Armalite AR-10 PRC in .260

 Armalite AR-10 PRC in .260—Full Review.

The PRC 260 from Armalite delivers a high-end precision rifle in .260 Rem. ready for effective suppressor use.

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To learn more, visit https://armalite.com/shop/ar-10prc-260308/.

My introduction to the .260 Remington occurred about five years ago during a hog hunt with my friend from Mike’s Guns in Texas. Meeting up at his shop prior to the hunt, he let me spend some time with an AR-10 he built in .260 Remington. Using his rifles in .308 provided a solid comparison, and the .260 Remington was impressive. Especially when suppressed, it was softer shooting then some of my 5.56mm ARs.  Trimming the gas a bit made it reliable, quiet, clean, and incredibly accurate.  Testing a bolt rifle of his in the same round a bit later, the accuracy potential of the round became clear. Using some of his handloads, I produced several groups in the 0.20 inch range. But therein lay the problem; the need to reload. Factory match ammunition was all but non-existent at the time. Black Hills Ammunition loaded some in their premium line, but that was about it. Since reloading was not in the cards for me at the time, it was not something I pursued.

The rifle proved to be as capable with a suppressor as it did without, being reliable and accurate.

It was the introduction of the 6.5 Creedmoor and its surge in popularity amongst the precision competition crowd that brought the 6.5mm back onto my radar. Factory ammunition becoming available the 6.5mm all but eliminated the .308 rifle from my precision rifle inventory. It shoots flatter, softer, more precisely, and reaches out to much longer range. With a wide selection of factory match ammunition available for the Creedmoor it was becoming a favorite of many precision shooters unwilling or unable to reload. While the .260 Remington remained popular amongst reloaders and hunters, factory match ammunition remained scarce.  However, the .260 Remington was making huge inroads in the military, at least at the operational level.  Talking to Special Missions Unit members, they swear by the .260 Remington and have been requesting rifles for years. While it likely will not make a big splash on the main stage, at the smaller unit level they are starting to creep in. All of this combined has finally sparked a surge in precision rifles and factory match ammunition for the .260 Remington. Cost is still higher for .260 Match, but there are several commercial loads now available.

The author topped the 20-inch barrel off with an AWC Thor PSR suppressor.

ARs Chambered in .260 Remington

As evidenced by my early experience with an AR-10 in .260 Remington, it can be done. Most early rifles were custom built with a few factory rifles popping up on occasion. A few seemed to think it was harder to build an AR-10 in this caliber, but others never seemed to have the same issues, including Mike Brown of Mike’s Guns, or me.  Having assembled a few over the last couple years they were easier to tune than similar .308 models in my experience. In an industry chock full of mythology, it was dismissed in my case. More often than not they are excuses to “not” do something. It was only a matter of time before demand outstripped any problems (real or otherwise)  limiting rifle availability. Much of the demand was for an AR-10 that would work suppressed though, and that is problematic unless tuned solely for suppressed use. What we really needed was a rifle with a “shortish” barrel that allowed for use suppressed and unsuppressed without requiring re-tuning. It has been tried in the past with moderate success but it looks like Armalite has now taken that idea to a whole new level with the AR-10 PRC in .260 Rem.

The adjustable gas block sits underneath the hand guard. Note the short rail sections for accessories.

SPECS

• Chambering: .260 Rem.
• Barrel: 20 inches
• OA Length: 41.3 inches
• Weight: 11.4 pounds
• Stock: Magpul PRS
• Sights: None
• Action: DGIS
• Finish: Dark brown Cerakote
• Capacity: Variable
• MSRP: $3,560

Armalite AR-10 PRC 260

Armalite designed this rifle from the ground up to be a precision semi-automatic rifle. It’s not just a standard rifle with a precision barrel and chamber. Along with a match quality 20-inch stainless steel barrel, it includes a new gas block allowing for reliable transition between suppressed and unsuppressed fire. Working together with Surgeon Rifles and AWC Silencers, the AR-10 PRC 260 is a well-integrated purpose-built rifle designed with some serious thought.
The rifle I received for testing was a very early production model and the company asked me to give them feedback on it. It starts with Armalite upper and lower receivers forged from 7075-T6 aluminum. The upper includes a forward assist, dust cover, and brass deflector. It houses a coated bolt carrier group using an AXTS  Raptor Ambidextrous Charging handle. The barrel is 20 inches, heavy contour, stainless steel, and includes a Surgeon/AWC PSR thread-on muzzle break designed for the .260 Remington. It operates as a standalone break or an AWC Silencers THOR PSR can be added.  Using a 1:7 twist rate better stabilizes bullets at distance given the relatively short barrel length. A proprietary gas block with a two position lever runs the rifle-length gas system. It is optimized for use with the PSR suppressor and can be accessed through the 15-inch hand guard without tools.  Short rails sit at the front and back of the hand guard with a continuous top rail. Slimmer in the middle, it shaves weight and provides for comfortable hand holds. Threaded holes sit at the front of each short forward rail for sling stud use.

The rifle features a Cerakote dark brown finish that keeps it very low profile. Note the ambidextrous safety.

Armalite uses a “B” series lower receiver that accepts SR25-patterned magazines. It has a Magpul PRS stock attached using a rifle length buffer and spring. It houses a Timney single stage trigger using an AXTS Talon ambidextrous safety. The pistol grip is a Magpul MIAD. Sling loops sit on the right side of the PRS stock but can be moved to the other side if needed. Production rifles will be shipped with one 10-round PMAG.

Testing

Burris Optics provided a new  XTR II 5-25x 50mm FFP (First Focal Plane) scope for testing.  Utilizing their SCR Mil Lined reticle provides ample lines for holding elevation or wind. It was mounted in a Larue Tactical PSR20 mount. Clarity on the glass is excellent and the reticle is comparable to any simple Mil lined reticle on the market. The vertical line has 20 mils graduated in half mil increments below the horizontal line. There are 5 mils above with the last two graduated in .10 mils. Extending on either side are 10 mils graduated in .2 of a mile for the first five where another .10 mils section sits for ranging calculation. The center section is lighted for 3 mils on either side and 6 mils below the center line. Dialed up to 15 power there were 11 mils available for holds with the entire horizontal line visible. Knobs are tactile with audible clicks at .10 mils per click and 10 mils per revolution. Numbers are easy to read. The XTR uses a zero stop that is easily adjusted. Loosen the screws, slip the knobs to zero and press firmly and re-tighten. Parallax adjustment sits on the right along with lighted reticle activation. There are 11 settings with “battery saver” steps in between each setting and a hard “off” setting at both ends. Scope covers that flip flat against the scope when open are included.

Burris Optics provided a new XTR II 5-25x 50mm FFP (First Focal Plane) for testing.

Since this rifle was designed to be used both suppressed and unsuppressed, my AWC Thor PSR suppressor was used. Designed to meet the original PSR contract it is a Titanium suppressor designed for multiple calibers up to and including .338 Lapua Magnum. Threading over the muzzle brake it means no shift in impact when removed and reinstalled.  It’s also very quiet and as rugged as it gets.

Tuning Your AR

With my having tested hundreds of ARs over the years, I have found that the vast majority are over-gassed. It’s required to allow base line customers the ability to use whatever ammunition they can find (often of very poor quality) and still have it run.  The problem being is that when precision match ammunition is used, often loaded to higher velocities, these guns are harsh to shoot. It can also affect accuracy and reliability. For a weapon designed for “battlefield pickup” drills using whatever trash ammunition found on the ground that is fine.  But precision ARs, especially those using DI (direct impingement) gas systems, benefit hugely from tuning. Having tuned dozens in various calibers, it makes a huge difference. It encompasses matching the gas delivered to the bolt carrier group with the mass of that group, coupled with proper spring tension and buffer use. It results in a softer shooting, cooler running, and more accurate AR. It means you cannot throw whatever reloaded ammunition you find on the ground in it though and expect it to work. You will need to stick to quality ammunition with similar pressure curves.

The rifle came with an AXTS Raptor ambidextrous charging handle.

Adding a suppressor generally adds to the complexity. Over gassed ARs dump excess gas into the action and magazine along with your eyes and lungs. Many will just quit working after a couple of magazines they are so covered in gunk. Tuning for suppressed use helps a ton, but most won’t run if you remove the suppressor. There are some adjustable gas blocks out there that facilitate that, but most clog up, shake loose, or flat-out break under hard use. The simple solution for some rifles is a two-position block that is robust and tuned to the rifle’s use. Few pick up a $3,500.00 AR in .260 Remington for battlefield pickup drills, making it easier to tune it for match grade ammunition. Given a collaboration between Armalite, Surgeon, and AWC, they were able to make this work very well.

 Range Testing

I expected this rifle to be accurate, what most interested me was how the gas block worked using various bullet weights suppressed and unsuppressed. I have often abandoned testing .308-based ARs with a suppressor since they just don’t always work, no matter the suppressor. A bit to my surprise, this rifle worked well, very well in fact!  Starting with some Nexus 136 Grain Lapua, it was fired without the suppressor. Loud, as expected, recoil pretty well mitigated, significant dust signature and brass was ejected smoothly at four o’clock.  Moving the lever over and attaching the PSR, the exercise was repeated with the same results. Excess gas was minimal, brass ejection was in the same place, only this time no muzzle blast. First round push was minimal and it was softer to shoot than a couple of recent 5.56mm rifles tested. The same process was repeated using Federal Gold Medal Match 143 grain SMK, Gorilla 123 Grain SMK and Nosler 120 Grain Ballistic tip yielding the same results. Using controlled fire, the brass ejection was consistent with no failures to eject or return to battery. Rapid fire strings (five rounds rapid fire) using the suppressor saw ejection walking forward to about two o’clock but remaining reliable.

The Nexus load did extremely well, turning in groups as tight as .60 of an inch.

The Nosler load also did quite well, with a tightest group of .64 inches.

Accuracy was as good as it gets with an AR-10, at least for me. My best groups came from the Nexus 136 Grain Lapua at .60 inches. Nosler’s 120 Grain Ballistic Tip was only slightly larger. Every rifle tested so far has grouped the Nosler either the tightest or a very close second. Groups were all under an inch, most between .60 and .75 inches. Since grouping at 100 yards does not always mean it will hold at range, the PRC was tested out to 1,000 yards on steel. Using data from the Kestrel, five rounds of the Nexus 136 Grain Lapua were loaded up and fired at 1,000 yards just after dawn, so no wind, perfect conditions. Target is 12-inches wide by 16-inches tall. All five hit home with a group about the size of my hand ( a tad under 8 inches) measured through the scope. Groups shrunk to fist-sized at 500 yards. All of this was completed using the suppressor, mostly because it was such a pleasure to shoot suppressed. Timney’s trigger was crisp and there were no light primer strikes. My guess is the 1:7 twist is a strong contributor to accuracy at range. There are some strong advocates for faster twist barrels on long range cartridges when they are shortened, and it seems to work here.

The stock that came on the test rifle was a Magpul PRS unit.

Other Considerations

The contour on this barrel is about as big as you can get and still get it to fit under a hand guard. Accuracy is the result, along with minimal recoil, but its no lightweight. Listed weight is 11.4 pounds, unloaded, with no scope. The barrel tapers so most of the weight is back towards the receiver, but it’s about the same weight as most precision bolt rifles. Remove the suppressor and it’s pretty handy. Most of my personal builds in 6.5mm use a 20-inch barrel and it’s the best compromise. Adding the suppressor does not make it unwieldy, but it does add about 7 inches after attachment of the PSR brake. Attaching the suppressor shifted the point of impact 3 inches low. Removing it returned to zero every time.

The PRC 260 rifle really held its own under testing by the author. It is expensive, but it really delivers.

Final Thoughts

Armalite built this rifle to be strong, accurate, reliable, and repeatable. They did an excellent job; not sure it has been done any better outside a straight-up custom build. There were no failures to function using PMAGS, DPMS and my Larue Tactical magazines. It’s billed as a precision rifle that “offers consistency in suppressed and unsuppressed configurations,” and that it does. I have tested custom rifles with similar consistency, but nowhere near as simple, nor likely as robust.
To learn more, visit https://armalite.com/shop/ar-10prc-260308/.