[6] The .357 Magnum was collaboratively developed over a period in the early to mid-1930s by a group of individuals as a direct response to Colt's .38 Super Automatic.

At the time, the .38 Super was the only American pistol cartridge capable of defeating automobile cover and the early ballistic vests that were just beginning to emerge in the Interwar period.

Colt's .38 Super Automatic just edged over that velocity and was able to penetrate car doors and vests that bootleggers and gangsters were employing as cover.

Since the frame, cylinder, and barrel were much stronger than the standard .38 Special components, it was capable of withstanding much higher pressures.

The .38-44 HV round, while no longer available, was in most cases the equal of the later .357 Magnum, which works at more than double the pressure of standard .38 Special.

The Keith bullet also employed a large, flat meplat, thus enabling rapid energy transfer for greater wounding properties.

To address this, Smith & Wesson slightly extended the case, which made it impossible to chamber the magnum-power round in a gun not designed for the additional pressure.

Winchester, however, upon experimenting further during the cartridge development, modified the Sharpe bullet shape slightly while keeping its overall contour.

rulings, the .357 Magnum cartridge case can handle up to 300 MPa (44,000 psi) Pmax piezo pressure.

This means that .357 Magnum chambered arms in C.I.P.-regulated countries are currently proof tested at 390 MPa (57,000 psi) PE piezo pressure.

It is a fine small- and medium-game round and is sufficient to hunt deer at reasonable ranges if suitable loadings are used by a competent marksman.

The .357 Magnum has also become popular as a "dual-use" cartridge in short, light rifles like the American Old West lever-actions.

The .357 magnum revolver has been largely replaced by modern, high-capacity semi-automatic pistols for police use, but it is still very popular for backup gun use and among outdoorsmen, security guards, and civilians for hunting, metallic silhouette, target shooting, and self-defense.

[citation needed] Loads are available with energies typically from 400 and 800 foot-pounds force (542 and 1,085 joules) and can be selected for various applications based on desired use and risk assessments.

It is this accuracy and power, and the versatility of also being capable of using less-expensive, milder .38 Special ammunition, that makes a .357 Magnum revolver an excellent gun for many different disciplines, from 20-yard (18 m) precision shooting to long-range falling-plate events.

It was to accommodate these high-pressure, high-power loads that the longer .357 Magnum, together with the stronger revolvers designed to handle it, were developed.

The .357 SIG was developed in 1994 was named "357" to highlight its intended purpose: to duplicate the performance of 125-grain (8.1 g) .357 Magnum loads fired from 4-inch-barreled (102 mm) revolvers, in a cartridge designed to be used in a semi-automatic pistol.