Blog Of The Month:

For our February Blog Of The Month, we take a trip back to the early 1960s, after Armalite had sold the rights to its highly desirable AR-15 to Colt’s, and were searching for a competitor to their own design. The rifle designed by Art Miller to fill this void, itself an evolution of Stoner’s work on the 7.62mm AR-16, was the AR-18, the civilian model of which was called the AR-180. Dedicated to this fairly unsuccessful but highly influential weapon is, a website that in its own words seeks to become “the central depository for AR-180 information.”

96476BF0-38FD-4F92-B840-453E916E9EDB_zpsrpsxbddj1’s author’s Costa Mesa AR-180, the rifle that started it all.


The site is only a couple of months old itself, but already contains some interesting information on the AR-180, including different manual variations, scope information, and a project to build a short-barreled AR-180 pistol, patterned off the AR-18S.

The AR-18, though it was a design that prioritized expeditiousness of manufacture uber alles, still was highly mechanically sound, and probably would have achieved greater success had it not been beaten to the market by other designs. Even so, it laid the mechanical foundation for later designs like the G36 and Remington ACR, and so has an important place in the history of modern small arms. promises much more information on this interesting and significant rifle, and is therefore our February Blog Of The Month!

Nathaniel F

Nathaniel is a history enthusiast and firearms hobbyist whose primary interest lies in military small arms technological developments beginning with the smokeless powder era. In addition to contributing to The Firearm Blog, he runs 196,800 Revolutions Per Minute, a blog devoted to modern small arms design and theory. He is also the author of the original web serial Heartblood, which is being updated and edited regularly. He can be reached via email at


  • d_grey


  • Gene Stoner and L. James Sullivan were already gone from ArmaLite when work began on the AR-18 in 1963. While the AR-18 was derived from Stoner’s previous 7.62mm AR-12 and AR-16 prototypes, the majority of design work on the AR-18 was done by Art Miller.

    • That’s what I get for doing a writeup without consulting references! Thanks for the correction , Daniel!

      • I have started my version of the AR-18 history many times in my head but with out original source material I have yet to put anything down on paper. Fortunately I have met with someone who has reams of it and is willing to share with me so I can get my facts straight. I can’t tell you how many times I have read the the AR-18 is a Stoner design and that is simply not the case. Are his previous designs an influence, yes. But that is all.

        • Small Arms Review had an excellent interview with Art Miller several years ago. Alas, I don’t think that it is available via their website at the moment.

        • BR, I’m behind you 100% on the AR-18 history. That would be a great read, I’m sure!

  • Pete Sheppard

    Bare-bones simple firearms have always interested me, and the AR-180 tops the list! If only it took AR15 mags…

    • Anonymoose

      Back in the day when Sterling produced AR-18s for export, they made 30- and 40-rounders that were compatible with both AR-18s and AR-15/M-16s.

    • M

      I thought they did? or at least used modified AR-15 mags?

      • Pete Sheppard

        The AR18(0) uses a slot cut on the right side of the mags for its mag catch. I had read that that was the only difference, though.

  • morokko

    “I was stopped by a soldier, said he, You are a swine,He hit me with his rifle and he kicked me in the groin,I begged and I pleaded, sure me manners were politeBut all the time I’m thinking of me little Armalite.”
    I just could not help myself…

    • Nehemiah Sconiers

      Love that song. haha “Six hundred British soldiers whe had lined up at his feetCome out, ye cowardly Fenians, said he, come out and fight.But he cried, I’m only joking, when he heard the Armalite.”

      • William M Butler, MSG USA ret

        What do you have against the Irish? ( Fenians)

        • Nehemiah Sconiers

          I am not sure if you noticed, but both sets of lyrics are making fun of the British soldiers in Northern Ireland. Fenians is just part of the lyrics of the song, both sets of lyrics are from the same song “My Little Armalite”, which is a Pro-Irish, Pro-Unified Ireland, Pro-IRA song. They mention the repeated use of an armalite rifle, so he saw it fit to post those lyrics, and i saw it fit to add another section mentioning the rifle. I have nothing against the Irish, hell I have Irish blood running through my veins. So before you go accusing and jumping to conclusion, read a little more and maybe do a little research.

  • schizuki

    “I don’t wanna spend the rest of my life, looking down the barrel of an Armalite…”

    • Gordon Sumner

      …I don’t want to spend the rest of my days
      Keeping out of trouble like the soldiers say…
      (You beat me to it)

  • Cap’n Ball

    The AR-18/180 is an excellent design and (not trying to start a flame war) really better than the AR-15. The designers wanted something that was easy and simple to manufacture and maintain in the field, like the AK. It’s a gas piston design, there’s no stupid buffer (so you can have a folding stock), and no need for a forward assist. It’s a snap to field strip and has a simple, robust scope mounting system. But it never got the refinement and development the AR-15 did (and needed). I’ve got one and love it, but parts are increasingly hard to find. Too bad.

    FWIW I’m ex-Army and have used the M-16 extensively.

    • Cap, let me come in from the other side,

      Here are the ways I identify the AR-15 as being a better design than the AR-18. Note that I am not making an overall assessment of the two designs (I like both), but that I think these positive aspects of the AR-15 versus the AR-18 may be easily overlooked:

      1. The AR-15 does not waste mass by using a reciprocating short-stroke piston. Short-stroke pistons have some advantages, but they utilize the mass of the piston inefficiently, as it is not available for feeding and locking. This means that, even if slightly, a DI design will be lighter than an equivalent “classic” short-stroke piston design.

      2. The AR-15’s forged aluminum construction is quicker to make, and more durable than stamped steel, while being at least as light.

      3. The AR-15 has a modular moving mass, which has led to it proving extremely adaptable and versatile.

      4. The AR-15’s mainspring is much closer to the axis of force during feeding than the AR-18’s, reducing friction during critical parts of the cycle.

      5. My gut feeling is that the amount of stamping and welding precision needed for the AR-18 is undesirable, and will lead to a higher part rejection rate and possibly a higher overall malfunction rate in accepted firearms than the simpler forging method of making AR-15 receivers. I don’t have any data backing this up, though. It’s not unreasonable for me to think this, however, given that the AR-18 was designed for easy license “production” (really assembly) over all else.

      6. The dual welded guide rod design of the AR-18 I think has proven problematic. The British had problems with it in the L85 program (granted, not only did they make it worse by adding a third guide rod which also had to be parallel, but they had problems doing just about everything in that program, including make barrels), and almost every successful AR-18 derivative has dispensed with it, in favor of a single guide rod that isn’t welded to the retaining plate. The AR-15’s carrier guide system, in comparison, is almost foolproof.

      7. I don’t have the exact numbers on hand, but I am fairly sure the AR-18 has an inferior mass ratio versus the AR-15. A modern rifle should have a mass ratio of about 5 to 1.

      I hope this was helpful; feel free to respond!

      • John

        Anyone whose ever had their AR-15 bolt stuck inside the buffer tube would disagree with your foolproof assessment.

        • “Almost” being the key word. Bad manufacturers can screw up anything.

          The guide rods on the AR-18 are downright tricky to get right.

      • Esh325

        That’s all very ridiculous if you ask me. Machining a reciever is quicker than stamped sheet metal? The whole point of stamped receivers is that they are quicker and cheaper to fabricate than machined receivers. Not as durable? Prove it. I haven’t heard of any issues with stamped metal recievers considering one of the most durable firearms in the world the ak is stamped. The only thing i think you said that made any sense was that the ar15 is more modular only because it’s been around longer and more developed.

        • The AR-15 uses a forged receiver, not a machined receiver.

          Ask any owner of the AR-18 about the stock latch, if you want to hear about durability.

          It took ten years of debugging by one of the most experienced nations at firearms stamping to get the AK’s stamping to where it is now, so the AK probably rises to a level above other stamped guns.

          I didn’t say the AR-15 is more modular, I said it had a modular moving mass. That’s important for keeping the design competitive, and reliable in multiple configurations.

          Mass ratio is explained in the hyperlink.

          • Esh325

            A forging which is machined no matter how you spin it. The Germans perfected stamping from early on. The notion that stamped receivers are in some way not durable is false. And there isn’t any evidence I’ve read that durability of the stamped reciever was a problem on the ar18. Modular moving mass?

          • My take on this is that you simply can not compare what is basically a prototype gun (AR-18) to another that has had 50+ years of testing and design improvements (M-16). You must also take in to consideration what the manufacturing infrastructure was in the early 60’s. Was it cheaper, when production scaled, to forge and machine each unit or machine the stamping dies once and then punch out the parts? Machine tools were manual and run by highly skilled and highly paid people. Stamping parts on a punch press could be taught to almost anyone in a few hours time.

            The appropriate comparison in my mind is the AR-18 to the Prototype AR-15 that the government tested before it’s adoption. Or a modern comparison would be the M4 to the MagPul Masada/Bushmaster ACR. That is the modern version of the AR-18 in my opinion.

          • Esh325

            You have a point. Would it be cheaper today to mass produce an ar18 versus ar15? If I coukd warrent a guess I would say yes. I think the reason most rifles today don’t have stamped parts anymore is because the climate of the world has changed. There’s no chance of an all out war scenario like there was in the Cold War where you needed to have designs that could be pumped out while bombs were exploding outside the factory. I suppose the howa rifle the japs use is quite close to the ar18

          • Are you objecting to the existence of machining operations in the construction of the AR-15 at all, or…?

            Your argument seems to be that stamping is always quicker than everything else; it’s not. The MP-44 is a great example of something with compkex stamping operations. The AR-18 isn’t anywhere near as bad as that, but it does require a good deal of stamping and welding operations, especially in the lower. None of these are particularly hard to do, but unless some awesome CNC welding machines were used (going against how the AR-18 was designed), I see the AR-15 receivers taking less time to complete, absolutely.

            Stampings may be durable or not durable; it greatly depends on their metallurgy and construction. The AR-18’s receiver is a box, which isn’t a tremendously strong or weak shape. The AR-15’s receiver is more of a structurally reinforced tube, and the lower is a pretty heavily reinforced aluminum box. I don’t feel I am stepping out of bounds by judging the AR-15 to be essentially structurally more sound, though how and at what point

          • Esh325

            Not all the time, just most of the time. There is a reason why there was such a large shift from machined/forged parts to stamped ones during ww2. It’s ususlly quicker and cheaper to make. It’s possible the ar reciever might be more durable, but not really much to back up that claim than just assuming.

          • There’s a big difference between forging a Garand or Mauser receiver, and forging an AR-15 upper and lower.

            And besides, I did not mention cost, only time of manufacture.

          • Robert Kaschner

            Stamped parts USED TO be quicker to make. But not since the rise of the CNC machining center. Nowadays anything that requires multiple steps (like stamping then welding then fitting) takes much longer than machining forgings to perfect specs in a matter of minutes.
            Also, I’m pretty sure when the germans had free labor for building their rifles, they cared more about cost of material and overall output than man-hours required for manufacture.

          • wclardy

            Robert, when you get to large-volume production, stampings still are faster and cheaper. It’s just a matter of how many units it takes for the lower per-unit incremental cost to offset the initial capital cost for for the stamping die/mold — and additive manufacturing (a.k.a. 3-D printing) is rapidly reducing die costs.
            As to the folding and spot-welding, you can ask Detroit, Toyota, Honda and whomever about the current state of the art on shaping and spot-welding heavy-gauge sheet metal.

          • Steve Truffer

            No disagreement on the Western bits (I defer to your knowledge on them), but one little niggle about the AK.
            I’ve spent multiple years examining the AK’s design and evolution. Something that I’ve noticed about the early designs was that the was very little debugging.

            The Type 1 AK reciever has next to no rivets. The trunnion was secured via slip-fit and what amounts to crimping – a satisfactory solution to Kalashnikov’s earlier designs utilizing the 7.62×25, but wholly unsuited for the 7.62×39. my perusal of various russian boards showed a couple prototypes made after the milled reciever, and mostly seemed to be experimenting with methods of securing the trunnion- a series of ridges to increase bearing surface area, and configurations of rivets (which were finalized as the AKM pattern) I wish I had the presence of mind to save them, some looked like Koborov got ahold of them.

          • Interesting. Details about the AK aren’t really my area, so I defer to others regarding them.

          • go4it

            AR-15 / M16 receivers – Upper AND Lower – are forgings “in the rough”. They must be “finish machined” to be functional. I cannot think of ANY “forged” item ready to use “as-is”. Well, except for a paper-weight ..

  • Jack Handsy

    Can we get Jumplf to hop in here to provide a lengthy diatribe telling us how terrible the AR180 is and how any counter opinions are wrong? If he’s taking the weekend off, are there any other negative Nancies willing to step up to the peerless pulpit of the Internet arms expert?

  • BigRix

    Thanks for the Blog of the Month Nathaniel, It has been a true pleasure putting this blog together and I hope to bring some more interesting articles soon.

  • hal

    Way back when my beard was brown I was looking to buy my first .223 long arm and was eying both the AR-15 SP-1 Colt and the AR-180. After looking over both rifles I bought the Colt AR-15 because it looked to be a better designed and assembled rifle. Mind you I had very little experience with firearms designs, but I did have the engineering knowledge and so the AR-180 with its sheet metal construction and visible welds, appeared “unfinished” as if it were made in a less advanced country. The AR however has aluminum castings that were finely machined with tight fits and clearances.The AR-180 was selling for over 500 bucks and the Colt AR was 425 dollars + tax. I was about 23 at the time and that was a whole lot of greenbacks for a guy just married with a house payment, and aside from the Colts better manufacturing, I could buy a lot of ammo for $75. The year was 1978. As the years rolled by and my collection of arms grew, there were three sheet metal rifles that I wished I had purchased before they stopped selling here. They were the AR-180, the SIG-AMT and the HK 91 and 93. Luckily I snagged a new Belgian made original FN-FAL 50.00 in 1987. I wonder what ever happened to the tooling for the AR180 ? I know that Howa in Japan was making AR-180’s for a while but they eventually stopped, likely to the fact that no government would buy them. Thanks for the article..It illuminated brain cells that have been dark for many years.

    • wclardy

      Isn’t that 4 sheet metal rifles?

  • Scott P

    I would be in for one if took the readily available AR mags. Too bad the AR-180B was a substandard clone or so what I have heard from people owning them compared to the original.

    • I owned an AR-180B once. I agree it’s not up to the standard of the originals.

  • William M Butler, MSG USA ret

    You guys are a bunch of turds in a punch bowl. It is what it is. 18 didn’t happen, although a noble effort. 15 is the state of the art, today. Get over it! If you have and like an 18… more power to you. I think you are doing what is correct for you. But, get over it, you are wasting to much energy making up something that is not reality. Have it, shoot it, enjoy it. move on to something that means something important. How about them PATRIOTS! ! ? Just as real as a rifle that didn’t happen. Love you man, get a life. the world needs your mind to make it better.

    • I really don’t think that comment was necessary.

    • Panfried

      Speaking of punch, all of the kool-aid is gone… but I think I know where it went,

    • schizuki

      Yep… that’s a Pats fan.

  • M

    Something I kinda noticed:
    US adopted Krag-Jorgensen but Mauser refined the bolt action and the Mauser 98 action became a gold standard and proliferated around the world
    US adopted the 1911, then Browning/Saive refined the automatic handgun and the Hi-Power became a gold standard/proliferated around the world
    US adopted the AR-15 platform, Stoner/Miller refined the design and AR-18 derivatives became a gold standard and proliferated around the world (G-36, SA-80, SAR-21, ACR, FN2000, etc)

    • I don’t know that I’d consider the AR-18 to be a “gold standard” of rifle design. Further, two of the designs you cite are not related to the AR-18 (SAR-21, fixed piston, two lug bolt, F2000 is an AUG derivative). The AR-18 has been widely adapted, yes, but as a basis for design it’s certainly not as popular as the AR-15.

      I think you’re seeing a pattern that’s not there, I guess.

      • M

        The reason I said it was a gold standard is that new weapons that are currently coming out have an either AK-esque fixed gas piston design, or an AR-18 esque short stroke design. I certainly see it in the new Polish MSBS and Bren 805

        The AR-15 the way I see it, is an AR-15 (i.e. I don’t know if any manufacturers have taken an AR-15 platform and repackaged it as a different rifle like how a G36 is an AR-18 redesigned)

        • That’s not entirely true. Many weapons are also tappet operated, and a substantial number of DI designs are still being released (counting something like the CMMG MK 47 as “only” an AR and thus dismissing it as not a new design doesn’t really convince me).

          It’s interesting that people notice designs that recycle the 7-lug bolt and short-stroke piston of the AR-18, considering neither of those features are unique to the AR-18. Indeed, many short-stroke AR-15 derivatives have been developed in the past few years, but one could as easily attribute that to the success of the FAL, Vz. 58, or SKS as the AR-18. Designs like the ACR, MSBS, and S805 don’t share much with the AR-18, besides their gas system. In fact, all three of those designs incorporate gas regulators, so they’re arguably more closely related to the FAL than the AR-18.

          Not to lambaste anyone, but I think some of the comments here are a good example of how when a new oprod design is introduced that isn’t explicitly an AK derivative, folks tend to label it as an AR-18 derivative immediately.

          Examples: The AUG and SAR-21 were both mentioned as being AR-18 derivatives. You could maybe argue the AUG is a heavily mutated AR-18, but its bolt carrier/guide rod arrangement is still wildly different than that of the AR-18, and it utilizes a fairly large tappet piston with gas sealing rings and a return spring (so it’s sort of a hybrid short-stroke/tappet). Clearly not a straight AR-18 derivative at all. I don’t know why folks think the SAR-21 is related to the AR-18, it almost couldn’t be more different (within the scope of rotary-bolt 5.56mm rifles, at least!). It has a two-lug rotary bolt with a fixed direct impingement operating rod; I’d say it owes more to the Garand than anything else.

  • I don’t see how the AUG is a straight AR-18 derivative. It has a wildly dissimilar bolt carrier design and is tappet operated, with sealing rings and everything.