The Model 581 is the fixed-sight, blued L-Frame .357 Magnum. Introduced when S&W recognized that sustained full-power .357 Magnum use was wearing out K-Frames prematurely, the L-Frame offered an intermediate size between the K and the large N-Frame. Type: Revolver Action: Double-Action Caliber: .357 Magnum Capacity: 6 Year introduced: 1981, USA Weight: 42 oz Overall length: 9.5" Status: Discontinued Intended use: Duty, Service