AR10 Tested: Cold War Legend Meets Modern .308

Estimated reading time: 15 minutes

The AR10 helped blow up old-school battle rifle thinking, gave birth to the AR15, and still hits hard decades later. We go from Eugene Stoner’s original concept to a Brownells BRN-10A and a modern PSA AR10 build to see what changed and what absolutely did not.

Four Cold War Battle Rifles Belong on Your Bucket List

Get a piece of paper or, better yet, text yourself this list: AR10, M14, FN FAL, and H&K G3. These four rifles were introduced after WWII by NATO nations as the Cold War metastasized. All were chambered in 7.62x51mm NATO. The caliber the U.S. military insisted all NATO members use. If World War III started, at least NATO members could share rifle ammo. The U.S. actually changed its mind and switched to 5.56, but that’s another story. Why add these rifles to your bucket list? These four rifles helped define the Cold War era and helped spawn later generations of combat rifles. Today we’re focusing on the AR10.

Why the AR10 Blew Up Battle Rifle Thinking in 1956

The sales and marketing guys from Armalite produced a promotional film; videotape wasn’t invented then, to showcase the new AR10. The film opened with a soldier emerging from the ocean, storming the beach, and firing an AR10 full auto. The film is impressive, creating a grand entrance for Armalite’s new design for combat rifles. The film goes on to showcase the innovative characteristics of the rifle and how it performed under extreme conditions like sub-zero temperatures and caked with mud. Eugene Stoner looks like an engineer from that era. All he needs is a pocket protector for his pens to go with his bowtie.

As the AR10 literally blasted its way into recognition, it blasted all the old-school thinking that a battle rifle needed to be made of blued steel and a wood stock. We take the AR10 and AR15 for granted these days. Spoiler alert: the AR10 was scaled down into the AR15, and that, too, is another story.

The AR10 offered an innovative new gas-operated bolt and carrier system, forged alloy parts, and a stock and forend made of polymer. The result was a rifle easier to control in full auto and over a pound lighter than any infantry rifle of that time. Sounds exciting, and it was, but the U.S. military wasn’t interested. They had changed their collective minds and wanted a rifle chambered in .223 Remington, which was officially accepted in 1963 and named Cartridge, 5.56 mm ball, M193. Again, another story.

🛒 Check Current Price for AR10 on GunsAmerica

Eugene Stoner, Hollywood Prototypes, and an AR10 That Blew Apart

In the late 1950s, Armalite was a division of Fairchild Aircraft Corporation with a focus on designing small arms concepts. It was a think tank for small arms design, and the business model was to design guns and sell or license the design to firearm manufacturers. The small shop was located in Hollywood, California, and employed a small group of talented engineers captained by Eugene Stoner.

Prototypes of the AR10 were developed in late 1955 and early 1956 when the U.S. Army was looking to replace the M1 Garand. Springfield Armory had a prototype M14, and Fabrique Nationale submitted a version of the FN FAL. See why I asked you to create a list? Armalite wanted to get in on the trials the Army was holding, and hand-built four AR10s for the trials. The Army test team liked the idea of the AR10, but a prototype’s barrel made of an aluminum and steel composite spectacularly burst during testing. The Army took a hard pass on the AR10. Unfazed, Armalite built more rifles for their sales team, and these AR10s became known as the Hollywood model because they were built in Hollywood, California.

Armalite expected sales of the AR10 to start rolling in and hired a Dutch arms manufacturer, Artillerie Inrichtingen, to produce large quantities of the rifle. Nicaragua was the first country to place an order, but after extensive endurance testing on a prototype, a Nicaraguan General almost ate part of the upper receiver when it busted apart. Naturally, the order was canceled.

There were other buyers of the AR10: Guatemala, Burma, Italy, Cuba, Sudan, and Portugal all purchased small quantities of AR10 rifles. In the end, less than 10,000 AR10s were produced. The AR10 wasn’t a big success, but it was the stepping stone to the AR15.

How the AR10 Gas System Actually Works

The AR10, and AR15 for that matter, are not a true conventional direct impingement system. It uses an expanding gas system, according to Eugene Stoner. Gas enters the bolt carrier, and the bolt has piston rings to contain the gas and move the BCG. The gas is then vented out the holes in the BCG. It is an ingenious design that combines the bolt and piston into one component, which made manufacturing simpler as well as decreased the weight of the rifle. And it’s ok if you still refer to the AR10/AR15 as having a direct impingement system. Just know it is not a conventional direct impingement system.

AR10 Compatibility Trap: Why These Rifles Aren’t All the Same

The AR10 was basically shelved when the AR15 was developed. In 1995, the ArmaLite brand was purchased, and the AR10B was reborn as a scaled-up AR15. In 2004, DPMS (Defense Procurement Manufacturing Services) introduced the LR-308 rifle, another AR10-style rifle. Since there was no U.S. government spec, there are two types of AR10 rifles: ArmaLite AR10B type and DPMS LR-308 type. The uppers and lowers are not compatible between ArmaLite and DPMS rifles. DPMS uppers feature a rounded back end and are compatible with a wide variety of aftermarket parts. This can be confusing for AR15 users since nearly all AR15s are compatible no matter who the manufacturer. ArmaLite uppers are slanted at the back of the receiver and use proprietary barrel extensions, bolts, and firing pins. If you decide to build an AR10, make sure the parts are the same type. Most AR10 manufacturers base their parts and guns on the DPMS pattern rifles. PSA, Aero Precision, CMMG, Bushmaster, and others all follow the DPMS pattern.

Caliber options in today’s AR10 aren’t limited to just .308 Winchester/7.62 NATO, though most AR10s are chambered in this workhorse caliber. Other calibers that are similar in length to the .308 Win. are available, like 6.5 Creedmoor and .243 Winchester.

Brownells BRN-10A: Shooting the AR10’s Cold War DNA

A few years back, Brownells went retro in a big way, offering complete AR10 and AR15 rifles and parts kits. The BRN-10A was a very close clone of the original Dutch-built AR10s. This is about as close to shooting an original AR10 as any of us will ever get. The BRN-10A is semi-automatic with a 20-inch heavy contoured, fluted barrel with the Dutch-style 3-prong flash hider. The barrel was manufactured by Faxon. The upper and lower receivers were made by FM Products and are built out of billet 7075-T6 aluminum. The brown furniture is polymer and mimics the original fiberglass furniture of originals. The rear sight is more like an AR15 A2 than the original AR10. The front sight is fixed and not adjustable. Like originals, the AR10 was meant to be used with iron sights. A scope cannot be mounted. Most of the operating controls are familiar to anyone versed in an AR15. They make you feel right at home. The BRN-10A feeds from a metal magazine. Any Armalite or DPMS will work. Forget Magpul Mags; they are not compatible.

Brownells BRN-10A Specifications From the Tested Rifle

Model	BRN-10A
Action	Semi-automatic
Barrel Length	20-inch
Barrel	Heavy contoured, fluted
Flash Hider	Dutch style 3-prong
Barrel Manufacturer	Faxon
Receiver Material	Billet 7075-T6 aluminum
Receiver Manufacturer	FM Products
Furniture	Brown polymer
Magazine	Metal magazine

BRN-10A Accuracy: Iron Sights Make This Interesting

I used a rest to get my dope at 50 yards and produced 5-shots that averaged across all ammo from 1.43 inches to 1.54 inches. A mix of FMJ and match was used: Aguila with a 150-grain FMJ, Hornady Match with 168-grain BTHP, PMC Bronze 147-grain FMJ, and a 175-grain Sierra Matching BTHP from Federal Gold Medal.

The AR10 had those familiar ergonomics. Unique to the AR10 originals is the trigger-style charging handle that doubles as a forward assist. I had to ensure the handle was well lubed because you can only get one finger on it.

At 100 yards, I burned through the last five rounds of the Federal match ammo as the AR10 clone got into its groove and easily placed all shots in the black. It is satisfying to shoot a 5-shot group at 100 yards that measures 3.5 inches with iron sights.

Modern AR10 Rifles: Bigger Optics, Better Parts, Same Muscle

There are many manufacturers building AR10s: Daniel Defense, Springfield Armory, Smith & Wesson, ArmaLite, Palmetto State Armory, Bushmaster, H&K, CMMG, and others. I like AR10s and have used S&W M&P10s in .308 Win. out to a 1,000 yards and Springfield Armory Saint Victors with thermal optics for pig hunting.

I had all of the parts in the shop to build a PSA AR10, which uses the DPMS pattern. The upper features an 18-inch A2 profile barrel with a mid-length gas system. I dropped in a Timney trigger, a two-stage that has a sinfully crisp pull. A Magpul PRS Gen2 adjustable stock that I forgot I had. I think the Magpul PRS stock is on its 3rd generation now. I prefer more vertical grips on my ARs, so I used a Strike Industries OMMG grip with a 20-degree angle.

A Leupold 1-6x24mm Patrol scope finished the build. I really like these LPVO scopes from Leupold. I can use it like a red dot on 1x and crack the magnification for longer shots. Plus it is not that heavy, since without the scope the rifle is already pushing nine pounds. There are some differences between an AR15 and AR10 build, so expect that if you decide to go DIY on one.

PSA AR10 Accuracy: The Budget Build Starts Punching Tight Groups

I lubed the BCG so it was nice and juicy, and used the same ammo to run the AR10 build. It devoured the ammo, chewing through without any issues. I’m always a little bit surprised at the accuracy out of inexpensive barrels like the PSA. Five-shot groups at 100 yards averaged 1.17 to 1.64 inches between the FMJ and match ammo. Average results with FMJ ammo were 1.63 inches for Aguila 150-grain and 1.64 inches for PMC Bronze with a 147-grain FMJ. The best I could get out of this ammo was 1.33 inches. Match ammo was a different story. Federal Gold Medal with a 175-gr. Sierra MatchKing BTHP had a best group that measured 1.09 inches and averaged 1.17 inches. The Hornady Match with the 168-grain BTHP had a best of 1.18 inches and averaged 1.22 inches. If I were measuring 3-shot groups, the PSA build was shooting sub-MOA. Not bad for an economy AR10 build. Running an AR10 is similar to an AR15; it’s just bigger and heavier.

AR10 vs. AR15: Is Bigger Actually Better?

The AR10 and AR15 serve different needs, and one is not necessarily better than the other. Opt for an AR10 if you want a more powerful caliber. AR10s make great hunting rifles. Check the AR10 off your bucket list, and that will be one Cold War 7.62 NATO combat rifle off your list.

AR10 Pros and Cons: What the Range Time Revealed

• Pros: Familiar AR ergonomics, powerful .308 Win./7.62 NATO chambering, strong hunting potential, impressive accuracy from the PSA economy build, excellent historical value, and broad modern configuration options.
• Cons: Bigger and heavier than an AR15, ArmaLite and DPMS pattern compatibility can get confusing, the original-style charging handle demands finger strength, and the BRN-10A’s original-style layout does not allow a scope to be mounted.

Related Reads From GunsAmerica Digest

• Today’s ArmaLite AR-10 Battle Rifle
• POF Rogue Sub-6lb AR10 Review
• Springfield SAINT Victor .308 Rifle

https://gunsamerica.com/listings/search