The Model 10 in its classic 4-inch configuration is the most-produced revolver in history. Standard duty barrel length for American law enforcement through most of the 20th century. Round-butt and square-butt variants were catalogued; the 4-inch heavy barrel became the definitive police service revolver. Type: Revolver Action: Double-Action Caliber: .38 Special Capacity: 6 Year introduced: 1899, USA Weight: 36.5 oz Overall length: 9.25" Status: Active Military use: Yes Intended use: duty, law_enforcement, collector, historical