The Very Special Specials, .38 and .44, both arrived in the first decade of the 20th century before WWI. The S&W revolver was originally designed to fire the .38 United States Service cartridge (.38 Long Colt). D. B. Wesson suggested the cartridge case be lengthened to allow the powder charge to be increased from 18 grains of black powder to 21.5 grains. The bullet weight was changed from 150 to 158 grains. This new cartridge was called the .38 S&W Special, and with the development of the new cartridge, the factory introduced the .38 Military and Police Model. No one could have foreseen this would be S&W’s most popular revolver, and now, 125 years later, it is still being produced. The same cartridge became the .38-44 Heavy Duty in the early 1930s and was then lengthened to become the .357 Magnum in 1935. A natural progression.