The 4" Model 15 Combat Masterpiece was the most common configuration — a service-length adjustable-sight K-Frame that served as both a duty revolver and a precision training gun. The U.S. Air Force used this configuration as its standard issue sidearm. Type: Revolver Action: Double-Action Caliber: 38 Special Capacity: 6 Year introduced: 1949, USA Weight: 34 oz Overall length: 9" Status: Discontinued Military use: Yes Intended use: Service / Military