Designed as a carbine version of the MBA Mark I Gyrojet Pistol and utilizing the same 13 mm solid fuel rocket ammunition. The carbine has a vague resemblance to an AR type carbine with a high flat-top front sight, fixed carry handle with Williams adjustable rear notch sight, full aluminum construction, full length handguard, contoured pistol grip, and buttstock with smooth plastic buttplate. The left side of the receiver is inscribed "EXPERIMENTAL/MARK I/GYROJET/ROCKET/CARBINE" over the serial number. Like the pistol version, the magazine is fixed in the grip, and the hammer works in reverse, driving the round backwards into a fixed firing pin. Includes leather sling. This carbine was originally sold to a Dr. Robert D. Taylor who was friends with the heads of MBA. Dr. Taylor is listed as the owner of this carbine in the Gyrojet census on gyrojet.net.