Make: MB Associates (MBA)

Model: Mark I Model B Survival

Serial Number: B54398S

Year of Manufacture: 1965-1968

Caliber: 13mm Gyrojet, a 13mm spin stabilized rocket cartridge composed of four part solid rocket fuel. (ATF Exempt, non-Destructive Device)

Action Type: Semi-Automatic with Fixed Magazine

Barrel Length: There is a 3 1/2" telescoping tube inside the frame, when extended out it is approximately 7" from the muzzle to the firing pin.

Sights / Optics: The rear sight is a square notch integral to the loading port cover. There is no front sight.

Stock Configuration & Condition: The grips are integral to the frame, appearing as a checkered panel on each side. There are a few nicks and minor scuffs in the well defined checkering. Overall, the grips are in Very Good-plus condition.

Type of Finish: Jungle Green

Finish Originality: Original

Bore Condition: The barrel tube shows little sign of use. There is a small nick on the muzzle-end. In this writer's opinion, the bore rates about 9/10.

Overall Condition: This pistol retains about 85% of its metal finish. The finish is thinning at some edges. There are scattered light nicks, scuffs and scratches. There is some scattered finish wear and discoloration, giving the frame a slightly mottled appearance. The screw heads are lightly tool marked with strong slots. The markings are clear. Overall, this pistol is in Very Good condition.

Mechanics: The action functions correctly. We have not fired this pistol. As with all used firearms, a thorough cleaning may be necessary to meet your maintenance standards.

Box, Paperwork & Accessories: None.

Our Assessment: Who doesn't want a hand-held rocket launcher? MB Associates thought the answer would be "everyone!". Robert Mainhardt and Arthur Biehl met while working together at Aerojet-General Nucleonics, working on their AGN-201 nuclear reactor. While MBA was profitable in their manufacture of chaff and flare devices for aircraft, the Gyrojets would have to be considered something of a passion-project.

The cartridge design actually hearkens back to one of the earliest self-contained cartridges, the rocket-ball. With all of the propellant contained in the cartridge, a fixed firing pin is ignited when the hammer strikes the front of the cartridge. Once ignited, the burning propellant comes out of angled ports at the rear of the cartridge, spinning the entire assembly to stabilize it as it accelerates down the bore. Unlike traditional cartridge firearms, the projectile continues to accelerate for up to 20 yards after leaving the bore, reaching its highest velocity not at the muzzle, but when the propellant is exhausted. Quieter than a traditional cartridge, the firearm could be made extremely light as it did not have to contain much pressure, and it would work under water (in theory).

This example is a Mark I Model B, using the 13mm cartridge with an improved slide-style loading port cover. It is a Survival variant, rather than a fixed tube for a barrel, the tube telescopes to allow the pistol to be more compact for storage and transport. While other observed examples had a collar on the front with a front sight blade, this example has no front sight. While the Mark I Model B was the most produced of the Gyrojet models, it also saw the greatest number of variants and the Survival model had only a few dozen made. Ironically, the Survival model would inspire the most successful of the Gyrojet products. It was found that Gyrojet flares were very capable of penetrating jungle canopy, and so were ideal for a survival flare in that environment. A much simplified mechanism, more like a pen-gun, would be adopted for pilot survival kits and were still in service as of 2012.

With about 1,900 Gyrojets produced in all of their pistol and carbine configurations, any example is a good find. This rare Survival model will make it a great addition to a collection that already has a few Gyrojets. Please see our photos and good luck!