The S&W Model 19 is a revolver produced by Smith & Wesson on its K-frame platform. The model 19 is chambered for .357 Magnum. The K-frame is somewhat smaller and lighter than the original N-frame .357, usually known as the S&W Model 27.
The Model 19 was produced in blued carbon steel or nickel-plated steel with wood or rubber combat grips, an adjustable rear sight, semi-target hammer, serrated combat-type trigger, and was available in 2.5" (3": Model 66â€”rare), 4", or 6-inch barrel lengths. The weights are 30.5 ounces, 36 ounces, and 39 ounces, respectively. The 2.5- and 3-inch barrel versions had a round butts, while the others had square butts.
The Model 19 was produced from 1957 (first model number stampings) to November 1999. The Model 66 was produced from 1970 until 2005. The Model 66 differed by its use of stainless steel and its smooth target-type trigger. The Model 19 and the Model 66 had the same trigger options.
Engineering changes were designated with a "dash-" number after the model number. The engineering changes are as follows:
19 (1957): Stamping of model number.
19-1 (1959): Change extractor rod, right to left-hand thread.
19-2 (1961): Cylinder stop changed, delete triggerguard screw.
(1963): Introduce 6" barrel.
(1963): 50 manufactured with 2.5" barrel, serial range K544672â€“K544721.
(1966): Introduce 2.5" barrel as standard.
19-3 (1967): Relocation of rear sight leaf screw.
(1968): Delete diamond-insert grip.
19-4 (1977): Change gas ring from yoke to cylinder. (Not really an "improvement". It did make it slightly easier to clean if there was heavy leading, but basically was a cost-cutting measure.)
19-5 (1982): Eliminate cylinder counterbore.
19-6 (????): ??
1986 S&W model 66-2 6" Barrel
66 (1970): Stamping of each model.
66-1 (1977): Changed the gas ring from the yoke to the cylinder.
66-2 (1982): Eliminated pinned and recessed, slightly lengthened cylinder.
66-3 (1986): New yoke retention system/radius stud package/hammer nose bushing/floating hand.
66-4 (1994): Change rear sight leaf, drill and tap frame, introduce Hogue grips, change extractor.
66-5 (1998): Change in frame design: eliminate cylinder stop stud/eliminate serrated tangs/change to MIM hammer with floating firing pin/change internal lockwork.
66-6 (2002): Introduced internal lock.
66-7 (?): Two piece barrel and internal lock,