The Largely Forgotten AR-18 Was Not a Stoner Design (Entirely)

Before discussing the Armalite AR18 design, let’s first look get some backstory. There are four characters that can evoke emotion in opponents of the Second Amendment: “AR-15.” It is perhaps the most misunderstood product of the 20th century, and gun control advocates have vilified the semi-automatic rifle by spreading misinformation and outright lies. The two letters “AR” — which are often erroneously described to stand for “assault rifle” — has become the scapegoat in every tragic mass shooting, while AR has also replaced “Uzi” or “AK-47” as the catch-all term to describe a modern semi-automatic rifle. 

The truth is that the AR-15 was just one of several designs that were created in the late 1950s and early 1960s that lead to the development of a category of firearms classified as “modern sporting rifles” by the National Shooting Sports Foundation (NSSF). While these rifles may resemble the actual assault rifles carried by military forces around the world, looks can certainly be deceiving. Of course, it should be noted that the early hunting rifles used in the 18th century were actually superior in quality and accuracy to the weapons carried by the soldiers of the era while hunting rifles of the late 19th and early 20th centuries were largely no different than the bolt action rifles employed by the military powers that fought in the two World Wars.

An early model AR18
An early model AR18, modified by unknown hands. (Photo credit unknown.)

By contrast, today’s modern assault rifles used by the military have capabilities, including select-fire and the ability to be equipped with grenade launchers, lacking in the civilian counterparts. All of that is beyond the scope of this installment of Throwback Thursday; this article is really meant to address a forgotten firearm in the AR line — the AR18.

Origins of ArmaLite

Understanding the history and development of the AR18 requires taking a step back. The ArmaLite Company only opened its doors in the post-World War II era. It was a new player in the American gun industry that had been dominated by such companies as Colt, Smith & Wesson, Winchester, and Remington.

All of those companies were essentially named after their respective founders, but perhaps George Sullivan didn’t see that Sullivan Arms was in the cards. Instead, Sullivan — who had worked as the patent counsel for the American defense contractor Lockheed Corporation (today Lockheed Martin) — founded his company as the ArmaLite Company. He also set up shop in Hollywood, California of all places.

The company didn’t actually begin a manufacturer of firearms, rather it was a weapons designer. That wasn’t itself all that odd, as designers such as John Browning and John Garand worked for the U.S. military and had their firearms produced directly at U.S. armories such as the original facility in Springfield, Mass.

In the case of ArmaLite, it received funding from the Fairchild Engine and Airplane Corporation — which soon became Fairchild-Republic, a major manufacturer of military aircraft. The chief architect of ArmaLite’s weapons was Eugene Stoner, who was a World War II veteran who served in the United States Marines Corps.

Stoner was clearly a forward thinker, but his early designs failed to impress. Among those was the AR-3, a firearm that could be seen as the great-grandfather of the AR-15 and other firearms to come. It still had a profile that was similar to the M1 Garand and other World War II “self-loading” rifles, but it utilized a forward-locking bolt with multiple lugs. However, it followed ArmaLite’s design principles to be largely constructed from lightweight materials. That included a receiver made of aluminum and a stock built of fiberglass.

Eugene Stoner with guns, 1958
Eugene Stoner, creator of the AR platform with some of his creations. (Image sours, Guns magazine, 1958)

“However, the AR-3 didn’t utilize the direct impingement that has proven itself through the years on the AR-15 platform,” explained Reed Knight of the Institute of Military Technology, and a colleague of the late Eugene Stoner.

The U.S. military reportedly didn’t see much potential with the AR-3, and instead, Stoner looked to other designs. After achieving success with the AR-5, a lightweight bolt-action takedown rifle chambered for the .22 Hornet cartridge that was used as a survival rifle by the United States Air Force, Stoner went to work on a new rifle for the U.S. military and the result was the revolutionary ArmaLite AR-10.

AR-10 Le-Boulanger.png
Another cousin of the AR18: this one was a select-fire infantry rifle chambered for the 7.62x51mm NATO round.

Stoner was submitted for rifle evaluation trials at the U.S. Army’s Aberdeen Providing Grounds in 1956 but was it was rejected in favor of the more conventional T44, a weapon being developed at the Springfield Arsenal.

The T44 essentially combined elements of the M1 Garand and M1 Carbine, while the AR-10 seemed almost too “futuristic” at the time. As a result, the T44 was adopted as the M14.

The M14 was the final weapon designed and produced at the Springfield Arsenal.

Despite not being selected by the military, ArmaLite continued to market its AR-10 on a small scale and the rifles were produced at its Hollywood facility. The limited production was nearly all hand-built and among collectors today, those rifles are known as the “Hollywood model AR-10s.”

“ArmaLite then sold the rights to the AR-10 to the Dutch arms manufacturing firm Artillerie-Inrichtingen (AI),” said Knight.

That company converted the designs to metric and produced what has been described as three versions that included the “Sudanese” model, which was sold to the government of the African nation; a “Transitional” model that incorporated features that improved upon the initial design based on Sudan’s experience; and the “Portuguese” version, which further improved upon the original model. A few other countries including Italy, Guatemala, and Cuba also purchased a limited number of the AR-10.

Development of the AR-15/M-16

Meanwhile, the M14 was in many ways not the right weapon for the new era of warfare, and Stoner was given another chance to refine the AR-10.

“It is fair to say that the AR-15 was essentially a scaled-down version of the AR-10,” explained Knight. “But it was also important to find a way to do it cheaper. That included stamped metal instead of cast parts.”

The history of the AR-15 and the adoption of the M-16 is well established, including how the design and patents were sold to Colt, and the weapon was adopted by the U.S. military beginning with the U.S. Air Force before it made its debut in the jungles of Vietnam.

Colt AR-15 Re-issue
Colt AR-15 reissue.

That could have been the end of the story, but Stoner wasn’t quite finished. He began to work on another weapon, the AR-16 — not in any way to be confused with the M-16. It was actually marketed towards emerging nations that had a limited industrial base.

“It was chambered in the 7.62x51mm cartridge as it was more popular at the time than the 5.56x45mm cartridge that NATO had adopted,” said Knight.

In order to facilitate the ease of production, the design of the rifle was kept relatively simple, which included few machined parts and a rotating bolt system.

“It used stamped steel parts, and because the rights were sold Stoner and his team couldn’t use the direct impingement system,” added Knight. “Instead, Stoner blocked the gas system and it had piston at the gas block. It had no operating rods and instead had two driving springs that closed the bolt carrier that included a single large spring in the buffer tube. However, this allowed the stock to fold to the side, which was desirable as it made for a more compact firearm.”

There had been plans to develop multiple versions of the AR-16, including a 9x19mm submachine gun and even a civilian sporting rifle. Instead, only a single carbine variant was made.

ArmaLite AR-16
ArmaLite AR-16.

Stoner then left ArmaLite in 1961 and served as a consultant to Colt before going to work at Cadillac Gage, where he designed the Stoner 63 Weapons System. The Stoner63 was a modular firearm that could be reconfigured as a standard automatic rifle, a light machine gun, a medium machine gun, or a solenoid-fired machine gun. 

Stoner 63
While the Stoner 63 showed promise, once again Stoner was a little ahead of the curve.

Enter the AR18

Stoner has been officially credited with having a hand in the AR18, but according to Knight, much of the design work only built on his concepts, and efforts to develop the AR-18 largely took place after Stoner had left the company. A new team of engineers headed by Arthur Miller (no relation to the American playwright) along with George Sullivan and Charles Dorchester began to work on adapting the short-stroke piston for a new rifle design.

The AR18 certainly had many of Stoner’s forward-thinking concepts, but it still went in a new direction as well.
As with the AR-16 it was meant to lower the cost that included a construction that utilized stamped and welded steel parts.

It was essentially a scaled-down version of the 7.62 ArmaLite AR-16 that included the use of the short-stroke piston to facilitate operation while still retaining the familiar rotating bolt of the AR-15/M-16, which were mounted in the carrier. However, the carrier rides on a pair of guide rods. 

AR-18 stainless steel stamped parts
Additionally, the AR-18 replaced many of the expensive forgings with stamped parts.

In many ways, the AR-18 was seen as a low-budget AR-15, and that even meant some issues in terms of reliability in dirty environments — which was already enough of a problem for the M-16 in the jungles of Vietnam. The use of stamped components required an increase in the tolerances, while a sliding spring-loaded stamped dust cover was added to offer protection to the receiver from debris.

M16 in Vietnam
M16 in Vietnam.

The use of all this stamped steel in a firearm was rather unique in the west. It had been pioneered by Nazi Germany in World War II with the MG-42 general-purpose machine gun and later the world’s first true assault rifle, the StG44. Likewise, the Soviet’s AKM — the modernized version of the AK-47 — utilized stamped steel, but it was something that the U.S. arms industry at large didn’t do. As a result, the AR-18 faced notable criticism over the use of its stamped and welded construction.

“Because it was made of sheet metal, it required forging that was necessary with the AR-15,” explained Knight. “However, the AR-18 was a robust gun. It was strong but wasn’t as light as the AR-15. It was also piston-driven, and it proved to be fairly reliable. It wasn’t as accurate as the AR-10 however, because the piton at the top barrel pushed on the side and that caused the barrel to vibrate in a non-harmonious way. That meant that when the bullet left the cartridge the piston’s vibrations were consistent and because it wasn’t uniform this impacted the accuracy.”

While it was developed to be an alternative to the Colt AR-15, the U.S. military didn’t express interest in the firearm. However, ArmaLite attempted to enter the civilian market with the AR-180 — a semi-automatic version.

The Same But Different

There were a number of similarities as well as differences with the AR-15 and the AR-18/AR-180. Among these was that the AR-18 included an operation handle attached to the bolt carrier that traveled with the carrier during operation. Additionally, the stock and fore-end of the AR-18/180 was a bit lighter than the AR-15/M16; while the buttstock was also hinged at the rear of the receiver assembly in an effort to ease portability in confined spaces.


There was a downside with the hinged stock, as it proved to be a weak point in terms of stock stability. In addition to the harmonics issue, this also resulted in reducing the overall accuracy of the AR-18/180.

The barrel length of the AR-18 was also two inches short at 18-inches, which resulted in a slightly more compact rifle compared to the AR-15/M-16, while the twist rate remained at one in 12-inch.

The magazines for the AR-18/180 featured a different cutout, while there was also a different latching mechanism. This meant that AR-15/M-16 and AR-18 magazines were not interchangeable, although AR-15 magazines could reportedly be converted to function with the AR-18.

One of the unique changes in the design was the removal of the iconic carrying handle on the top AR-15/M-16. Reports are that it was of little use in the field and complicated the sight adjustment and trajectory computations. Instead, an iron sight was mounted directly at the rear of the receiver, while a dovetail spot-welded to the receiver in front of the rear sight provided a way to mount a scope in ArmaLite proprietary rings. This was another concept that would eventually take on, but was way ahead of its time in the mid-1960s.

Limited Production And Variations

Much like with the AR-16, the AR-18 was put into limited production at ArmaLite’s machine shop and offices in Costa Mesa, California. Official numbers suggest that fewer than 1,200 of the military AR-18s were produced, while ArmaLite manufactured fewer than 21,500 of the AR-180s.

The company eventually cut its losses.

“It was made in Costa Mesa,” said Knight, “And I believe about 5,000 were made. Despite the efforts to bring the costs down, it was still too high. As a result, ArmaLite teamed up with the Japanese firm Howa, which produced the AR-18 under contract. But then the Japanese government outlawed them from the building of firearms.”

AR18 Howa
The AR18 Howa.

That is another story that is beyond the scope of this article, but the quick version is that Howa had produced weapons for the Japanese military during the Second World War, and after the war continued to produce weapons for the Japanese Self-Defense Forces. While it did produce hunting rifles and other civilian weapons, the Japanese government placed a restriction on the sales of military small arms to foreign countries. As a result, Howa was forced to cease production of the AR18 and also stopped making the civilian AR-180. Production was moved back to Costa Mesa.

ArmaLite then turned to the British Sterling Armaments Company, which produced various versions of the AR-18 under license.

“Howa built around 5,000 and Sterling built around 5,000. Those were imported in the 1960s and 1970s,” added Knight.

However, the licensing of the production to Howa and Sterling resulted in multiple foreign derivatives that were initially based on the AR18 operating system. Its design led to the development of the British SA-80, the Singaporean/British SAR-87, the Australian Bushmaster M17S, and the Japanese Howa Type 89.

Type 89 rifles
Type 89 rifles.

The AR18 and the New ArmaLite

Again the story could have ended for the AR18 years ago, but the ArmaLite brand was sold in 1996 to Mark Westrom, a former U.S. Army ordnance officer and inventor of a 7.62 NATO sniper rifle that built on the design concepts of Stoner.

“Westrom of Eagle Arms bought the name Armalite and got the patent and rights to build the AR-18 — and he built a number of the firearms,” said Knight.

Westrom rebranded his company ArmaLite, and in 2001 debuted a “new” version of the AR-18 for the civilian market, the AR-180B. It was a mix of the old with some new improvements for the 21st century. That included a molded polymer lower receiver instead of the stamped-steel original.

Note the polymer lower on this descendent of the AR18.

Additionally, the lower receiver was combined with the buttstock, which was fixed on the AR-180B, and in the process replaced the side-folding stock on the original. The AR-180B also utilized the AR-15 trigger group, along with the rear sight assembly, while the dog-leg cocking handle of the original AR-18/180 was replaced with a straight one, and the sliding dust cover was deleted. The result was very much a hybrid — but it also addressed the magazine issue, as the standard AR-15 magazines were now fully compatible.

Instead of being a hit, the new AR-180B sold poorly and the rifle was discontinued. The same problems that plagued it originally came back to haunt the re-launch. And yet despite the fact that this firearm has always failed to capture the attention of the mainstream shooting market, it refuses to die. There has remained a small, yet dedicated cult-following of the rifle.

It could be that some AR collectors see it as a missing item in their collection and the relative rarity of the civilian AR-180 has certainly driven up costs. On the high-end, a used rifle in excellent condition can fetch upwards of $2,500 while the class III military versions rarely come up for sale. A fully transferrable ArmaLite AR-18 with scope sold at Rock Island Auction in December 2019 for $23,000 — and that’s not counting the 20 percent buyer’s premium.

Finally, because this is a tale that seems to go on even after it seems to be over, as of 2018, the AR-180B made yet another comeback. Dubbed the WK180-C and manufactured by Kodiak Defence of Windsor, Ontario, it was another refined version that took elements of the AR15 and combine them with the AR18. It features ambidextrous controls and the ability to field AR-15 barrels, muzzle brakes, triggers as well as a variety of other AR-15 accessories and parts.


While there were plans to import the WK180-C into the United States, those efforts could not be dead as the liberal government in Canada has set out to ban all AR firearms. And with that, it could be the end of the story for the AR-18/180… at least for now. Something tells us that this is the gun that no one seemed to want, but yet seems to always make a return.

Peter Suciu is a Michigan-based freelance writer who regularly covers firearms related topics and military history. As a reporter, his work has appeared in dozens of magazines, newspapers, and websites. Among those are The National Interest, Forbes, and many others. He has collected military small arms and military helmets most of his life, and just recently navigated his first NFA transfer to buy his first machine gun. He is co-author of the book A Gallery of Military Headdress, which was published in February 2019. It is his third book on the topic of military hats and helmets.

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