The Model 547 Heavy Barrel 4-inch variant added a full underlug barrel profile to the standard 547, improving the balance and appearance of the unique 9mm clipless extraction revolver. The heavier barrel reduced muzzle rise with 9mm +P loads. Type: Revolver Action: DA/SA Caliber: 9mm Capacity: 6 Year introduced: 1980, USA Weight: 33.5 oz Overall length: 9.5" Status: Discontinued Intended use: Duty, Competition