I have a 1935 manufactured Colt Official Police in .22 caliber and a 6" barrel. It is a lot of fun to shoot although you can definitely feel the weight from only having the standard weight barrel and cylinder reamed to .22 dimensions. It would be interesting to see how many of that model that Colt's sold compared to their .38 version. Both S&W and Colt's had target grade/adjustable sight .22 revolvers in their lineups from the 1930's onward but they didn't really market them as "trainers" until around the time that the .38 Combat Masterpiece became available and a lot of officers switched from the old M&P's to that model. Then the .22 Combat Masterpiece made a lot of sense.