The MB Associates (MBA) Gyrojet pistol

In the 1960s, when it looked like everyone would eventually have a jetpack and space would just be a rocket ride away, the Gyrojet pistol was born.

Instead of a conventional cartridge comprising a primer, gunpowder, and a projectile, the Gyrojet was loaded with 13mm (.51-caliber) and later, in the Mk. 2, 12mm (.49-caliber) bullet-shaped rocket projectiles. Solid at the front, the projectiles had a hollow body filled with solid rocket propellant. A primer ignited the propellant, that then exited from four nozzles at the rear of the projectile, each nozzle port angled so that the rocket exhaust would impart spin. Maximum velocity would be more than 1,200 feet per second (fps), in theory giving the projectile 50 percent more energy than a .45 ACP bullet. All this would come from a weapon weighing just over a pound when its internal box magazine was loaded with six rounds, and although the Gyrojet pistol was somewhat large at almost 11 inches long, you were supposed to be able to use it in space, or underwater. Surely, the future had arrived.

There were documented reports of people being shot multiple times at point blank range by a Gyrojet with nothing hurt but their feelings. This was unlikely to have endeared the weapon to the very few soldiers who purchased Gyrojets to carry in Vietnam.

Unfortunately, those who fired it, like those who awaited jet packs and Moon bases, were bound to be disappointed, at best.

Because the military never procured the Gyrojet pistols, or the rifles or carbines the company also developed, some would argue against lumping it into the group of worst military pistols of the 20th century. However, it was developed with the military market in mind, and DoD did fund some of its development and testing before thoroughly rejecting it. At least the Gyrojet pistols were unique. Upon pulling the trigger, a spring-loaded hammer drove the projectile backwards onto a firing pin. When the projectile ignited, it propelled itself back over the hammer, re-cocking the pistol, then out of the barrel toward its target. Unfortunately, unlike a typical cartridge, the Gyrojet’s projectiles were susceptible to dirt and moisture that could clog the nozzle ports or contaminate the propellant. Some projectiles whose propellant didn’t burn properly just dribbled pathetically out of the end of the barrel.

Then there was the issue of stopping power. Even properly operating projectiles didn’t reach full velocity until they were at least 45 feet from the pistol. Like a Saturn V rocket leaving the pad, a Gyrojet projectile took time and distance to build up speed. Exiting the muzzle it had less velocity a BB shot from a Red Ryder air rifle. There were documented reports of people being shot multiple times at point blank range by a Gyrojet with nothing hurt but their feelings. This was unlikely to have endeared the weapon to the very few soldiers who purchased Gyrojets to carry in Vietnam.

Finally, because MBA lacked expensive precision milling machinery that could produce ammunition to tight tolerances, some of the projectiles produced had a manufacturing defect partially blocking one of the nozzle ports. So even if the projectiles were kept scrupulously clean and dry, the Gyrojet could be wildly inaccurate.

One government critic put the problem succinctly, as reported in Mel Carpenter’s An Introduction to MBA Gyrojets and Other Ordnance: “If the target is close enough to hit, you can’t kill it. If you can kill it, you can’t hit it.”

 

Gyrojet Mk. 1 and Mk. 2 Pistol

Type: Semiautomatic pistol; rocket projectiles
Operating system: Blow-forward
Weight: .88 pounds
Length: 10.88 inches
Barrel length: 5 inches
Cartridge: 13mm or 12mm rocket
Muzzle velocity: 100fps (1 foot range) increasing to 1,250 fps
Magazine: 6-round fixed box

 

What, in your opinion, should be the pistol that rounds out the top five worst of the 20th century?