Was Clyde Farrell’s Rocket Machine Gun a Hoax?

The July 1934 issue of Modern Mechanix featured Mr. Clyde Farrell’s Rocket Machine Gun invention, more than 30 years before the first commercially available rocket gun, the GyroJet pistol, went to market. From Modern Mechanix

A MACHINE gun hardly heavier than an air rifle, yet capable of firing 700 shots a minute with almost no recoil and no possibility of overheating, was recently ‘announced by its inventor, Clyde Farrell of San Francisco.

Special bullets receive only an initial impetus from the firing pin, and generate their own energy in flight, just as do rockets. All remaining energy is released when contact is made with the target.

Bullets joined together with aluminum wire feed from an endless chain in the regulation machine gun manner.

The complete gun weighs only three and a half pounds. Models have already been tested, and are now at Washington to meet final patent requirements.

It was light, had a high rate of fire, no recoil and belt fed. The weapon seemed to good to be true, so I did some investigating. I could find no rocket machine gun patented in the 1930. There are some patents related to rocket machine guns in the late 1940s, but they are for large caliber conventional military rockets designed for aircraft. In fact, I was unable to locate any USTPO patents that were filed by, or listed the inventor as, “Clyde Farrell”.

The claims of being belt fed seem very unlikely. A belt fed weapon needs a power source capable of pulling in rounds and ejecting the empty case and belt links. In magazine weapons this energy is provided by the magazine spring. Belt fed weapons are either powered by gas, recoil or by an external electrical power source. Unlike conventional ammunition, which burns all its propellent inside the barrel, a rocket burns most of its propellent outside the barrel while in flight, thereby generating very little energy inside the gun. The Gyrojet rockets left the gun at just 20 ft/sec! It would not be able to generate enough momentum inside the gun to pull in rounds as well as cocking the hammer. The Grypojet was so slow you can see the rocket bullet leave its barrel in the below video.

Another detail from the article that seems unlikely is the claim that the rocket was ignited by an impulse from the firing pin. If the firing pin was behind the rocket, the hammer would also need to be behind it. If this was the case, how would the rocket cock the hammer? The Gyrojet had a fixed firing pin. Its hammer was in front of the rocket and pushed the rocket into the firing pin. After the rocket was ignited, it pushed the hammer forward as it left the barrel, recocking the gun.

So in summery: the design appears to be impossible. If it really could do what it claimed, it would have definitely been patented.

Gyrojet being fired.

[ Many thanks to Sven (Defense and Freedom) for emailing me the the info. ]

Steve Johnson

Founder and Dictator-In-Chief of TFB. A passionate gun owner, a shooting enthusiast and totally tacti-uncool. Favorite first date location: any gun range. Steve can be contacted here.


  • SpudGun

    Everyone knows that Clyde Farrell was a Time Fugitive from the future and was mysteriously taken out by Continuity Agents from the 4th Dimension before he could develop his rocket gun to stop Hitler. I mean, duh.

    Perhaps the claims of the recoil were over exaggerated, it might have had the same recoil as a .22LR and compared to a .30-06 round, it would have felt like an air rifle, comparitively speaking and thus the bolt cycling.

    More likely, he was just a well meaning inventor and this was just some fanciful newspaper spin. How many times have I seen the same story about the dude who built the flying car over the last few years?

    Rumors that MagPul are making this soon are also unfounded.

  • K!P

    Just some random toughts:

    if you would make some sort of rocket/normal round hybrid it might be possible: use a lighter recoil round to fire the rocket down the barrel, use the rocket to speed it up faster in while flight, but use the reduced recoil for better control as well as powering the reloading mechanics.

    Still has a mayor downside: expensive rounds.

    Maybe adding control surfaces (vectored trust?)to the rocket round to increase accuracy/tracking rounds. Guide it on target with a steering wire/wireless control, assuming you can produce something small enough to fit a reasonable sized round, yet tough enough to survive the initial acceleration. or go with electric feeding, and just rocket power (to reduce the initial blast off).

    Just a few more years of imaginary development and BOOM instant sniper accuracy, without training (other than keeping the sight on target).

  • zincorium

    I’ve never understood why a hybrid between a gyrojet cartridge and a conventional cartridge was never developed- just enough powder to send it through rifling and out of the barrel at lethal speeds.

    Yes, you’d lose some benefits of the gyrojet system, but it would still have lower recoil and low chamber pressures.

  • Harald Hansen

    Interesting. Some pen-and-paper role-playing game from years past (I forgot which) predicted Gyrojet-type weapons as the next big thing after regular gunpowder weapons. It glossed over the technical details, though…

    BTW, I would advice the narrator in the Gyrojet clip to brush up on the definitions of either “literally” or “light year”. 🙂

  • Ben

    What if the rocket machine gun cartridge uses a primary charge like an rpg7 and then continues on a rocket. It would be expensive but it could make the weapon cycle with far less recoil.

  • The gyrojet. I really wish someone would create a modern clone of the weapon, complete with functional amunition. However, for a handgun whose projectile takes 25 yards before reaching it’s maximum velocity, it would almost certainly be wholly ineffective as a pistol. Even if the rockets could be stabilized to the point of being accurate, and something along the lines of a red-dot sight installed on the top (No slide movement, nor recoil whatsoever for that matter.) the weapon still faces the crippling issue of not being able to perform adequately at the crucial sub-10 meter envelope, which is where most other handguns excel.

    I have always wondered what the point of having a gyrojet rifle was? If the projectiles are self propelled, then the extra length of barrel would impart virtually no benefit in muzzle velocity whatsoever. A gyrojet rocket fired from a 4 inch barrel should have a virtually identical velocity to the same rocket fired from a 24 inch barrel. Could someone confirm this?

  • “LITERALLY light years ahead of it’s time…” I don’t think that word means what he thinks it means.

  • I’ve actually seen one of the gyrojet handguns, but I’ve never heard of the machine gun. If you get a line of how the belt fed version worked (if it ever worked) I hope you will share with us.

  • armed_partisan

    Gerald, I think the idea behind the rifle is that it gave the round enough time to build enough velocity to penetrate something that was placed directly in front of the muzzle. Small Arms Review had an article a few years back about “The Gyrojet in Vietnam”, which is the first place I recall reading about these things, and there were a few stories of guys who used them in combat, to very, very poor effect. I believe there’s one story about a VC that gets shot with a Gyrojet pistol, and it not only doesn’t kill him, it doesn’t even penetrate him, and he’s distracted by the whirling, buzzing round that zips around on the ground after hitting him, probably thinking it’s a mini-grenade, and he runs away.

    I’m actually working on a patent for a modern version of this idea. I think mine will have other applications, but even if it doesn’t work, I’m sure it will be fun to play with.

  • Clodboy

    “Interesting. Some pen-and-paper role-playing game from years past (I forgot which) predicted Gyrojet-type weapons as the next big thing after regular gunpowder weapons. It glossed over the technical details, though…”

    The Space Marines in the Warhammer40K universe wield so-called “Bolters” as their standard assault weapon, which are essentially Gyrojets firing .75 caliber armour-piercing explosive rounds.
    (Nifty fan-made vid detailing the technology: http://www.youtube.com/watch?v=tnHyEhS1lSM )

  • A firearm inventor who over-hypes his invention, and credulous reporters who bite hook, line, and sinker. When has that ever happened in recorded history? The next step is to claim that those evil folks at the US Army Ordnance Department suppressed it.

  • me

    Step 1: dump buckshot out of 12 gauge shell
    step 2: put gyro-jet cartridge in shell
    Step 3: Rocket boosted Slug FTW.

  • Raoul O’Shaughnessy

    Hmmm….if nothing else this little piece shows that firearms ‘vaporware’ isn’t anything new.

  • Steven

    A rocket gun does not need a cyclic mechanical action. Made a recoilless rocket gun as a kid, it was nothing more than a tube with a handle to shoot bottle rockets. Tried to make it “belt” feed by chaining the fuses together so the one leaving would light and pull the next one into the tube. Here is a more developed version with a rate of fire of about four rounds a second. http://www.youtube.com/watch?v=exGopcvFz3E

  • Cam

    One thing they didn’t mention in the clip is exactly why the rounds had a tendency to veer off target. It wasn’t the lack of rifling or the short barrel, it was due to manufacturing inconsistencies with the rounds. Some had vents that wouldn’t fire off the rocket fuel at the same time, or at all, or with too much force, causing the round to spin wildly and thus miss.

  • charles222

    The Future Warrior program had a 15mm rocket-firing pistol as the primary weapon for awhile, iirc.