A product of the 1960s, the Mark I Gyrojet uses a 13mm 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. Fixed blade front and fixed notch rear sights, front-mounted hammer, "EXPERIMENTAL/MARK I" marked on the left side, and a pair of smooth grips. With a hardwood MBA display case, ten dummy rounds of Gyrojet ammunition, collection of MBA pamphlets, correspondence from MBA to original owner, two MBA certificates, operating instructions, and a signed copy of Mel Carpenter's "An Introduction to MBA Gyrojets and Other Ordnance". Due to a factory error, Serial number A0003 was printed on the handgun's certificate of authenticity. This serial number was listed as a Gyrojet carbine shipped to the same person as this handgun in the correspondence.

Excellent, retaining 99% plus original blue finish with limited minor handling marks. Mechanically excellent. Case is excellent with minimal minor handling marks, a slight patina to the lid plate, and some typical high edge wear to the lining.