adjust the point of impact 0.625" at 100 yards.  The sight is spring loaded to pop up when the button on the left side at the base is pressed.  When in the up position, the sight is not locked in place, so if hit by accident, the sight would fold back down and not be damaged.

Figure 42
Ruger AR-556 Review: Rear Sight

This next set of photos gives you a good look a the sight.  Notice that this sight has a single peep hole (single diameter).  If for some reason you would want a larger hole (aperture), you would need to drill out the hole to a larger size.

Figure 43                      Figure 44                         Figure 45                       Figure 46        
Ruger AR-556 Review: Ruger Flip-Up Rear Sight  Ruger AR-556 Review: Ruger Flip-Up Rear Sight  Ruger AR-556 Review: Ruger Flip-Up Rear Sight  Ruger AR-556 Review: Ruger Flip-Up Rear Sight

Notice that the attachment screw must be removed to slide the rear sight on the rail (typical of most).  The screw then applies the clamping force to hold the sight in place and also prevents the sight from shifting position on the rail. I thought this might be a good time to also show the front sight which is adjustable in elevation.  The elevation point of impact will change 1.75" at 100 yards for every 1/4 turns of the front post.

Figure 47                                   Figure 48     
Ruger AR-556 Review: Ruger Flip-Up Rear Sight  Ruger AR-556 Review: Front Sight

Ruger included their standard 6-position adjustable buttstock on the AR-556.  This adjustable buttstock allows the length of pull to vary from about 10.25" fully collapsed to 13.5" fully extended.

Figure 49
Ruger AR-556 Review: Buttstock

The buttstock includes a textured surface on the butt to help prevent from sliding off your shoulder and also include two locations for attaching a sling. 

Figure 50
Ruger AR-556 Review: Buttstock



As I have been going through the details of this part of the review, I kept thinking "what a great value."  The materials and features of this rifle with a name like Ruger to stand behind the product for a potential price of $600 to $650 is truly a great deal.  The only feature I found a little squirrely was the bayonet lug on a carbine gas system with a 16.1" barrel.  The bayonet seemed mounted too far to the rear and perhaps an adapter of some type could make the lug more useful. Other than that, nice job Ruger!

For more detailed photos and commentary, make sure you check out the other parts of this review and feel free to leave comments on my Reader's Comments page.  The following links are provided to help you see other parts of this review. 

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