If ever there was a gun idea that had every chance in the world of going wild, the Kimball pistol was it. In 1955, the Army was about to drop the War Baby (or M1 carbine) from use and quantities of both guns and the short little .30-caliber cartridge were on the horizon. The designer knew that Americans loved the idea of feeding a handgun and carbine from the same belt of ammo. So why not a modern automatic pistol chambered for that round. The Kimball pistol was a heavy, solid steel pistol with a delayed blowback action. Beautifully fitted and finished, the Kimball was somewhat reminiscent of the Colt Woodsman with barrel screwed into the receiver and a short slide at the top rear.
They never made more than 300 guns before they went out of print and the maker shut down. In a delayed blowback system with a high pressure cartridge, the action must remain closed until the bullet is long gone and pressures drop. Kimball used a heavy spring (you could hardly rack the slide) since a heavy slide was out of the question. That didn’t get it done, so he milled a groove around the chamber. When fired, the cartridge expanded into this groove and stayed in place until rearward inertia literally swaged the expansion out of the case. This allowed it to move back for extraction and ejection. The nifty little gun broke itself right and left and some of the breaks were catastrophic.
When I mentioned to my editor at the time that I had access to one of the guns, he was quick to go for a shooting session. I was a bit crazier at that point in life, so I set it up. I fired the gun (about a dozen shots, as I recall) and got chronograph results. I also got a group on target, which is probably the only recorded evidence of this curious pistol’s accuracy.