38 Spl. with a six round capacity cylinder ... than 100 “Ftiz Conversion” variants of the Colt Detective Special were made. The U.S. Army acquired roughly 5,000 "square butt" Detective ...

It spawned the famed Detective Special, and its frame size was chosen for the Colt Cobra in 1950. The example above, which is chambered in .38 Spl. and has a 4" barrel, was made in 1923.