The H&R "22 SPECIAL" model was first catalogued circa 1926. The 1st Variation (1926-28) was chambered for 7 shot .22 rimfire (long rifle, long and short) and had the same frame and upper works as the H&R "AUTO EJECTING" model from that era and was equipped with two piece walnut grip panels with a hump at the top ("saw handle"). In late 1928 - 29, the chambering was changed to 9 x .22lr and also 7 x .22 Winchester Rim Fire. This is the 2nd Variation. NOTE: the .22 WRF chambering is extremely scarce - some experts have estimated that only around 200 pieces were made with this chambering. In 1930, the grip panels were changed to rounded top/no hump checkered walnut and this is considered the 3rd Variation (1931- 32). In 1933, the grip frame was changed to the "RICE" type, with a bird's head shaped grip frame and one piece monogrip - attached to the frame by one bolt through the rear of the grip screwing into the now covered back strap. The cylinder now came equipped with a raised rim around the back face - the "H&R SAFETY RIM. This is considered the 4th Variation (1933 - 1938). The 5th Variation (1939 - 1940?) There is the possibility of a 6th Variation with some other changes internally. Markings on the barrel were pretty much consistent, except when the .22 WRF chambering was introduced - the right side was stamped either: ".22 LONG RIFLE CTG" or ".22 W.R.F. CTG". The rear cylinder face for the 7 shot .22 WRF will be marked with a W.R.F. stamp, along with the last three digits of the s/n.
This is a brief description of the development of the "22 SPECIAL" revolver. Any other questions, please ask. I'd like to post some pics, but all of my pics are in High Def. and too large to be attached to this web site.