A product of the 1960s, the Mark I Gyrojet uses a miniature solid fuel rocket in place of a standard cartridge. As the rocket does not need a solid chamber or extractor equipment, the entire pistol can be greatly simplified and made from lightweight materials. Elevation adjustable blade front and fixed notch rear sights, a sliding magazine cover, front-mounted hammer, cast model, caliber and serial number markings on the left side, and a pair of smooth grips. With a hardwood MBA display case, Robert Hutchings Goddard plaque, and ten spent rounds of Gyrojet ammunition.

Fine. The pistol has been polished mostly bright overall with some small traces of original black finish in the protected areas, handling marks, and some small surface scratches. Grips are very fine. Mechanically excellent. Case is good with dings and scratches on the exterior, and reglued lining.