The S&W Model 648 is a K-frame .22 WMR stainless steel target revolver with a 6-inch barrel, designed for small game hunting and precision rimfire shooting. Type: Revolver Action: Double-Action Caliber: .22 WMR Capacity: 6 Year introduced: 1989, USA Weight: 42 oz Overall length: 11" Status: Active Intended use: Target Shooting, Small Game, Competition