The 4" square-butt heavy barrel Model 10 is the definitive police service revolver configuration — this exact specification was procured by more American law enforcement agencies than perhaps any other handgun specification in history. Type: Revolver Action: Double-Action Caliber: 38 Special Capacity: 6 Year introduced: 1957, USA Weight: 33.5 oz Overall length: 9" Status: Discontinued Intended use: Service / Law Enforcement