Is this a picture from the new Kingsman: The Golden Circle, sequal to Kingsman: The Secret Service? Nah, its just my friend Dickson Ly on a factory tour of Steyr in Austria. What is most intriguing is what he is holding in his hands. It is a rare Steyr ACR. It was developed for the US ARMY’s ACR program. It shoots flechette rounds. The ACR similarities to the AUG but there are some drastic differences. If you notice, the magazine is almost to the very rear of the gun. The action is like a falling block. The chamber would drop down and the round would be inserted into the chamber. Pull the trigger and the chamber is raised by springs and fired. As it cycles, the chamber lowers and the new round pushes the old round forward and out an ejection port.

According to Dickson, the Steyr ACR hasn’t been photographed in about 30 years. There is more interesting stuff to come from his Steyr tour. Stay Tuned.


  • iksnilol

    Man… he looks like the last boss in a videogame.

  • Arie Heath

    Your friend looks like a Bond villain. That is an awesome prototype.

  • Feral Gryphon

    Your friend looks like he would conceal carry two golden Desert Eagles in a John Woo movie.

  • gusto

    if flechettes were anything wouldn’t it have been adopted in the civilian market?

    • Avery

      If you’re building it for the civilian market, why bother using flechettes and use a straight-cased rimfire instead? It’s a falling-block mechanism, they’ve been around since the 1800s.

      • noob

        the ACR features push through ejection that requires rimless case telescoped ammunition.

        No reason against conventional solid projectiles instead of flechettes besides trying to get that elusive 100% improvement in hit probability that was the bar they had to meet to dethrone the M16 as America’s infantry rifle.

    • toms

      They are armor piercing and 100% steel so verboten. I suppose you could make them out of something else.

      • Johannes von’ Strauch

        No you cant, you need absolut insane material strenght, it gets pullet from 0fps to 4920fps in half a meter, everything else get ripped appart, and even copper and brass would be absolutly AP at this velocity.

      • noob

        Is there a law against carbon fiber shaft with a dense lead-tin alloy tip? sort of like a little broadhead arrow? it could be shoved along at 5000fps by some kind of pusher sabot so that the dense tip is forced tighter onto the carbon fiber shaft under acceleration, rather than ripped off the shaft by a puller sabot.

        It would still totally go through body armor but when used in a rifle it might be okay legally.

    • gunsandrockets

      Felony crime to possess in California.

      Of course.

  • The Blinded One

    It looks like he’s about to nonchalantly headshot a bear/flying squirrel hybrid that’s gliding in for the attack.

    • Dougscamo

      Take one more step and the bear gets it…..

  • BrandonAKsALot

    What I wouldn’t give to have one. It’s my favorite vaporware ever.

  • tony

    i remember reading about it in a magazine article back in 1991

  • mechamaster

    Wait.. What ?

    “the chamber is raised by spring when the trigger is pressed ?”
    It’s like “open-bolt” style but in “elevator-style” ? down to upper ?

    I imagine the rest of telescopic-cased ammunition ejection-extraction is like the LSAT, get pushed by new cartridge to the downward ejection port.

    • noob

      the rounds feature a unique annular ring primer midway down the case. As the round rises, the chamber has a hole in the top where the fixed firing pin enters and smashes down into the primer somewhere along the ring of priming compound. this ignites the round and cycles the action. when the chamber returns to its lowest position, the next round is stripped from the ACR’s magazine and the spent casing is pushed out forwards and down, which allows for fully ambidextrous operation.

      it really was ahead of its time

      • roguetechie

        Basically the rising chamber itself is the hammer / striker…

        Which is very beneficial to bullpup design by eliminating linkages and eliminating fcg components in the butt

  • noob

    I’m interested in finding out what modern techniques like metal injection molding, or 3d selective laser sintering could do for flechettes. In the past they were too expensive to make for the benefits you got, but that was before we could get metal parts that were so precise and so hard so cheaply.

    Time for another try?

    • toms

      The tungsten ones were pricey but steel ones were cheap and easy to make as they were essentially nails. I imagine your right on the new technologies though.

      • noob

        hmm. Maybe Lehigh Defense could CnC machine some precision tungsten flechettes using the same production line they use for their controlled fracture CNC brass bullets. G2 research also has high volume CNC machining capability.

        I recall there was a flechette sabot for a very long SPIW flechette that was compatible with a 5.56 case? that could be 3d printed or injection molded to get ammo that would work in an AR15 maybe

        • tts

          CnC’ing tungsten flechettes sounds too expensive to me.

          I think it’d almost have to be steel to keep costs in line. The big problem with flechettes wasn’t with composition from what I recall anyways. It was with the sabots needed to make them work.

          • noob

            Has a good aeronautical engineer studied non-cup type sabots any smaller than for 120mm cannon with modern fluid dynamics?

            Maybe there was something we can see now that was missed back then. It would be crazy if you could injection mold a plastic sabot with a pocket here or a groove there which would enable perfect separation and high accuracy.

            You could create a squad auto or dmr rifle with a minimum precision range of say 10m for infantry combat. Any closer than that and the sabot petals would act like shotgun wadding, causing unintended wounds on impact, so you could transition to a sidearm or PDW for room clearance.

            I also heard that flechettes have a much narrower shock cone so people don’t hear the sonic crack as loudly as normal bullets – which makes the suppression effect more dependent on getting the rounds close to the listener.

            The ancient Romans actually worked on this problem – drilling holes into the stones they cast from their slings. These stones made a whistling sound when they flew, and in large numbers was terrifying.

            An efficient whistling flechette which was loud and low drag would announce on the battlefield that something new and deadly has arrived.

            When you want discretion, you’d switch magazines to the non-whistling flechettes and appear to be coming with supersonic projectiles from nowhere.

          • gunsandrockets

            Interesting idea, but I don’t think loud and low-drag go together!

          • Johannes von’ Strauch

            Correct. Lound and low drag dont work together.

          • noob

            I would allocate some tiny percentage of your energy to sound production downrange and then design the whistle to convert as much of that energy to sound as possible.

            Remember we are only wanting it to be as loud as a coach’s whistle or so (and a coach’s whistle is powered by human breath in the 10s of joules), and we can make a terrifying racket by increasing the number of projectiles.

            We aren’t fixing to break window panes with the sound output or anything.

          • roguetechie

            Realistically, the crack sound only suppresses if the miss is forward of your ears and within about a 1 meter circle.

            Don’t worry about making it loud.. Make it fly straight and fast and you’ll miss by less if you miss giving you the suppression anyway…

            Plus the visual cues from tiny 5000fps missiles smacking stuff around you will be plenty effective

          • tts

            Unfortunately I have no clue if the materials and modeling sciences have advanced enough to make the idea work. I haven’t heard of any other major attempts to make the idea work since the ACR got canned.

            I’d love to see it work though. A near 5000fps projectile would mean you could virtually ignore ballistics and wind out to a decent distance. Probably be about as close as you could get to shooting a laser using actual projectiles of some sort.

          • roguetechie

            The small caliber sabot issue has been solved and with modern manufacturing technology would be cheap and simple enough to make in high volume at the required precision…

            Look up the cbj-ms pdw from cbj tech.ab

            They’re actually working to bring the sabot technology they developed to 5.56 / 7.62 NATO sized cartridges.

            I’d dearly love to have something like a 5.56 case necked out to accept 8mm sabot and a VLD 5.56 OR 5.45 bullet in the 45-62 grain range at 3500 fps MV that is still over 1800 fps at 750 meters…

            Best part is you could optimize the bullet for velocity retention and terminal ballistics alone, letting the sabot do the obturating and riding the rifling…

            The kind of ridiculously short time of flight to 300 meters where you don’t even have to lead a man sized target…

          • RandomInsider

            Haha you waist so much energy with a frigging 8mm sabot. Expecally at that velocity. But there is development in a similar direction, just a more modern and far better approach.

          • noob

            now that is interesting – and very much do-able. if cutting the chamber is expensive, what about having a 7.62mm sabot with a vld projectile in it, and have it work out of a .300 blackout chamber?

          • roguetechie

            … Indeed

            I’d really love to see a roided up FABRL setup running a sabot and in a 14.5 inch bbl just to see whether we could make some super light and freaky awesome 3550 fps MV carbines with a DU penetrator AP version!!

            Stupid short time of flight to 500 meters !

            Riflemen who think bullet drop is when the ammo can falls off the MATV bumper

    • RandomInsider

      There are a ton of problems with flechette, but there is one company that basicly perfected them in smallarms, they under testing right now.

      • mig1nc

        More info? Sounds interesting.

        • RandomInsider

          Its interesting yes. But there isnt any info out. I just know him.

    • roguetechie

      I had a wild thought this morning because of your comment…

      I had this vision of basically a trimmed 30 carbine shell with a slight taper and a sabot in the end… This sabot though had a “donut” of shear thickening fluid embedded at the very nose with the projectile coming to a point centered in the donut.

      The pistol that fires this bullet has a pull then push feed like boberg xr9 but a barrel that extends forward the same amount as a g17 bbl (so total bbl length=g17+1 inch or a bit more)

      However the barrel went from around 8mm at the throat to about 5.56-6 at muzzle… So taper bore.

      The idea being that the metal base cup of sabot combined with STF donut would give you an 1800-2300fps long 5mm dart when the sabot separates at the muzzle.

      Ideally this gives you a long very aerodynamic 5mm flechette as long or slightly longer than the COAL of your loaded round. By using STF and polygonal or other similar rifling pattern plus polymer barrel bearing surface of projectile you should get pretty decent barrel life and a very quick but light projectile that doesn’t shed velocity like most handgun rounds…

      In theory if it all worked out you’d have a handheld AP death ray that also does horrific damage to unarmored personnel too!

      It’d be very tricky to get just right and you’d want a very interesting chamber profile probably out of something super alloy, but you’d essentially have a pistol that sidesteps most of the things that make current pistols suck while still generating less recoil than 9×19 115 grain NATO ball ammo.

      • noob

        so it is like a squeezebore, but using shear thickening fluid instead of plain old lead to work safely at lower handgun pressures.

        Sounds interesting. Is there a reason to use the push pull loading that is related to the projectile, or is it just for low overall length for the handgun?

    • haxfar

      The problem with flechettes, is that they create a really small permanent cavity and a practically no temporary cavity. Those to things are what kills, since that is what causes the blood pressure to drop.

      • Quest

        Flechettes fishhook instantly when hitting flesh and rip trough sideways, and no they create a temporary cavity.

      • noob

        Make it strong but ductile so that it could bend into a J shaped hook on impact? if the flechette did that you’d have it cut out a hole with a perimeter the length of the flechette.

  • Johannes von’ Strauch

    The most sexy gun EVER! 30frigging years ago.

  • noob

    M1001 High Velocity Canister in the bottom barrel and you’d have the ultimate combination gun for hunting… um… Light aircraft maybe?

    Well, it *looks* like it has a sporting purpose. I want one.

  • Sianmink

    Look at how short that action is. There’s almost nothing behind the magazine. <3

  • Bland Samurai

    I believe the Smithsonian has all four. They had just received them when I visited ~ 8 years ago.