As stated in Post #2, the cylinder on your .22 Combat Masterpiece was replaced during manufacture. I have two 44 Magnums that were reworked in the same way. You should look at the underside of the extractor to see if the serial number is stamped on it as it was probably replaced also. Finally, there may be a lightly stamped R on the left hand side of the grip frame. Revolvers were often reworked by S&W during manufacture.

Bill