Weapon Trivia Wednesday: the AR-18

Today’s WTW comes to you courtesy of Groz. We are confident it will create a furor of pontification.  Mad Duo

Weapon Trivia Wednesday: the AR18

Of all the designs that sprang from Stoners AR-15 the arguably most influential but least known is AR-18.  Only produced inside the U.S. in small numbers and never adopted by any major military, its legacy is not widespread use but rather its influence on future weapons.  Many in the U.S. have only seen the AR-18 in movies or pictures of the IRA (Irish Republican Army).  Its unfortunate use by the IRA would leave it the nickname the “widow maker”, as that is how IRA allegedly referred to it.  However, its lack of notoriety was not because it was a subpar weapon, but more due to it being overshadowed by its older brother: the AR-15. (This despite being used by the Terminator to shoot the hell out of a police station.)

The weapon was designed by ArmaLite in 1963, intended to be a follow on to the adoption of the AR-15 FOW (Family of Weapons) by the U.S. as an alternative 5.56mm small arm.  The focus was for foreign sales to countries that would find the simplified construction (achieved by stamping) and cheaper overall cost to be preferable to the AR-15.


These differences in construction are very apparent when handling the AR-18, as the stamping and welding used in its construction give it a rougher appearance than the AR-15.   From the outside the two designs are rather similar in overall layout.  Breaking the weapon down is similar to the AR-15, as it maintains the two takedown pins to separate upper from lower.  Considering the differences between the two, the main difference is the AR-18’s utilization of a short stroke gas piston operating system.  Also the AR-18 uses a side reciprocating charging handle in lieu of the T-handle on the AR-15.  Note that the difference in operating systems also allowed the AR-18 to include a side folding butt stock.

The AR-18 magazine has a different cutout than the AR-15 and feeds from 20, 30, and 40 round magazines.  ArmaLite did not have the capability to produce the AR-18 in large numbers at their U.S. facility and the production was licensed to several foreign manufacturers.   Howa Machinery Co in Japan and Sterling Armament Company in the U.K. handled the majority of production.

Like the AR-15, the AR-18 design included several variants from its various producers.  The AR-180 was a semi-automatic only version.  Sterling produced a shortened version called the AR-18s with a 10.1inch barrel, which in some cases utilized a VFG (Vertical Fore Grip) built into the hand guard.  The AR-18s also featured a Krinkov-like conical muzzle device.  During the trials for the British SLR replacement Sterling also produced the SAR-87 which was a product improved AR-18.  Interestingly, Bushmaster produced the M17s, which were bullpup AR-18s during the adoption process that led to Australia adopting the Steyr AUG.  Singapore’s SAR-80 a licensed copy would see use during the Yugoslav Conflict in some Croatian units.

Although the AR-18 was never adopted as a standard issue rifle its legacy is how many designs it influenced, particularly in NATO countries.  The AR-18 seemingly competed against itself in the SLR replacement trials as the SA-80 internally was similar to the AR-18, and the SAR-87 was a variant of the AR-18.  In the Steyr AUG and G36 we both find many internal similarities like the guide rod assemblies.

When you’re looking at the AR-18 you cannot help but notice that the design contains many of the features so sought after in the current AR-15 aftermarket business today.  Side charging uppers have come to be used again (like LWRCI in the REPR, the 2 Vets Arms Bravo Rifle and other stand alone uppers).  Folding stocks, which were taboo for AR-15s for so long, are again being offered.  The craze over short stroke piston AR-15s is the most blatant of the AR-18 features which has crossed over.

So, taking all this into account, was the AR-18 a better platform than the AR-15 that overshadowed it?  Looking strictly at what the aftermarket crowd is demanding and with many premier military units using short stroke gas piston variants, that’s absolutely a  fair question to ask.

Let us know what your thoughts are on this question in the comments section of this article.

Further reading: the AR15 in Popular Mechanics, September 1963.

If you’re interested in further explanation of the AR-18 influence on the G36, Larry Vickers offers a detailed explanation in an episode of his show.


Mad Duo, Breach-Bang & CLEAR!

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