One of less than 250 produced circa 1955-1958, the Kimball was a failed attempt at producing a blowback pistol in 30 Carbine, using a series of cut rings in the chamber. In theory, on ignition the casing would swell to fill these rings, delaying extraction long enough for pressure to drop. Of those manufactured, many were destroyed during use by the severe recoil, making examples in this fine of condition even rarer. Blade front and adjustable rear sights, with the Detroit address on the left side of the chamber, serial number on the right, and finely checkered grips. In a hardwood case, French-cut to fit the pistol.