In production since 1899, it is a six-shot double-action revolver with fixed sights. Over its long run it has been available with barrel lengths of 2 in,3 in,4 in,5 in. Barrels of 2.5 inches are also known to have 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. In 1899, the United States Army and Navy placed orders with Smith & Wesson for two to three thousand Model 1899 Hand Ejector revolvers chambered for the M1892.38 Long Colt U. S, in 1902 the.38 Military & Police was introduced, featuring substantial changes. These included major modification and simplification of the internal lockwork and the addition of a locking underlug on the barrel to engage the previously free-standing ejector rod, barrel lengths were 4,5,6, and 6.5 inches with a rounded butt. Serial numbers for the Military & Police ranged from number 1 in the series to 20,975, most of the early M&P revolvers chambered in.38 Special appear to have been sold to the civilian market. By 1904, S&W was offering the.38 M&P with a rounded or square butt, and 4-, 5-, heat treating of cylinders began in 1919. The S&W Model 10 military revolvers produced from 1942 to 1944 had serial numbers with a V prefix and it is noteworthy that early Victory Models did not always have the V prefix. Most Victory Models sent to Britain were fitted with 4-inch or 5-inchbarrels, the Victory Model was used by United States forces during World War II, being chambered in the well-known and popular.38 Special cartridge. Some of these remained in service well into the 1990s with units of the United States Armed Forces. Until the introduction of the Beretta M9 9mm pistol in 1990, U. S. Army helicopter crew members, criminal Investigation Division agents were issued.38 caliber revolvers with two inch barrels. The Victory Model remained in use with Air National Guard tanker, rechambering of. 38-200 cylinders to.38 Special results in oversized chambers, which may cause problems. Lee Harvey Oswald was carrying a re-chambered Victory Model when he was apprehended on November 22,1963, other distinguishing features of the Victory Model revolver are the lanyard loop at the bottom of the grip frame, and the use of smooth walnut grip panels. However some early models did use a grip, most notably the pre-1942 manufacture. After World War II, Smith & Wesson returned to manufacturing the M&P series, in 1957, Smith & Wesson adopted the convention of using numeric designations to distinguish their various models of handguns, and the M&P was renamed the Model 10. The M&P/Model 10 has been available in blued steel finish and nickel finish for most of its production run. The model has also offered throughout the years with both the round butt and square butt, i. e. grip patterns
The lockwork of the first model differed substantially from subsequent versions. The trigger return spring is a flat leaf rather than the coil spring-powered slide used in variations dating from 1905 onwards.