The Smith & Wesson (S&W) Model 12 is .38 Special revolver on Smith & Wesson's K-frame (medium size) platform. It is an aluminium alloy-frame version of the Smith & Wesson M&P. It was made from 1953 to 1986 in both two- and four-inch barrel configurations. It weighs 524 grams (19 oz) unloaded.
The Model 12 variants 12-1, 12-2, and 12-3 had a slimmer frame than the standard steel K-frame revolver. The final version, the Model 12-4, had the same frame thickness of the other K-frames. It also featured a rounded butt.
Since the gun is an alloy frame, it is not advisable to use +P ammunition since the frame may stretch during shooting. This is apparent when the primers have elongated firing pin marks. Very early versions have aluminum cylinders and should not be fired.
The two-inch barrel Model 12 is also called a snub-nose. Detectives and others with licenses to carry find the snub-nose type of revolver, such as the vintage Model 12, concealable, lighter in weight than its longer-barreled twins, and in an emergency, easy to deploy with its trim wood grips and round butt. It is also a proven performer as a back-up pistol for some officers, who carry a larger caliber pistol at their waist.
The Model 12 is most often found to have some wear on its bluing due to age, but this wear does not detract from either its function or its value as a vintage concealed-carry piece. An important earmark is the factory stamp Mod-12 on the frame inside the yoke. Also on the inside of the yoke is the revolver's serial number, which is repeated verbatim on the base of the butt. The Model 12 holds its market value nicely and is highly collectible. As with most older revolvers, a reputable gunsmith should check its functioning prior to purchase.