Forgotten Weapons: Gyrojet Rocket Carbine At RIA

Sometimes, it seems like few gun designers are willing to throw caution to the wind and try something truly new, and that even fewer financiers are willing to help those few designers achieve their vision. The Gyrojet family of weapons is perhaps an excellent example of why. Innovative, clever, and truly unique, the Gyrojets were a total flop in the marketplace, not the least of which because their practicality as weapons was decidedly limited. Ian of Forgotten Weapons takes a look at one of the rarer Gyrojets, the Mark 1 Model B carbine in a video embedded below:

Both the Gyrojet pistol and carbine used an innovative mechanism with one moving part: A hammer. This piece, actuated by the trigger, slams to the rear on firing, hitting the nose of the rocket, which then pushes on the hammer, re-cocking it, and then leaving the muzzle. The next round is pushed into the firing position by simple spring pressure. No traditional chamber is needed because the rounds do not produce appreciable pressure inside the weapon.

The downside of this is that the projectiles leave the muzzle at very low velocity, which is where velocity is most critical for producing good wind resistance and trajectory. And, of course, the rounds were less effective the closer the shooter was to the target. Further, the ammunition was expensive, as it needed to be precisely manufactured to work and to stabilize.

All negativity about the concept aside, the weapons represent a rare look into a paradigm that is totally alien and unrecognizable. Writers of fantasy and science fiction should take a good, hard look at the Gyrojet as a model for how the fantastic can be realized, and how to give a far-out concept a downright traditional appearance (the Gyrojets were manufactured in the 1960s, but the Mark 1, Model B carbines in particular look like they belong to the 1890s at the latest).

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


  • Matrix3692

    I remember reading from a translated Japanese science fiction novel, and in it, there was a prototype Individual anti-tank weapon that utilize the same principle as the Gyrojet, only that it launches a hyper velocity kinetic round……

    • So, every Japanese science fiction piece evere?

      • Matrix3692

        nah, just a piece only……

  • PeterK

    I want one! That looks rad.

    Is this now how recoil-less rifles work? Except _with_ recoil? Interesting.

    I also really like how you pointed out the anachronistic aesthetic of the thing.

    • No, recoilless rifles work with a standard round of ammunition that in one way or another vents most of its gas rearward to counter-act the momentum of the round moving forward.

  • G0rdon_Fr33man

    Pancor Jackhammer! Will it happen!?

  • j_case

    i wonder if to fix the low muzzle velocity problem, it would have been possible to add a powder charge to the projectile as well, kind of like a hybrid gyro/classical projectile.

    • ostiariusalpha

      That could work. Maybe some kind of sabot to get it started, then let the rocket increase (or even just maintain) the velocity from the muzzle. If it could be perfected, think about the range you could attain with a flatter trajectory. I just don’t see the expense going down that much though.

    • Tom

      It would work as far as making the projectile more efficient at close range but then you would need to build the gun to be stronger and hence heavier mitigating the advantage of light weight construction you began with.

      The Gyrojet is an interesting andd novel concept but without some major advances in material science I can not see that you will ever be able to make one that is more efficient than a conventional rifle. Especialy if the later is loaded with something like a 10x24mm explosive tip caseless light armor-piercing round.

      • Phil Hsueh

        What about a compressed air/CO2 charge to launch the round out, although I suspect that it still wouldn’t generate much velocity.

        • j_case

          i think the extreme end on a paintball gun firing paintballs is around 650 fps. im sure a purpose built setup could hit significantly higher speeds

        • Tom

          added weight from the CO2 tank plus the complexity of timing the release valve. Nether are insurmountable, in fact I rather suspect the latter is fairly easily done but you still loose the lightness and simple construction which were amongst the main selling points.

        • DClan

          I was just thinking that, use compressed CO2 to get initial velocity up into the 450-500 FPS range, enabling an earlier activation of the onboard fuel.

  • HenryV

    Come on Ruger you know it will be a winner………….

  • Iggy

    Alternatively sci-fi writers can take the 40k approach, and take the gyrojet, scale it up to .75 and place the round in a cartridge and make it a machine gun:

  • Giolli Joker

    He even went full flat on the ground… GREAT!

  • Brocus

    one moving part you say, so manufacturing an accurate replica – as a wallhanger given the lack of ammunition – would be quite possible, or is there still someone holding any kind of rights to the design

  • David Hardy

    Brought back pleasant memories of working at Tower Gun Works, Teddington, Middlesex, England. Spent a couple of years with them in the late ’60s. Had a job to make ‘dummy’ GyroJet rounds for a local film company. Had to make them to fit the pistol used & detailed down to the rear ‘jet’ cap. Forget the name of the movie but I still have one of prop rounds.

    • Mazryonh

      Do you have any images of that prop round you can link to?

  • The gasp makes it.