Sidewinder SMG Photos

The Sidewinder is a rather unusual submachine gun designer by Sidney McQueen in the mid 1960s. His objective was to create a weapon which could be fired one-handed with the firepower of a submachine gun rather than a pistol. What McQueen came up with was a good example of the “arm pistol” concept, which can also bee seen in the original Bushmaster weapon of this type.


The magazine well of the gun could rotate independently of the grip, allowing the shooter to hold the gun with the magazine canted inside the arm and the buttplate resting against the elbow/bicep area (although some of the guns were made with extendable buttstocks that would be shouldered as well). In total it appears that about 20 Sidewinders were made, in three different models. The SS-1 was chambered in 9mm Parabellum, the SS-2 in .45 ACP, and the SS-3 had interchangeable barrels and a bolt with a 9mm face on one end and a .45 face on the other, allowing it to be flipped around and used with either cartridge.


Development took place from 1966-68, and the idea stagnated for lack of capital and interest at that time. Interest picked back up in the late 1970s, allegedly because of interest from Special Forces units in the military looking for a weapon that could be used while roping out of helicopters. Whatever the reason, the guns were actually manufactured in the late 70s. Full production was anticipated for 1980, but that failed to materialize as no military contract was ever obtained.

Mechanically, the guns are blowback operated from an open bolt, with progressive triggers – a short pull fires in single shot mode and a full press fires in fully automatic. The guns were fed from Sten (9mm) and M3 Grease Gun (.45) magazines. The 9mm SS-1 weighed in at 4.7 (2.1kg) pounds empty, with a 9 inch (221mm) barrel. They were designed with basic open sights, and provisions to mount the high-tech optics of the day, like Armson OEGs and Weaver Qwik-Points (which you will see mounted on this one in the photos above).

Thanks to Joe, we have a series of photos of gun #18 (model SS-1) disassembled:


  1. “His objective was to create a weapon which could be fired one-handed with the firepower of a submachine gun rather than a pistol.”
    If I am not mistaken first sub-machine gun designed around that requirement was Delacre, it was patented in 1936:
    but I don’t know how many (if any) were produced.

    • Motorcycle dispatch rider use perhaps, try and ride one handed while using the gun attached to your arm by a brace to have a pop at Gerry.

  2. In-between the Sidewinder and the Bushmaster was the original “arm gun”,the IMP-221, firing the .221 Remington Fireball round used in the XP-100 bolt-action single-shot “varmint pistol”;–p-e.html

    The Colt SCAMP was similar to the IMP in principle (high-velocity, small-caliber, to achieve the same “stopping power” as a 9 x 19mm), but in overall concept was more a forerunner of modern pistol-style PDWs;

    Oddly enough, the original 9mm Sidewinder manifested itself in the old FASA Shadowrun SF/fantasy roleplaying game, as the Ares Crusader machine pistol;

    So the design has been “around the block” a few times since its conception.



    • Is bull-pup layout really useful in sub-machine gun? SMG with magazine in grip like Uzi have compact size, will have bull-pup SMG significantly better barrel to overall length ratio? Do you know any other bull-pup sub-machine gun developed from scratch for 9×19 or .45 Auto cartridge?

      • None I can think of offhand, I suspect because the overhung bolt/magazine well in pistol grip layout (first introduced in the British MCEM 2 designed by Podsenkowsky at Enfield in 1944-45)is so compact and efficient.

        The “bullpup” can give you a longer barrel, but only at the expense of a longer receiver. And one drawback of the bullpup is that if the magazine is at all close to the rear of the pistol grip, it makes some firing stances difficult or even nearly impossible without a rotating magazine setup, which adds extra parts, weight, and the potential for dirt etc., ingressing the action.

        By comparison, the “Uzi”-type layout can be fired like a pistol if need be, with nothing moving except maybe folding the stock up first. Much less aggravation all around.



    • “The story of the IMP-221 Individual Multi-purpose Weapon (also known as GUU-4/P submachine gun) began in 1968, when US Air Force contracted Colt corporation for development of the air crew survival gun, designated as Individual Multi-purpose Weapon (US AF index GUU-4/P)”

      Aircrew survival gun… Firing one handed, while parachuting? The other steering, perhaps.

        • Easier than with an Fg42 Mk1, although I think that grip angle was actually just about giving the gun a low profile like having folding sights.

          • “To achieve comfortable handling by both right- and left-hand shooters, the pistol grip was allowed to rotate (cant) sideways, and it had three fixed positions – vertically below the barrel, canted by 38 degrees to the left, or canted by same amount to the right. To provide sighting means despite the position of the pistol grip, the IMP-221 Individual Multi-purpose Weapon had three sets of iron sights, at about 10 o’clock, 12 o’clock and 2 o’clock positions.” A less exciting explanation…
            So the idea was to hold it at arms length like a pistol, instead of using a stock.

  3. “Interest picked back up in the late 1970s, allegedly because of interest from Special Forces units in the military looking for a weapon that could be used while roping out of helicopters. ”

    I’ve never rappelled out of a helicopter, but I have rappelled from some good heights as part of a high-angle rescue team. One’s strong hand was used to brake the rope / control the speed of descent. It would have been been challenging to fire anything while going down a rope. I would guess that the best idea would be to hurry up and get down the rope and fight rather than try to shoot on the way down. If there are any military members who rappelled out of helicopters maybe they could weigh in on the subject.

    The design looks handy for one-handed use, however useful that really is, but it looks like it could really only be used one-handed which seems like it could reduce the usefulness of it.

    • I suspect that two-handed firing from the shoulder or with the butt tucked into the crook of the elbow would best be done with the off hand wrapped around the hand on the firing grip, much like a modified Weaver stance with a handgun.

      Handled that way, and with an Aimpoint sight, I’d expect reasonable accuracy out to 100 meters or so, which for the Sidewinder’s purpose was probably good enough.



      • Point taken, but it looks to me to be an invitation for shooting one’s support hand. A few months ago a state trooper near where I live shot his own thumb off when his support hand went out too far and he fired too fast as he was being fired upon. Getting the support hand out too far can be an issue.

        Given some stress, what are the odds that one goes into SMG mode and grabs for the non-existent hand guard and destroys their support hand with this gun? Even if it only happened one out of a thousand chances that would be a lot of soldiers with mutilated hands. I think a more pistol-like gun (like a MAC or a mini-Uzi) would not have that issue as one would go into handgun mode with something that looks be feels like a handgun. As a trainer would one train people to use a two-hand hold, keep the support hand well away, or try to talk the unit out of using them at all?

      • Weapon of choice scenario:

        Okay, no monsters around (and thank goodness for that). Let’s do a training exercise. There is a selection of pistol-caliber weapons on the table and a varied set of “combat conditions” to run them through. One has to hit moving targets (metal silhouettes on carts and hinges) in urban conditions and then pick one of the following environments (or more if you prefer):

        1. No-man’s land
        2. Desert
        3. Jungle
        4. Tundra
        5. On board a ship (no pirates or U-boats anywhere nearby, but I could be wrong…)

        Under no circumstances is the participant comfortably sitting at a bench with any selected gun on a padded rest. The weapons on the table are as follows, but you may bring your own.

        1. Sidewinder
        2. Uzi
        3. Beretta M12
        4. American 180
        5. KP M/44 with drum
        6. Mauser M712
        7. Type 100 SMG with bayonet
        8. Steyr-Hahn Repetierpistole M.12 or Doppelpistole M.12
        9. Winchester Model 1892 in .44-40 Winchester
        10. Screw this! Get your favorite handgun, carbine, or SMG!!!

        This activity is totally voluntary. You are not required to participate if you do not wish to do so. Please keep any and all criticism of this post humane and free of foul language.

        Thank you,


        • Jungle, with a sidewinder… I want to see if I can do any better stood behind a tree that stood behind a wall in the urban environment, I just can’t see the sights!

        • Tundra, Winchester ’92 .44-40. Among other things, it is more accurate, longer-ranged, and hits harder than anything else mentioned. Also reasonably easy to “top off” and fire while wearing gloves, and has no separate magazine to get lost. Neither does the Steyr M12, but chargers are a fumblesome thing at best in most of the conditions mentioned.

          BTW, if I had my preferences, it would still be a Winchester lever-action, except it would be the ’94 in .30-30 WCF. Not quite the oomph of a .308, but more than enough to get the job done.



          • “lever-action”
            What you think about pump-action rifle – namely Remington Model 141 – for that job. Is it superior, equal or inferior?

          • D;

            Pump rifles are just fine, if you’re used to them. A Remington 760 with a 20-round magazine in .308 is a formidable fighting rifle in the hands of someone accustomed to it.

            I was brought up with lever guns. They’re what I’m used to. I’m actually a bit slower on repeat shots with a pump than I am with the lever-action.

            To a great extent, speed and accuracy with any rifle comes down to your familiarity with it.

            It’s all what you’re comfortable with, really.

            Merry Christmas.



        • “10. Screw this! Get your favorite handgun, carbine, or SMG!!!”
          If you except extreme adverse environment condition get Australian OWEN sub-machine gun, it looks somewhat peculiar, but it works when you need it.

          If you want more range then get Hungarian Danuvia 39.M sub-machine gun (it fires 9×25 cartridge) or its development Cristóbal Carbine (firing .30 Carbine)

    • What about if you were in a boat with a outboard motor, firing at parachuting Impis of Zulus with on hand while steering the boat with the other.

      • You’d be screwed. Driving and shooting at the same time is a bad idea. There is a good reason why the “one-man tank” idea didn’t work. Have a friend steer the boat, since your eyes wouldn’t be able to concentrate on avoiding the exploding barrels in the water while shooting at enemies in the sky!

        • “There is a good reason why the “one-man tank” idea didn’t work.”
          Yep, but notice that inter-war American M2 Light Tank has machine guns mounted in sponsons (aligned with hull) fired by driver, so in DIRE need it can be used only with one crew member.

          • The one or two-man turret in most tanks up to T-34/76 ’43 wasn’t a good idea, either. The tank commander needs to concentrate on command, not loading or laying the gun.

            BTW, this is why the Bundesheer habitually puts the A/A 7.62 MG on the loader’s hatch on the Leopard 1 and 2 series. They feel that the commander has more important things to do than operate a medium MG.

            The U.S. Army and Marine Corps, and the Israeli Defense force, put the 7.62 on the loader’s hatch but give the commander a 12.7mm “fifty”. On the assumption that if it’s important enough for the commander to drop whatever he’s doing and shoot at it, it probably needs to be stopped as hard as possible short of a main gun round. Like clearing a sniper from the top floor of a building without bringing down the whole structure, for instance.

            Ad of course, the 7.62 and 12.7 on the M1 series have been remote control right from the start, even before TUSK. In MOBUA, you generally don’t want to stick your head out of the hatch if you can avoid it. The British learned that lesson in Aden, hence the remote-controlled GPMG on the Chieftain.

            The U.S. forces had the cupola on the M48A2 and later, but thought it was a handicap in Vietnam. They soon learned that you don’t bolt the fifty on top of the cupola and sit in the open hatch to use it in Sniper Heaven.

            The French learned it- finally- in Algeria. But they didn’t have a remote-control on the commander’s gun until the LeClerc.

            From all I can tell, the Russians and Red Chinese still haven’t figured it out.



          • “the Russians (…) haven’t figured it out”
            Last Russian tank – Object 148 (also known as T-14), has 7.62mm remote controlled machine gun – see cut-away in this article:
            It can’t has manned machine gun on top of turret, because turret itself is man-less.
            Object 148 is subset of bigger project – project ARMATA (very old Russian word meaning cannon) – so far known vehicles of this project:
            Object 148 (T-14) – 5th generation (Russian-style) or 3rd generation (West-style) tank, armed with 125mm gun (can be up-gunned to 152mm gun)
            Object 149 (T-15) – infantry fighting vehicle, main gun: 30mm automatic gun 2A42
            2S35 (“Koalitsiya-SV”) – self-propelled 152mm gun, probably will replace Msta self-propelled gun
            Object 152 (T-16) – ARV
            BMO-2 – flamethrower fighting vehicle
            TOS BM-2 – heavy flamethrower system (probably thermobaric rocket launcher, like TOS-1 Buratino)
            TZM-2 – ammo carrier for above mentioned TOS
            USM-A1 – mining system
            MIM-A – engineering vehicle
            UMZ-A – mine layer
            MT-A – bridge tank
            PTS-A – swimming transpoter

      • And like you say, surely the best idea is to get onto the ground quick and shoot back not dangle around trying to have a mid air firefight with one hand.

        • If someone shot at me while absailing from a helicopter I’d have severely friction burned gloves and a sore arse from a very speedy descent indeed.

  4. With a camera mounted instead of the “scope thing” that transmits the imaging to a smartphone, you could shoot round corners via a laser beam aiming module thing viewed through the phone. This SMG’s concept is a bit like the spinny around butt plate on that shotgun, from around the same era. Only the magazine stays in the downwards position with you holding the pistol grip which is rotated sideways like a Sten gun mag, while the butt plate is in the normal position but resting against your bicep, as oppose the butt plate on the shotgun being thus while the entire gun is rotated so the pistol grip is sideways i.e. Sten mag, like.

    • If I understand the article correctly: “The magazine well of the gun could rotate independently of the grip, allowing the shooter to hold the gun with the magazine canted inside the arm and the buttplate resting against the elbow/bicep area” You could stand behind the corner, holding your phone in your left hand looking at the screen with just your folded right arm/hand available to be shot at via it holding the gun- The butt plate against the right bicep facilities this hold as a practical position, because you can balance it thus etc.

      • You could attach the screen to the gun, on the receiver side of the photo which shows it’s muzzle pointing left.
        Aftermarket pistol stock idea perhaps, er… Scope mount, like off race guns “goes from the accessory rail over the slide, type thing” modified so an extension rail, extends over the top of the slide until it reaches the maximum point of it’s rearward travel then it has swiveling attachment thing for a detachable stock that then extends back from it, the butt plate of which would rest against your bicep. The stock has a clip for a smart phone to be attached in the position as alluded to above, then a combined laser/camera module attaches to the rail extension i.e. Above the slide.

  5. The design reminds me of a story about an inventor who had just came up with a clever submachine gun design. He went to an arms factory and presented his design. The man across the desk then pointed to the corner and said “see that safe, it is full of clever submachine gun designs.” I suppose the point being that where creativity is needed with submachine guns is not so much in their design but in explaining why one someone should buy a submachine gun in the first place.

    • It would allow you to hold it, shouldered “so a more effective hold for a smg” while freeing up a hand… The answer to why, that is a good idea may be found in the 10b shotgun manual which I never read. Suppose if you were a lone Police officer, having to open door handles in blocks of flats or something that might be handy- Shotgun/Smg being deemed as more effective than a pistol.

      • I think it is in someway related to the 10b, in that the sidewinder achieves the same thing as the spinny around stock but in a manner which is more practical for a weapon with a long magazine, as oppose a tube.

        • And both therefore are possibly developments of the
          IMP-221, but utilizing butt plates as oppose the design originally coming about to facilitate left/right handed “modularity” a current buzzword, when firing a bullpup like a pistol i.e. With an outstretched arm, so without using a butt plate.

  6. I have a couple of the bushmaster arm pistols. Neither of mine were reliable at all. It was a rare thing to get either to run through a whole mag without multiple stoppages. I have my doubts as to their usefulness. An outside the box concept that was not executed well. Sure is impressive firing 5.56 out of that short barrel at night though.

  7. Since there were so few of these made, how much would one of these guns be worth to a collector today? How would you go about getting an official appraisal for it if you had one?

  8. The Sidewinder turned up in some of the action adventure novels of the day. It’s a bit surprising it didn’t end up in the action movies of the day, or at least a prop version of one.

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