Kit gun comments.
Back around 1910 dealer Philip Bekeart placed an order for a variation on the small S&W I-frame. He specified .22 LR, 6" barrel and adjustable sights. S&W shipped the first 292 revolvers in 1911. In 1915 Bekeart's design became a regular cataloged item. Collectors refer to them as the .22/.32 Hand Ejector, .22/.32 Bekeart and .22/.32 Heavy Frame Target (though at 23 ounces it was not very heavy).
By the mid 1930s target shooters wanted heavier guns on medium size frames, such as the Colt Officer's Target and the S&W K22. Sales of the lightweight .22/.32 languished. S&W fitted the I-frame with a 4" barrel with ramp front sight and adjustable rear sight. They called the result the Kit Gun, meaning a gun a hunter, fisherman, or camper could pack along with other outdoor gear in a kit bag. The concept proved very popular, and in fact Kit Guns are being built to this day.
There have been many variations, in .22 LR and .22 Mag, with 2", 3", 3V2" and 4" barrels, with blued or nickeled carbon steel, stainless steel, aluminum alloy and scandium frames, with 6-shot and (currently) with 7- (.22 Mag) and 8-shot (.22 LR) cylinders.
By 1950 S&W felt there was a market for a small-frame, .38 Special revolver. The I-frame cylinder at 1.25" long was too short, so S&W designed a new size, the J-frame, with a longer cylinder and longer frame window. However I-frame production continued through the '50s, used in the Kit Gun and for .32 Long and .38 S&W models.