The original Model 66 served law enforcement for nearly 50 years since it was introduced in 1970. Built on the S&W K-Frame and chambered in .357 Magnum, with the 6-round capacity, it was recognized for its lightweight and durability. The gun was very similar to the Model 19, but with a stainless-steel frame instead of a frame made of carbon steel. Many changes to the design were made over the years and the first update was the Model 66-1. The company withdrew the gun from the market in the mid-2000s but on customers' demand, the gun was returned in 2014 with The Model 66-8, indicating the 8 major versions. The new Model 66 is available in two barrels’ lengths, 4.25 inches and 2.75 inches on one of the new Model 66 - a Combat Magnum version. Some other features of the new Model 66 are full top strap and barrel serrations, ball-detent lock-up, and a 2-piece barrel. It is a single/double-action revolver. This is a revolver with a famous past that still survives challenges and new demands even today.