…the Gyrojet being the '60s weapon that fired small spin-stabilized rockets instead of bullets.
But the thought struck me the other day: why did the rifle/carbine versions have a longer barrel than the pistol version? The rocket projectiles were (naturally) self-propelled, still accelerating after leaving the weapon, and the spin was imparted by angled exhaust ports, not by engaging barrel rifling.
I’m assuming I’m missing some technical aspect behind the Gyrojet rifle’s design—but I can’t think of what. Can anyone enlighten me?
A rifle is easier to aim accurately and hold steady than a pistol. Not sure why they bothered with separate rifle/carbine versions, though.
One problem with rocket propelled bullets is the time they to come up to speed. The pistol barrel was short so that it would be a pistol, a gun held with one hand of reasonable size. The rifle barrel barrel is longer and the bullet will leave the barrel with greater velocity and more spin, thus more stablility and greater accuracy. One reason this never took off was the rocket powered bullets sometimes not getting up to speed fast enough and just falling out of the end of the gun.
Since the Gyrojet projectile/rocket continued to gain velocity for many yards after it left the barrel, the actual barrel length didn’t effect max speed.
Additional barrel length and a shoulder stock would make the carbine version easier to hold on target. It would also have an increased sight radius (the distance between the front and rear sight) which would normally result in tighter groups but the inconsistent performance of the Gyrojet’s projectiles jets could cause corkscrewing and high/low fliers. I would say it threw fast knuckleballs. Long range accuracy was a crapshoot.
The only designed that worked as advertized and became a commercial success was the A/P25S-5A GYROJET Rocket- Signal Kit and it didn’t have a barrel.
