a model # and/or picture would help a lot. If it was made after 1957, the model # would be stamped on the frame. Just open the cylinder and look on the frame, just ahead of the cylinder.
+1. The gun could be worth anywhere from ~$350 to $3,000+ depending on the model. There is a very active community of S&W collectors who have documented the different models very well, so the values can vary tremendously. The model number stamp will consist of the text MOD. followed by a 2- or 3-digit model number, and possibly a dash and another number.
There are a
few S&W .357 Magnum revolvers out there that predate model numbers, however. If there's no number, here's how to quickly identify them.
.357 Combat Magnum (pre-Model 19): Medium-sized K frame, "K" serial number prefix.
.357 Magnum, non-registered (pre-Model 27): Large N frame, high polished blue finish, distinctive checkered topstrap, serrated rear sight leaf, no serial number prefix (prewar) or "S" prefix (postwar), no additional number stamped inside crane.
.357 Registered Magnum: Same as above but with registration number stamped inside crane and no "S" prefix, since all were prewar. Very rare and valuable.
.357 Highway Patrolman (pre-Model 28): Similiar to .357 Magnum but with satin blued finish, smooth topstrap, smooth rear sight leaf, and the words "HIGHWAY PATROLMAN" roll-stamped on the side of the barrel.
