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Historical Handguns

Rocket-Powered Pistol: MBA Gyrojet Model B

by S.P. Fjestad   |  July 26th, 2013 6

MBA-Gyrojet-Model-B_001OK fellow rocket scientists, you’re going to like this from Blue Book of Gun Values.

When John Glenn, Neil Armstrong, Buzz Aldrin, James Lovell, Alan Shepard and the rest of the astronauts were launching off on top of their massive Saturn 5 rockets from Pad 39A of NASA’s complex in Cape Canaveral, Fla., during the 1960s, Robert Mainhardt and Dr. Arthur Biehl—hence MB Associates or MBA—were getting their rockets off horizontally at a gun range. This is certainly one of the more twisted stories I’ve ever covered in the firearms industry.

After Robert Mainhardt figured out that his new gun—actually, a launch tube would be more accurate—which fired rocket-powered projectiles would not be a military success, he made a trip to Colt Firearms for a possible company sale and was amazed at all the fancy commemoratives Colt was selling as fast as they could make them.

He decided to take a similar approach, and this Mark I with display case released in 1965 contained eight inert rocket cartridges and a bronze medallion of Dr. Goddard, “the father of modern rocketry.”


This time lapse image shows the rocket blast of the Gyrojet projectile being exhausted from both sides of the rear of the gun. The small separated red discs in front of the muzzle indicate the projectile is just starting to rapidly rotate, which transitions into the spiraling circles starting about a foot from the muzzle, indicating a high spin rate. The angled exhaust nozzles allowed a very high spin rate of five revolutions per foot, or 288,000 rpm at 960 fps. Accuracy proved to be one of they Gyrojet's Achilles heels. One test indicated the best grouping a Gyrojet could achieve with a four-port rocket projectile was a 29-inch pattern at 33 yards.

Each projectile consisted of the case, angled nozzles, primer, residual water proofing, and residual inhibitor. When fired, the grain igniter and primer composition were consumed, so the entire projectile became the bullet down range. There were no empty casings.

Despite the lack of commercial success that had a lot to do with the rocket projectiles selling for $3 each at the time, James Bond used one in You Only Live Twice. So did Steve McQueen in The Hunter. Jay Leno even got involved with one in The Collision Course, which featured a 12mm Gyrojet pistol as the murder weapon.

So what’s this rocket launcher worth? Think of it as an expensive novelty item—in the $2,000-$2,500 range. If you want to shoot it, figure about $35 a round, so each time you load it up (six projectiles), it’s going to cost you approximately $200 when the fireworks are over. You can be guaranteed, however, no gun in your collection will command as much shock and awe as a Gyrojet being fired rapidly on a dark night.

Images courtesy of Rock Island Auctions and An Introduction to MBA Gyrojets by Mel Carpenter. To find more great guns like this one, visit Blue Book’s Gun of the Week!

  • LarryEArnold

    “Novelty” is right. I remember when the GyroJet came out. It turned out to have two little problems.
    First, the pistol (the part you reuse) was cheap but the ammo (the part you expend) was costly. That’s backwards.
    Second, the projectile didn’t really accelerate to effective self-defense velocity until it was past common self-defense range. That’s backwards.
    Unfortunately the two “backwards” didn’t cancel out to a “forwards.”
    The GyroJet is unique, however, in that AFAIK it’s the only small-arms action invented in the 20th century.
    I must be getting old.

    • Mazryonh

      There has been at least one attempt to modernize the gyrojet concept:

      I believe the main problem of those in charge of marketing the weapons was that they tried to market them as close-range weaponry, such as pistols and carbines, when in fact their minimum effective range and increasing effectiveness at range made them better as DMR and Sniper weaponry (their low sound signature when fired would also have helped). Their inherently caseless nature would also have made them excellent weaponry for aircraft (which normally don’t approach within the minimum effective range of gyrojet weaponry), which normally have to allocate weight and space to retain expended casings if they carry guns.

      Imagine if the M79 Grenade Launcher used an upsized Gyrojet concept–that would have enabled it to have better range and likely be lighter, as well as have semiautomatic capability.

  • petru sova

    If I remember correctly there was a GryoJet rifle or at least a prototype made. If the inventory would have figured out how to make it shoot accurately the longer ranges rifles are used at might have gave the gun a marketing chance. Of course we did have a similar weapon in WWII called the Bazooka and in Germany it was called the Panzerfaust.

  • William Lawton

    Would have been nice to see it fired, no video on this, really.

  • oldsoldier952

    After the Gyrojet pistols failed to achieve commercial viability, MB Associates used the same miniature rocket technology in distress ‘miniflares’. They were standard issue for the Canadian Forces and the US Air Force for many years. They were an excellent flare, achieving altitude several times that of the normal 16 mm miniflares (which use a .22 RF blank for propulsion) in other distress kits. They were also capable of penetrating light jungle canopy – something the other flares could not do.
    A few years ago I was responsible for buying ammunition for a particular branch of the service, and remembering the excellent ones from my days with the CF, I tried to locate MB Associates to see if I could buy these flares for issue. Unfortunately they, and their flares, seem to have disappeared.

    • Mazryonh

      Have they gone back to blank-propelled flares then in armies?

      These “Gyroflares” are really just miniaturized versions of good ol’ “Distress Rockets” used on old ships, most famously seen in the Titanic movie–they are set off once the ship starts sinking, but obviously failed to attract enough attention to save everyone.

      You might want to check out the “Deathwind” project that has attempted to modernize the Gyrojet concept:

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