zik, Welcome to the Form. The only S&W with that high a serial number would be a gun shipped to the british early in WW2, probably in late 1941 or early 1942. The correct model number is Model 1905, 4th Change. Collectors sometimes call the gun a Pre-Victory Model, as they were WW2 military guns that preceded the Victory Models that began with serial number V1 when the serial numbers reached 1,000,000 in Jan. 1942 for the Model 1905, 4th changes. Current caliber may still be .38 S&W, as indicated on the barrel stamping, however many of these guns were imported back to the US after WW2 by gun dealers and changed to fire .38 Special cartridges, by boring out the chambers of the cylinders to allow the longer .38 Special founds to chamber. You can order a factory historical letter from Roy Jinks, S&W factory historian, for the gun. It will tell you when it was shipped, to where or whom, and the original configuration of the gun's finish, stocks, etc. Cost is $50. Ed.