.357 Magnum - WikiHQ

The .357 Smith & Wesson Magnum, .357 S&W Magnum, .357 Magnum, or 9×33mmR is a rimmed, smokeless powder cartridge with a bullet diameter. It was created by Elmer Keith, Phillip B. Sharpe, and Douglas B. Wesson of firearm manufacturers Smith & Wesson and Winchester. The .357 Magnum cartridge is notable for its highly effective terminal ballistics.

The .357 Magnum cartridge is a magnum cartridge based on Smith & Wesson's earlier .38 Special cartridge. It was introduced in 1935 and has seen widespread use.

Design

thumb|left|250px|[[Marlin Model 1894|Marlin Model 1894C – a carbine in .357 Magnum that is a companion to revolvers]]

thumb|left|250px|Two .357 Magnum cartridges showing bottom and side views

Origins of the cartridge

The .357 Magnum was collaboratively developed 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 emerging in the Interwar period. Tests at the time revealed that those vests defeated any handgun bullet traveling less than about . 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.

Connection to the .38 Special

Though .38 Special and .357 Magnum would seem to be different diameter chamberings, they are in fact identical, as at , they both have the same bullet diameter. The .38 Special nomenclature relates to the previous use of heeled bullets (such as the .38 Short Colt and .38 Long Colt), which were the same diameter as the case. The only external dimensional difference between .38 Special and .357 Magnum is the case length; this was done to prevent the accidental loading of .357 Magnum cartridges into .38 Special revolvers, which are not designed for the .357 Magnum's higher chamber pressure. Case volume was not a factor in the increase in case length, as the .38 Special cartridge was originally a black-powder cartridge, while the .357 Magnum was developed using much denser smokeless powder.

Early experiments and Elmer Keith

Much credit for the .357's early development is given to hunter and experimenter Elmer Keith. Keith's early work in loading the .38 Special to increasingly higher pressure levels was made possible by the availability of heavy, target-shooting–oriented revolvers like the Smith & Wesson .38-44 "Heavy Duty" and "Outdoorsman", .38-caliber revolvers built on .44-caliber frames. The .38-44 HV load used the .38-Special cartridge loaded to a much higher velocity than standard .38-Special ammunition. The .38-44 revolvers were made by using a .44 Special size gun with the barrel bored to accept .357-caliber bullets (the true bullet diameter of the .38 Special) and the cylinder bored to accept cartridges (where the name "38 Special" originated). 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.

Safety considerations

The .357 Magnum addresses safety issues posed by earlier cartridges. Lengthening the cartridge by approximately prevents the high-pressure .357 cartridge from chambering (fitting) in a firearm designed for the shorter, lower-pressure .38 Special. Elmer Keith contributed the Keith-style bullet, which increased the mass of bullet located outside the cartridge case, while leaving more room inside the case for powder. The Keith bullet employed a large, flat meplat for rapid energy transfer to improve wounding capacity. Because this bullet design does not deform like a hollow point, it achieves greater penetration. These characteristics of the Keith bullet make it suitable both for hunting and target shooting.

Development by Smith & Wesson

To reassert itself as the leading law-enforcement armament provider, Smith & Wesson developed the .357 Magnum, with Douglas B. Wesson (grandson of co-founder Daniel B. Wesson)

Dimensions

The .357 Magnum has 1.66 milliliter (26.2 grain ) cartridge case capacity.

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.357 Magnum maximum C.I.P. cartridge dimensions. All sizes in millimeters (mm)

The cartridge headspaces on the rim of the case. The common rifling twist rate for this cartridge is 476 mm (1 in 18.74 in), six grooves, ø lands = 8.79 mm, ø grooves = 9.02 mm, land width = 2.69 mm, and the primer type is small pistol magnum. The cartridge is also used for plinking and target shooting.

The original .357 Magnum load was a bullet with an advertised muzzle velocity of and muzzle energy of . (Muzzle velocity was taken using a large frame revolver with a fairly long barrel of ) Most of today's SAAMI- conforming loads are fairly mild compared to the original mid-1930s load. Today's C.I.P.-compliant loads can duplicate the original mid-1930s load. When using a revolver with a shorter barrel, today's C.I.P. conform maximum loads with a bullet can reach a muzzle velocity of .

For a handgun cartridge, the bolt thrust is a factor in weapons design at C.I.P. conform maximum loads. Revolvers chambered in .357 Magnum can also chamber and fire the shorter .38 Special cartridge. Compared to the .357 Magnum, the .38 Special has lower recoil, noise, and muzzle flash. The use of .38 Special cartridges in .357 Magnum revolvers is common. However, .38 Special ammunition is not typically used in .357 Magnum semi-automatic firearms or rifles, as these require sufficient recoil energy to cycle the action.

The .357 Magnum has also become popular as a "dual-use" cartridge in short, light rifles like the American Old West lever-actions. In a rifle, the bullet will exit the barrel at about , making it far more versatile than the .30 Carbine or the .32-20 Winchester. In the 1930s, it was found to be very effective against steel car doors and ballistic vests, and metal-penetrating rounds were once popular in the United States among highway patrol, state police, sheriffs and other police agencies. The .357 Magnum revolver has been largely replaced by semi-automatic pistols for police use. However, it is still very popular as a backup gun and among outdoorspeople, security guards, and civilians for hunting, metallic silhouette, target shooting, and self-defense. The 9mm Winchester Magnum, which is also known as the 9×29mm, was developed to duplicate the performance of the .357 Magnum in a semi-automatic pistol, as was the .357 SIG cartridge.

Some common performance parameters are shown in the table below for several .357 Magnum loads. Bullet weights ranging from are common. The jacketed hollow-point loads are popular for self-defense, whereas heavier loads are commonly used for hunting. Loads are available with energies typically from 400 to 800 foot-pounds force (542 to 1,085 joules) and can be selected for various applications based on desired use and risk assessments.

{| class="wikitable sortable"

! Manufacturer

! Load

! Mass

! Velocity

! Energy

! Expansion

! Penetration

! PC

! TSC

The .357 Magnum was developed from the earlier .38 Special. This was possible because the .38 Special was introduced in 1898 and originally designed to use black powder, which requires two to five times as much powder by volume to produce the same velocity with the same bullet as smokeless powder. Thus, the .38 Special has a relatively large case capacity, and for lower pressures ( P<sub>max</sub> piezo pressure). The 9×19mm Parabellum was introduced in 1902 and was originally designed to use smokeless powder, and for higher pressures ( P<sub>max</sub> piezo pressure). It therefore produces considerably more energy than the .38, despite its case having less than half the powder capacity. Many .38 Special loads use the same powders at similar charge weights, but because the case is so much larger, light-target loads with fast-burning powders may only fill the case about 1/8 full. Filling the case with slower-burning powders produces much more power, but also much more pressure; far too much pressure for older, smaller-frame revolvers chambered in .38 Special. It was to accommodate these high-pressure, high-power loads that the longer .357 Magnum, together with the stronger revolvers designed to handle it, was developed.

The .357 SIG, developed in 1994, was named "357" to highlight its intended purpose: to duplicate the performance of .357 Magnum loads fired from revolvers, in a cartridge designed to be used in a semi-automatic pistol.

File:Pythons2.jpg|Colt Pythons in 8" and 6" barrels

File:S&W 686 flickr szuppo.jpg|Smith & Wesson Model 686

File:Mitch Barrie - flickr - Ruger GP100.jpg|Ruger GP100 (mod. KGP-161)

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References

External links

".357 Magnum Stopping Power" at Handloads.com
".357 Magnum is a 'do it all' cartridge for hunting and self-defense" by Boyko Nikolov at BulgarianMilitary.com
Ballistics By The Inch .357 Magnum results