Rare 357 long bullet kneckless
 
357 S&W Magnum (9×33mmR), or simply .357 Magnum, is a revolver cartridge with a .357-inch (9.07 mm) bullet diameter. It was created by Elmer Keith, Phillip B. Sharpe,[4] and D. B. Wesson[4] of firearms manufacturers Smith & Wesson and Winchester.[5][6]
It is based upon Smith & Wesson's earlier .38 Special cartridge. The .357 Magnum cartridge was introduced in 1934, and its use has since become widespread. This cartridge started the "Magnum era" of handgun ammunition.[7]
The .357 Magnum cartridge is notable for its highly effective terminal ballistics when used for hunting or defense