Video: USAS-12 Combat Shotgun

The USAS-12 is one of the few fully-automatic shotgun to actually be put into mass production, aside from Russian 12ga AK conversions. It was designed in the late 1980s based on the work of Max Atchisson and manufactured by the Daewoo conglomerate in South Korea. About 30,000 were made in all, mostly sold in Asia for police and military use. Importation of semiautomatic examples into the US was hindered by the Treasury Department determining them to have no sporting purpose, and thus to be legally classified as Destructive Devices under the NFA.

Edited to add that a commenter on Youtube pointed me to a copy of the original marketing film for the USAS-12. You can see it here:


  1. Really? No sporting purpose? I can’t tell you how many times I’ve been duck hunting and needed 10 rounds full-auto.

    • Exactly USAS- Universal sporting automatic shotgun, NFA folk tut! No sporting purpose indeed, the clue is in the name duh.

  2. Used an AA-12/Double-A 12 a few times and wish I could have brought it home. All of Atchison’s guns are ground-breaking as far as I am concerned. The older models, and most certainly this one as well, are a bit weighty with the drum magazines but are devastation on the front end. One of the loads we used were steel ball bearings about a quarter inch in diameter and they would shred a car, and everything inside of it, in very short order. These guns were and are great for close-in ambushes and against mass assaults as well as close-quarter urban situations such as vertical assault structure clearing (top-down assaults) in multi-storied buildings. Wish I had the green to purchase this one, but am too old to “play the game” now.

  3. It is painful to watch you use the wrong size screwdriver on these screws, especially considering the scarceness of the weapon.

  4. Am I right to assume that the ejector can be inserted into the hole on the opposite side of the trigger assembly to change direction of ejection?

  5. This is a robust weapon, probably on par with SPAS-12; no wonder they never replaced usual small bore assault rifle. It would be interesting to see it side-to-side with Saiga 12.

  6. “fully-automatic shotgun”
    I doubt in its feasibility, it has advantage over self-loading shotgun in that it can fire more lbs of lead/second but how many times you need to fire faster than self-loading shotgun can?

    Due to law, in Russia shotgun license is easier to obtain, this lead to inventing of this weapon: (despite at first glance it looks similar to SKS it is not SKS, BTW: it is shotgun from US point-of-view?)

    • I don’t know, in jungles it might be alright… Have you not watched the fantastic 80’s promotional video, he he.

    • Like most efforts to “improve” the shotgun as a close-in tactical weapon, the USAS-12 (and its French counterpart, the SPAS-15) fails on several factors.

      First of all, it’s as big and heavy as a SAW, but lacks its range capability. It also cannot supply sustained fire; sorry, but we learned the drawbacks of box magazines for the SAW or equivalent with the BAR sixty-some years ago. It is also limited in the amount of ammunition that can be carried by the weight and volume of the shotgun rounds (a fault it shares with conventional shotguns). And frankly, box magazines or drums that size are a pain to deal with. (NB the “AA Drum” for the Bren- there’s a reason it was rarely used in the field.)

      It can’t practically be fired prone, even with the drum. Its weight cries out for a bipod, but none is provided.

      In short, its only major advantages (?) are full-auto capability and “looking cool”.

      I’m dubious about the full-auto being controllable by anyone who doesn’t have Ian’s experience. I’m pretty sure I’d have problems, and I’ve put in my share of trigger time on everything from M2HBs on down, especially BARs and M1921/28s. The average citizen-soldier or police officer -even ones I trained- probably shouldn’t get involved.

      Rather like the whole Objective Individual Combat Weapon aka XM26 project, the USAS-12 type shotgun is what Cooper called “an ingenious answer to a question nobody ever asked”.

      /just imho



      • I suppose that the “awful” Chauchat outclasses the USAS-12 in range and in ammunition capacity and in being controllable when switched to full-auto. Given a choice, I’d rather take an MP-40 over the USAS-12 just for the fact that the former is probably just as destructive without requiring a new set of tools for maintenance. Since when did anyone need fully automatic shotguns against ducks? Would the auto-shotguns be any better at downing ducks than a platoon of Japanese holdouts with Type 99 Rifles fitted with anti-aircraft lead bars? I doubt it, but did I get anything wrong? SAY SOMETHING!!!!

        • I’m sure one loaded with No. 6 power piston loads would be a “market hunter’s” dream. I’m not exactly sure the game warden would approve, though.

          I suppose it would make an efficient home defense gun (which I believe is what the Saiga is sold as), but on full-auto indoors your homeowner’s insurance agent is not going to be happy with you afterward.

          About the only practical mission for this beast, militarily speaking, is the same as the original purpose of the SPAS-12; a “door gun” for a C-SAR helo crew chief, to deal with “locals” trying to get a downed pilot before he can be hauled aboard.

          Hung from the top of the doorway on a couple of dummy cords, it would be a fast way to deliver beaucoup’ buckshot or flechettes into a hot LZ.

          Myself, I’d rather have a GE Minigun for that mission. 6,000 rounds per minute of 7.62 x 51mm NATO goodness.

          And I don’t have to worry about changing magazines in the middle of a debate, so to speak.



        • Chindits… That full length guide rod lark could allow you to offset the barrel/bolt from the rest of the mechanism, sort of tilted Swiss sniper rifle style. The guide rod remaining “straight” so the trigger remains parallel with the shooter, with the barrel “cockeyed” doing this would enable you to turn it upside down so it is top loading thus ejecting out the bottom. Fit a Famas style bipod mounted forward of the mag so it extends down past the hand guard when extended. Jungle ambush gun, lie prone, low to the ground, mouth closed because of spiders, hidden behind some big leaves- Moveable Claymore bbbbbang! It might look a tad “Japanese” i.e. Odd, but it might accentuate the perceived benefits of an automatic shotgun in said circumstances perhaps. The guide rod would probably help align this cockeyed configuration for reliability, whilst keeping the guns overall operation the same. The mag would be offset to the left, as would the hammer in it’s housing, you could see a set of sights on top of the barrel with your right eye. This would allow clearance of the guide rod/piston etc for downward ejection with the bolt face rotated to correspond, the receivers tilt would allow a modified stock to act as a cheek piece ending with a straight down butt plate. The cocking handles ambidextrous lark would become defunct but it would still act as a bolt hold open, with just a single ejection port in the area of the carry handle currently. Nipon! Fujitsu! Mr Sparkle!! Japanese there in Burma with the modified version, they like it.

      • “SAW”
        Under this i should understand FN Minimi or something else?

        “hot LZ”
        What that mean? So far I know LZ = Luftschiff Zeppelin, but this does make no sense.

        “And I don’t have to worry about changing magazines in the middle of a debate”
        Or maximal range, as 7.62x51mm range is many times bigger than shotgun.

      • Xm26 might be ok for neutalising suicide bombers hopefully shooting them with shotgun slugs would impart enough shock to prevent them from detonating the belt before dying, think I read in Iraq 5.56mm didn’t kill a bomb ninja quick enough apparently and it exploded splattering the market in a devastating manner. Read it somewhere, think they said it started jabbering to God prior before connecting the leads so they knew what was happening so they shot it but it didn’t prevent the connection being made.


          “At the present time small numbers of XM26 LSS shotguns are issued to US troops in Afghanistan, and, according to available sources, these weapons are well received by troops who used them. It is believed that XM-26 will be compatible with the next US assault rifle, the XM8.”

          You’ve gotta like that! I dislike the XM8 personally through, ewwww yuk.

          • Must be an old post, as the XM-8 project died ten years ago when they found out that the “composite” (plastic) structure tended to melt with sustained fire, and the Lazer Tag-style sliding stock was too fragile for service use.

            H&K lost a chance to re-equip the entire U.S. military with rifles when their “Lazer Tag modded” G36 failed the Ordnance tests. Still, a lot of armies have either adopted the G36 or, in the case of the Mexican army, produced their own semi-knockoff of it;


            I’m wondering if the G36 isn’t one of those weapons you hope the other guy tries to use on you. On the principle that your chances of handing him back better than he delivers are improved.



        • See “AAI Serial Bullet Rifle” from the U.S. Army Advanced Combat Rifle program. Also the TRW “Low Maintenance Rifle” of the early 1970s. Or for that matter, any modern military rifle with a three-shot burst setting.

          The SBR was supposed to use a special 5.56 x 45mm loading with three 22-grain bullets, one behind the other. When that didn’t work, they tried a three-shot burst control.

          The TRW LMR also had a triburst setting but no full-auto setting; it was intended for “indigenous troops” and was designed to be both “idiot-proof” and to conserve ammunition. It’s mainly notable for looking like a cross between an MG-42 and a FG-42.

          Even earlier, there was the Hughes Lockless Duplex Assault Rifle and LMG;

          That tried for a home run with both an early form of Plastic-Cased Telescoped Ammunition (PCTA) and dual bullets in train one behind the other. At least one firing a true caseless round was built, as well.

          For some reason, it’s always looked like a BAR to me, specifically the FN version.

          If you go way, way back, you’ll find “multiple-ball” cartridges for .44 and .45 caliber revolvers intended to do more or less the same thing in a hot fight with the Comanche- or in a saloon brawl;

          At least some of these were actually produced and sold commercially in the 1870s to 1890s.

          Firing more than one projectile does increase your chances of obtaining a hit. But some of the methods proposed to achieve it can be a bit involved, to say the least.



        • “Cool” doesn’t cut it at 0200 in the jungle- or a back-alley in Columbus.

          And forget it when dealing with M.E. engagement ranges. Even M855 comes off second-best there.

          I might add that getting this beast in and out of a passenger vehicle is a major pain. “arms” and “legs” everywhere to jam on doors, etc.

          Even the pain-in-the-drain SPAS-12 was more useful than this one, real-world.

          Myself- Remington 870 or Mossberg 500. Simple, reliable, compact, and if you can’t solve the tactical problem with five to eight rounds of slug and double-ought, you needed something more serious to start with.



          • “… you needed something more serious to start with.” I usually had more than one resource to choose from; the major ones being a AA-12 (seldom), the M-40 (frequently), the M-14/Stoner (sometimes)or a M1919 Browning light machine gun with a by-pod and shoulder stock better known as the 1919A6 (specialized ambush weapon). Each had its strong and weak points but invariably at some point one always found himself muttering, “Man, I wish I had my XXXXX instead.” or more frequently,” I wish I were somewhere else right now!”

  7. I really like how’s it put together, and the mechanism very impressive, utilitarian. If you put a tube magazine on it, and wood… Non pistol grip, Saiga type “sporter” stock. Perhaps it could be remade in semi auto, and not be banned.

  8. First: “ … it can fire more lbs of lead/second but how many times you need to fire faster than self-loading shotgun can?”
    The problem with, say, an 870 Remington pump, is capacity; if you have a standard barrel and standard tubular magazine, you have five (5) shots and it is SLOW and cumbersome to reload. With a full-length barrel and tube magazine extension you can get 8 round in. It takes about 2-3 second per round to reload from a belt. I use one made up of three sections of a WWII M-1 clip belt slung like a bandoleer across my chest. It will hold three (3) rounds per pouch for a total of 45 rounds and weighs exactly 6 pounds. The AA-12 would, if memory serves, hold 25 rounds in a drum magazine and magazine replacement time was 3-5 seconds. Therefore, the effective rate of fire was and is very heavily weighted toward Mr. Atchison’s weapons. With the full-length barrels for an 8-round capacity the weapon becomes unwieldy in confined situations like urban clearing operations conducted mostly inside buildings. A chopped 870 can be reduced as far as a 13” barrel. With a folding stock it becomes an even more manageable weapon in close quarters.
    Next: “I don’t know, in jungles it might be alright…” is not entirely accurate. While loads of Double-Ought or specialty rounds are very effective at close range in heavy vegetation, they are no slouch in the accuracy department with slugs. My oldest 870 has a 20¼” barrel with a standard stock and a 4X scope. With it I used to (when I was younger) put consecutive five rounds groups of Remington slugs through the bottom of a coke can placed end-on at 35-45 yards from a rest across the hood of my truck. I could easily hit a medium-sized (25-50 pound) hog in the head from a distance of 50 yards. HOWEVER, I had swaged a 4” long 1.5° “choke” in the end of the barrel like I put in my pellet rifle barrels of my hunting rifles. If I had some way of putting a “paradox rifling” in it the slugs would do better but the shot patters would develop an erratic spread to the determent of their effectiveness in combat. For additional versatility you might “Google” the terms “specialty shotgun slugs,” “specialty shotgun shells,” and “exotic shotgun ammunition” as well as variants of that theme. As an example of what is out there, see with particular attention to the “Macho Gaucho” “chain-shot” slugs and the “Armor Piercing Incendiary” that punches through a steel beam … and note the accuracy at range as well. There are also rounds designed to punch through concrete block walls, penetrate engine blocks and etc. Pairing these with the USAS-12 or the AA-12 makes it a quite formidable weapon indeed!

      • “I ask about self-loading shotgun not pump-action i.e. repeating shotgun.” Same principal; restricted ammo load and slower loading equals “problems.” Also, the slide-action (a.k.a. “pump”) has proven, at least in my actual combat experience, to be more dependable under traditional in-field use. “Self-loading shotguns with box-magazine exist, like MP-155K.” True, but I have never run across one with a 20-25 round drum magazine. If it is a 10-round clip the capacity is still only equal to or less than half that of a drum which equals out-of-service/action time in a close-in combat situation where fractions of a second count. In the final analysis, the preferences of the shooter is of paramount importance; if you are more comfortable with a katana than a mini-vulcan, then that should be your weapon of choice. But in a close-in ambush situation, whether urban or not, the faster you terminate ALL targets the more probable it is that you sill go home in the passenger compartment instead of the cargo hold. Of course, these are my personal opinions and not finite truths. Everyone has the right to their own beliefs.

  9. The company name is pronounced ‘Day-ooh’ (I.e. silent ‘W’). I only know this because they sold cars over here in the UK.

  10. Ian
    I believe the early Atchison guns and the later AA-12 were slam-fire constant-recoil weapons like the Singapore Ultimax 100. With an internal hammer this gun does not seem like a slam-fire type, but does it have the extra long bolt travel to keep the recoiling carrier from hitting the back of the receiver during firing?

  11. The chap who made the Jackhammer did so because he figured it would have been handy in the Korean war, and the Koreans thought this was ok and it sold in Asia perhaps tbe concept is just more suited to out there because of the terrain or something.

  12. Another weapon from my childhood dream arsenal. The Daewoo promo video is great did anyone get a Missing in action vibe from the music on the video? I kept expecting to see Chuck Norris pop out. The look on the Korean guy’s faces as they shoot was funny. One thing I learned from the video is that it makes a great brush cutter with buckshot. Maybe it’s to unwieldy for bird hunting but it would be great for shooting at junk. I want to start a new shooting sport “competitive broken appliance shooting ” and get a lot of cool firearms off the destructive device list.

  13. Pdb: Yes, one of the effects of a constant recoil cycle is to reduce felt recoil. With open bolt slam-fire, when the bolt closes the moving mass of the bolt group smacks the gun forward as it is firing, negating part of the recoil spike. Energizing the gas system throws the bolt carrier backwards and the rest of the gun forward, further reducing the recoil spike.
    The increased bolt stroke takes more time to travel back, giving the magazine and the whole overall mechanism more time to function, which increases reliability. The bolt is heavier than normal and the recoil spring is stronger, so more stroke the bolt never actually strikes the rear of the receiver. What the shooter feels is the recoil spring pushing the gun against the shoulder as it is compresses and a mirror force as the bolt goes forward.
    The cyclic rate is reduced, sometimes halved, which makes the gun more controllable(softer blows to the shoulder and fewer of them), along with reduced heat output. In Short it brings on a series of cascading advantages.
    Sorry to run on so much, but the subject is hard to sum up in one sentence.

    • No, that was just WW1 propaganda. The British army for one issues a “Combat Shotgun” and has for decades.

      • Thats true, probably some kind of international law, legal ploy devised by Germans that failed, as a sane person cannot see how a shotgun can be more deadly or devastating than bombardment or machine gun fire. For propaganda reasons they tried to villify their enemy in the public eyes, and unfortunately the stupid story stuck for a century

  14. Nice video of the USAS 12. I went to basic training with Donald Thomas’s son. Donald Thomas was acquainted with Max Atchisson. Interesting gun talk with Thomas’s son in the down time at basic training.

  15. As a USAS owner for over two decades now I can offer a bit of experience….
    1) You do NOT want to patrol with a USAS-12 (or even an AA-12). Those things are heavy (13lb empty 15 w/drum), awkward (over 12 inches top to bottom even with the drum and 3 to 6 inches wide depending on column or drum magazine) and ammo limited (stick mags are foot long 2×4’s roughly and the drum is a 3 inch thick 8 inch plate.) Even with a vest I’m limited to two drums and 4 stick magazines (roughly 90rounds on board and you move like a turtle). Crawling in and out of a vehicle? Sure, only a tick harder than doing it with a SAW (N0n-para model) and a couple of assault packs.

    2) Even in Semi, a high rate of fire is quite possible c.300rpm as the ‘constant recoil system’ does truly reduce felt recoil. Then again, that works against you with the limited ammo unless you have a Sherpa.

    3) With the 10-rd magazine you really only get 2 rounds advantage over a standard shotgun and you cannot ‘top it up’ in the middle of a serious social situation like you can a tube fed shotgun.

    The only ‘ding’ in that absolutely stellar review?
    The grip is the AR standard grip, not the grip for the K2

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