357 Magnum

The .357 Magnum is a smokeless powder cartridge with a 0.357-inch bullet diameter, introduced in 1935 by Elmer Keith, Phillip B. Sharpe, and Douglas B. Wesson. It was created as a response to Colt's .38 Super Automatic, which was capable of defeating car cover and early ballistic vests. The .357 Magnum is based on the .38 Special cartridge and has the same bullet diameter, but a longer case length to prevent accidental loading in non-compatible revolvers. Its development was influenced by Elmer Keith, who experimented with loading the .38 Special to higher-pressure levels using heavy revolvers and contributed the Keith-style bullet design for increased wounding properties.learn more on wikipedia