Smith et Wesson 64-3
The Smith and Wesson Model 64 Military and Police revolver is the stainless steel version of its Model 10.
It is a six shot revolver chambered in .38 Special.
The Model 65, is similar but chambered in .357 Magnum, being a stainless steel version of the carbon steel Model 13.
The Model 65 cylinder is longer to accommodate the longer .357 Magnum cartridge.
The Model 65 was in production from 1972 until some time in 2004-2005, and utilized the same standard K-frame (S&W medium frame) as the Model 64. Beginning in 1980, S&W also produced .357 Magnum revolvers on their "medium-large" frame size ("L-frame") to better handle the higher long-term stresses of the magnum loads, calling the larger frame revolver in stainless steel the Model 686.
Photos Littlegun