text: Smith & Wesson followed 7 years later with the ''Hand Ejector, Model 1896'' in .32 S&W Long caliber, followed by the very similar, yet improved, Model 1899 (later known as the Model 10), which introduced the new .38 Special cartridge. The Model 10 went on to become the best selling handgun of the 20th century, at 6,000,000 units, and the .38 Special is still the most popular chambering for revolvers in the world. These new guns were an improvement over the Colt 1889 design since they incorporated a combined center-pin and ejector rod to lock the cylinder in position. The 1889 did not use a center pin and the cylinder was prone to move out of alignment.
  The Smith & Wesson Model 36 is a 5 shot, revolver chambered for .38 Special. It is one of several models of "J-frame" Smith & Wesson revolvers. It was introduced in 1950, and is still in production. The Model 36 was designed in the era just after World War II, when Smith & Wesson stopped producing war materials and resumed normal production. For the Model 36, they sought to design a revolver that could fire the more powerful .38 Special round in a small, concealable package. Since the older I-frame was not able to handle this load, a new frame was designed, which became the Smith & Wesson J-frame.