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. Fixed blade front and notch rear sights, "EXPERIMENTAL/MARK I" over the serial marked receiver, a magazine cover mounted on the left side, front-mounted hammer, and a pair of smooth grips. With a hardwood MBA display case, Robert Hutchings Goddard medallion, and ten dummy rounds of Gyrojet ammunition. This pistol along with a Gyrojet carbine with the same serial number, lot 588, were both originally shipped to a Dr. Robert D. Taylor. An included letter from MBA details the shipment of this pistol as well as Dr. Taylor's friendship with the heads of MBA. Also included is a certificate of authenticity issued to Dr. Taylor and stating this "is an experimental gun used in the research and development of the high-performance 13mm Gyrojet Rocket handgun" and an extensive collection of documents pertaining to the development of Gyrojet firearms including advertisements and correspondence relating to the pursuit of government contracts.

Excellent, retains 99% original black finish with a grey patina visible in the markings on the left of the frame, and minimal handling marks. The fire controls have turned to a brass/copper patina. The grips are excellent with only the slightest handling marks. Mechanically excellent. The case exterior is very fine with some scattered minor handling/storage marks and there is a moderate rip in the lining of the lid with the interior plaque detached but included.