The Smith & Wesson Model 10, previously known as the Smith & Wesson Military & Police or the Smith & Wesson Victory Model, is a .38-caliber revolver developed from the Smith & Wesson .38 Hand Ejector Model of 1889. In production since 1899, it is a fixed-sight, six-shot handgun with a fluted cylinder. Over its long production run it has been available with barrel lengths of 2 in (51 mm), 3 in (76 mm), 4 in (100 mm), 5 in (130 mm), and 6 in (150 mm). Barrels of 2.5 inches (64 mm) are also known to have been made for special contracts. Some 6,000,000 of the type have been produced over the years, making it the most popular centerfire revolver of the 20th century.