The 4" Model 18 Combat Masterpiece is the standard training-length .22 LR K-Frame, replicating the feel and proportions of a service revolver in an economical rimfire package. It was widely used by police departments and military units for training. Type: Revolver Action: Double-Action Caliber: 22 LR Capacity: 6 Year introduced: 1949, USA Weight: 36 oz Overall length: 9" Status: Discontinued Intended use: Training / Target