.357 Magnum
It was some 68 years ago, on April 8, 1935, that the very first “.357 Magnum” revolver was completed by Smith & Wesson and presented to FBI Director J. Edgar Hoover. It was a seminal moment. The .357 Magnum was the first American cartridge of any kind—handgun, rifle, or shotgun—to bear the label “Magnum.” It was the first of many-to-come, extra-power cartridges to be based on a slightly lengthened version of a previously standard load. For more than two decades after its introduction—until eclipsed by the .44 Magnum—it was the most powerful handgun cartridge produced anywhere in the world, and even today it is still the largest selling and most widely used of all the many handgun cartridges to bear that evocative “Magnum” label.
It is a great cartridge, and substantially more pleasant to shoot than the 44, Clint Eastwood's freehand rendition notwithstanding. Added to this is the ability to plink with the .38 in a .357 firearm, and the popularity is well deserved