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!

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