The Model 66 Combat Magnum 4" is the standard service configuration of S&W's stainless .357 Magnum K-Frame. Widely adopted by law enforcement agencies through the 1970s and 1980s, it represents the apex of the stainless service revolver era. Type: Revolver Action: Double-Action Caliber: 357 Magnum Capacity: 6 Year introduced: 1970, USA Weight: 36 oz Overall length: 9.5" Status: Active Intended use: Service / Law Enforcement