Accuracy with the Armalite AR-180 was more than acceptable, with…

Accuracy with the Armalite AR-180 was more than acceptable, with the open sights producing 1- to 2-inch groups at 50 yards with the ammunition tested.

Latley, “improving” the AR platform by developing piston-driven ARs in lieu of Stoner’s original gas impingement design seems to be taking over the AR rifle scene. So why the rush to modify the 50-year-old direct impingement design in the name of improvement? The cynical answer is that this is what gun designers/companies frequently do in the quest for market share via promising a better product. The more positive response is that the quest to improve a design never ceases. However, this is not a new phenomenon for the AR; it began at its inception in the early 1960s. Soon after ArmaLite, then a division of Fairchild, spawned the AR-15, they sold off its rights to Colt. ArmaLite almost immediately turned to improving the AR-15 design, all the while being careful not to violate any patent rights.

Ultimately, despite the AR-180’s positive features, the design was not widely adopted or popular with the public.

Arthur Miller, George Sullivan, and Charles Dorchester were tasked to create an alternative to the AR-15 in the form of the AR-18. This was accomplished by turning to a piston operating rod action combined with using sheet stampings in the manufacturer of the lower and upper receivers. The AR-18 was equipped with a now all-too-familiar short-stroke gas piston located above the barrel. The AR-18’s bolt carrier rides two metal guide rods that double as return springs; this is different than the AR-15 design, which has the bolt carrier in contact with receiver rails and return spring located in the buttstock. This not only allows for the AR-18/180’s stock to fold for a more compact form, but it also creates greater clearance and tolerance to foreign materials in the action—not to mention the short-stroke piston prevents dumping hot gases directly into the receiver. Further differences between the AR-18 and AR-15 are evident in the charging handle on the AR-18 being connected directly to the bolt and reciprocating with the action, versus the AR-15 charging handle design. The more conventional AR-18 bolt allows a user more purchase when operating the weapon during loading, malfunction clearance, etc.

The U.S. military purchased a handful of AR-18s in 1964 for evaluation before settling on the AR-15/M16. Instinctually, the gas-piston ARs appeal to many by the very fact that hot gases and powder residue are not dumped into the action like the original direct impingement (DI) design. Anecdotal evidence of bolt carriers being handled soon after long strings of fire and merely wiped down compared to their DI cousins reinforces this. Current proponents of piston-driven ARs point to greater reliability in adverse conditions and less reliance on routine maintenance compared to the DI operating method. These same arguments were put forth in the 1960s as well, though to no avail, as the AR-15/M16 quickly became entrenched in the military supply chain.


ArmaLite responded to the lack of military sales for the AR-18 by introducing a semi-auto-only variant of the AR-18—the AR-180 in 1969. Looking back and analyzing the facts at hand, this seemed a sound idea with great potential due to little competition in the civilian market for “black rifles,” especially one priced as competitively as the AR-180. Furthermore, Colt had its hands full with producing M16s, with little time to consider introducing the AR to the civilian market. ArmaLite was trying to offer a reasonably priced military-style semi-automatic rifle variant. Indeed, they were ahead of their time in the 1970s. We take such models for granted today without a second thought because of the number of ARs/AKs/G3s/FN-FALs we have on the market.

Load Comments
  • larry1355

    1-2 inch groups at 50 are not acceptable really. But it would not be the gun at all. I get 1 inch groups at 100 yd. with mine. It’s as accurate or more than my AR-15.

    • Hugo Mungus

      Stop trying to brag and claiming your a great shot! 1-2 inch groups at 50 is more than fine. And I doubt you can even do that. If you could? You would not be fake bragging.

      • Larry Wilson

        Not bragging at all….stating facts! I have been competing for a time….40+ years. My AR-180 will shot -1 inch groups pwith the peep sights. Fact…not a brag!! You maybe need to practice.

      • Larry Wilson

        Do you know what that little gold patch means?? I doubt you do!!

  • Lem Dickerson

    How to make the M-16, AR-15, mags fit the AR-180 is very easy. All it takes is to get an orignal mag to mark the position of the hole needed for mag retention pin. Then drill small hole& file it to correct shape and good to go mate.

  • While the article on the AR-180 was interesting, it did not say how to change the common M-15 magazines so they would work in my AR-180. Magazines for it are almost impossible to find and if there is a way of using the M-15 mags in it, it would be a big help to owners of the fine AR-180. If there is such a tool, where can it be found? Or who has magazines for the AR-180?

  • matt

    Nice article on a very underappreciated weapon. Kinda like my Steyr A1, biggest (only?) drawback is uncommonality, but a cult following at one time who felt it was best around eg best of AK and AR. If this exact rifle b /w rails, came out today it would be a huge deal. People were talking about the innovation of the Para AR folder and ZM weapons, Olympic even had that down a couple decades before. It is a shame the AR -180 was such a poor successor. Coming out during the AWB lacked important features and more importantly had the same problem regarding mounting optics…today almost essential to a fighting carbine. There is one aftermarket solution of better quality than rifle itself (the ones I encountered and handled all felt pretty cheap).Discontinued after the ban, right after IIRC and without getting a replaceable muzzle device or folder (again, aftermarket solution out there) seemed like all it had going for it was being done in a better packaging by the SU-16, Carbon 15 and to some extent M-17s (also shitcanned after the Sunset, by Bushmaster, this one filled the nice of Affordable bullpup). Maybe even the Mini 14 too if price point was of issue.

    5.56 ain’t my round anymore but if I were to ever own a carbine in such again, it would be this (distant second choice -the new 551A1) 1:12 and all…Actually I do want one but unfortunately it is not within means or priority.