| .357 SIG | ||
|---|---|---|
 ,.357 SIG cartridge |
||
| Type | Pistol | |
| Place of origin |  Switzerland United States |
|
| Production history | ||
| Designer | SIGARMS/Federal Cartridge Co. | |
| Designed | 1994 | |
| Produced | 1994 to present | |
| Specifications | ||
| Parent case | .40 S&W | |
| Case type | Rimless, bottleneck | |
| Bullet diameter | 9.03 mm (0.356 in) | |
| Neck diameter | 9.68 mm (0.381 in) | |
| Shoulder diameter | 10.77 mm (0.424 in) | |
| Base diameter | 10.77 mm (0.424 in) | |
| Rim diameter | 10.77 mm (0.424 in) | |
| Rim thickness | 1.40 mm (0.055 in) | |
| Case length | 21.97 mm (0.865 in) | |
| Overall length | 28.96 mm (1.140 in) | |
| Case capacity | 1.27 cm³ (20 gr H2O) | |
| Rifling twist | 406 mm (1 in 16 in) | |
| Primer type | Small pistol | |
| Maximum pressure | 275.8 MPa (40,000 psi) | |
| Ballistic performance | ||
| Bullet weight/type | Velocity | Energy |
| 60 gr (3.9 g) Special Application Ammunition | 2,410 ft/s (730 m/s) | 774 ft·lbf (1,049 J) |
| 115 gr (7.5 g) Bonded defense JHP | 1,550 ft/s (470 m/s) | 614 ft·lbf (832 J) |
| 125 gr (8.1 g) FMJ-FP Match and Bonded defense JHP | 1,450 ft/s (440 m/s) | 584 ft·lbf (792 J) |
| 147 gr (9.5 g) Bonded defense JHP | 1,250 ft/s (380 m/s) | 510 ft·lbf (690 J) |
| 147 gr (9.5 g) FMJ-FP | 1,255 ft/s (383 m/s) | 514 ft·lbf (697 J) |
| Test barrel length: 4 in (102 mm) rifled barrel. Source: DoubleTap Ammunition, RBCD Special Application Ammunition, C.I.P.[1] |
||
The .357 SIG pistol cartridge is the product of Swiss firearms manufacturer SIG-Sauer, in cooperation with the American ammunition manufacturer Federal Cartridge. While it is based on a .40 S&W case necked down to accept 0.355-inch (9.0 mm) bullets, the .357 SIG brass is longer. With a good hollow point bullet, the .357 SIG penetrates well and has sufficient energy transfer to impart hydrostatic shock in living targets.[2][3][4]
Contents |
History
Developed in 1994, the new cartridge was named "357" to highlight its purpose: to duplicate the performance of 125-grain (8.1 g) .357 Magnum loads fired from 4-inch (100 mm) barreled revolvers, in a cartridge designed to be used in a semi-automatic pistol. Performance is similar to the 9x23mm Winchester.
The .357 SIG provided a self-defense cartridge close in performance to a 125 gr .357 Magnum, but from a smaller and more concealable semi-automatic pistol.
The .357 SIG was the first modern bottleneck commercial handgun cartridge since the early 1960s, when Remington introduced the unsuccessful .22 Remington Jet (1961), which necked a .357 Magnum case down to a .22 caliber bullet, and the .221 Remington Fireball (1963). Soon after the .357 SIG, other bottleneck commercial handgun cartridges appeared: the .400 Corbon (1996), necking the .45 ACP down to .40 caliber; the .440 Corbon (1998), necking down the .50 AE to .44 caliber, the .25 NAA (1999), necking the .32 ACP down to .25 caliber; and the .32 NAA (2002), necking the .380 ACP down to .32 caliber.
Cartridge dimensions
The .357 SIG has 1.27 ml (19.5 grains) H2O cartridge case capacity.
.357 SIG maximum C.I.P. cartridge dimensions.[1] All sizes in millimeters (mm).
Americans would define the shoulder angle at alpha/2=18 degrees. The common rifling twist rate for this cartridge is 406 mm (1 in 16 in), 6 grooves, Ø lands=8.71 mm, Ø grooves=9.02 mm, land width=2.69 mm and the primer type is small pistol.
According to the official C.I.P. (Commission Internationale Permanente Pour L'Epreuve Des Armes A Feu Portatives) guidelines the .357 SIG case can handle up to 305 MPa (44,236 psi) piezo pressure. In C.I.P. regulated countries every pistol cartridge combo has to be proofed at 130% of this maximum C.I.P. pressure to certify for sale to consumers.
The SAAMI pressure limit for the .357 SIG is set at 275.80 MPa (40,000 psi), piezo pressure.[5]
Conversions
Most .40 S&W pistols can be converted to .357 SIG by replacing the barrel, but sometimes the recoil spring must be changed as well. Pistols with especially strong recoil springs can accept either cartridge with a barrel change. Magazines will freely interchange between the two cartridges in most pistols. .357 SIG barrel kits have allowed this cartridge to gain in popularity among handgun owners. However, the .357 SIG is loaded to higher pressures than the .40 S&W (the C.I.P. and the SAAMI pressure limits for .40 S&W are 225 MPa and 35,000 psi), and may not be suitable for use in all .40 S&W-chambered pistols due to the increase in bolt thrust.
Characteristics
The goal of the .357 SIG project was to offer a level of performance equal to the highly effective 125 grains (8.1 g) .357 Magnum load [6][7]. The .357 SIG accomplishes this with a 125 grains (8.1 g) bullet at a muzzle velociy of 1,450 feet per second (440 m/s) out of a 4 in (102 mm) barrel, which is generally identical to the velocity achieved by standard factory 125 grains (8.1 g)r .357 Magnum loads out of a 4 in (102 mm) revolver barrel. The .357 SIG gains extra muzzle velocity when fired from a longer barrel, like an after-market drop-in 6 in (152 mm) barrel.
With a simplistic approach to physics, recoil being directly proportional to "muzzle velocity x bullet mass" (Newton's third law), the recoil of the .357 SIG is equal to or slightly less than that of the .40 S&W, and less than that of the full-power 10 mm Auto loads or the original .357 Magnum [8], Handgun Recoil table as well as Federal and [9]. This simple approach to recoil is only part of the story as it is not only the properties of the bullet that produce recoil, a more important effect is the rocket like blast of propellant gases coming out of the barrel, after the bullet leaves the muzzle, that plays a greater role in the recoil felt. A more accurate view on recoil is that it is proportional to the mass of all ejecta x velocity of ejecta.[10] Even so, recoil calculated in this manner is only the starting point in a comparison with the .357 Magnum cartridge, since the latter is used in a revolver, in which all the recoil energy is felt recoil, while the .357 SIG cartridge is frequently used in a semi-automatic pistol of recoil operation, in which a significant portion of the recoil energy is diverted to cycle the action.
In comparing the energy levels of premium self defense ammunition the muzzle energy of 584 ft.lbs (792 J) of the 125 grains (8.1 g) 1,450 feet per second (440 m/s) .357 SIG load is higher than either the 475 ft·lbf (644 J) generated by a 155 grains (10.0 g) 1,175 feet per second (358 m/s) Speer GoldDot .40 S&W load or the 400 ft·lbf (540 J) generated by a 180 grains (12 g) 985 feet per second (300 m/s) Speer GoldDot .40 S&W load.[11]
Like the 10 mm Auto, the .357 SIG can be down-loaded to reduce recoil, to the point where recoil is similar to that of a 9x19mm Parabellum. However, since the .357 SIG uses bullets that are generally the same as those used in the 9 mm Para,[12] downloading it to this point would defeat the purpose of having the SIG cartridge in the first place, as recoil and ballistics would be identical to the less-powerful 9 mm cartridge.
Because the .357 SIG fires at relatively high pressures, muzzle flash and noise are significant with standard loads, even with longer barrels. Utilizing loads with specialized powders and experimenting with different bullet weights can reduce flash.
Handloading
Although the .357 SIG design is based on the .40 S&W case, handloaders cannot form .40 S&W cases into .357 SIG brass. While the two cases are identical in rim diameter, using the .40 S&W case will result in a case that is approximately 0.020 in (0.508 mm) too short. Unlike most bottlenecked cartridges, the .357 SIG headspaces on the case mouth.[12] Cartridges that are too short can result in malfunctions which may cause serious injury. Furthermore, the SAAMI limit is lower for the .40 cartridge at 35,000 PSI, than the 40,000 PSI for the .357 SIG.
While some people have attempted to form .357 SIG cases from 10 mm Auto cases, this is rather impractical. First of all, the change in primer type (10 mm uses large pistol primers, .357 SIG uses small pistol primers) would require that known recipes be scrapped, and second, the cost of using expensive 10 mm brass for such a purpose would certainly defeat the goal of saving money by reloading. Both unfired and once-fired .357 SIG brass are readily available at low cost from several well-known vendors.
Choosing the correct bullet type is extremely important when handloading the .357 SIG cartridge. The short neck of the casing makes the use of standard round-nosed bullets impractical: there is simply not enough flat area for the neck to "grip" the bullet, so flat-point bullets are used. Various 9 mm hollow-point bullets can also be successfully used, but due to the wide variety of choice, the chances of success vary from one brand to another.
Performance
Because of its relatively high velocity for a handgun round, the .357 SIG has a very flat trajectory, extending the effective range. However, it does not quite reach the performance of the .357 Magnum with bullets heavier than 125 grains (8.1 g). Offsetting this general slight disadvantage in performance is that semi-automatic pistols tend to carry considerably more ammunition than revolvers.
Like the 7.62x25mm Tokarev, the .357 SIG works well when shooting through barriers. There has been a documented case in Texas where a police officer's .45 round did not penetrate a tractor-trailer's shell, but a .357 SIG round from a backup officer's gun did, killing the suspect inside. The round's ability to penetrate barriers is the main reason for its adoption by law enforcement agencies. However, other documented police shootings have confirmed the round's ability to not overpenetrate the body, even though ballistic gelatin shows 16 inches (410 mm) of penetration through heavy clothing (125 grain Speer Gold Dot). The Virginia State Police have had several documented officer-related shootings involving the .357 SIG, and in every case, not only were the felons stopped instantly with one shot (except one who was shot several times while attempting to murder an officer), the bullet either didn't exit the felon, or was stopped in the clothing upon exiting, proving that even at such high velocities, the round when used with adequate expanding hollowpoints will not over penetrate soft tissue. The same department has also reported that attacking dogs have been stopped dead in their tracks by a single shot, whereas the former subsonic 147 grain 9 mm duty rounds would require multiple shots to incapacitate the animals.[13] The energy available in the .357 SIG is sufficient for imparting hydrostatic shock with well designed bullets.[2][3][14] Recent publication of human autopsy results has demonstrated brain hemorrhaging from fatal hits to the chest with 9mm bullets.[4]
The reputation that the .357 SIG round had for losing its crimp (allowing for bullet setback) was partially true when the cartridge was new and ammunition manufacturers were just beginning to produce the round. These problems have since been corrected by major manufacturers. As a result, the round now exhibits nominal setback characteristics, similar to other cartridges.[citation needed]
The bottleneck shape of the .357 SIG cartridge makes feeding problems almost non-existent.[citation needed] This is because the bullet is channeled through the larger chamber before being seated entirely as the slide goes into full battery. Flat point bullets are seldom used with other autoloader platforms because of feeding problems; however, such bullets are commonly seen in the .357 SIG chambering and are quite reliable, as are hollow-point bullets.
One disadvantage of the .357 SIG is that it fires a .355" bullet at higher velocities than most bullets of that caliber are designed for. Very few bullets have been designed specifically for the .357 SIG, and .357 Magnum bullets that are designed for the same velocity range cannot be used due to their slightly larger diameter. Because of this, there are fewer ammunition choices in .357 SIG than one might expect for a cartridge using .355" bullets.
Another potential drawback of the .357 SIG is its somewhat harsh treatment of pistols that are not designed to handle its high pressure that coupled to its case head area yields a high bolt thrust[15] for a semi-automatic service handgun cartridge. Firing .357 SIG through modified pistols that were originally designed to fire the .40 S&W can accelerate wear.
The "Accurate Powder" reloading manuals claims that it is "without a doubt the most ballistically consistent handgun cartridge we have ever worked with."[5]
Implementation
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This section does not cite any references or sources. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (April 2008) |
The SIG-Sauer P229 in .357 SIG is currently one of the standard issue firearms carried by special agents and Uniformed Division officers of the United States Secret Service, the Bastrop County Texas Sheriff's Office, the North Carolina State Highway Patrol, Delaware State Police, Rhode Island State Police, Alameda County Sheriff's Office, Virginia State Police, Federal Air Marshals and the Treasury Inspector General for Tax Administration. The Pennsylvania Game Commission replaced the .357 Mag. with the .357 SIG. In most cases, it has replaced 10 mm, .40 S&W and 9 mm loads. In 1995, the Texas Department of Public Safety became the first government agency to implement the .357 SIG. The Tennessee Highway Patrol presently issues the Glock 31 pistol chambered in .357 SIG. The Bedford Heights Police Department (OH) currently issues the Glock 31/32 in .357 SIG. The Elloree Police Department in South Carolina Elloree Policealso issues the Glock 31, .357 SIG and the Madison Police Department in Madison, WV issues the Glock 32 in .357 SIG.
See also
References
- ^ a b "C.I.P. decisions, texts and tables - free current C.I.P. CD-ROM version download (ZIP and RAR format)". http://www.cip-bp.org/index.php?id=tdcc-telechargement. Retrieved 2008-10-17.
- ^ a b "Scientific Evidence for Hydrostatic Shock". http://arxiv.org/abs/0803.3051.
- ^ a b Sturtevant B, Shock Wave Effects in Biomechanics, Sadhana, 23: 579-596, 1998.
- ^ a b Krasja, J. Příčiny vzniku perikapilárních hemoragií v mozku při střelných poraněních (The causes of peripheral hemorrhages in the brain due to firearm injuries), Institute of Forensic Medicine, Faculty of Medicine, Masaryk University, Brno, Czech Republic, 2009.
- ^ a b ".357 SIG" data from Accurate Powder. Accessed 2009-06-09. Archived 2009-06-11.
- ^ recorded results in Street Stoppers pg 173 .357 Magnum and Handgun Stopping Power by Marshall & Sanow
- ^ Quantifying handgun bullet effectiveness in humans
- ^ Lyman Reloading Handbook, 43rd Edition
- ^ Street Stoppers page 142 .357 SIG Recoil
- ^ http://www.thehighroad.org/showthread.php?t=69535
- ^ Midway USA page
- ^ a b Lyman Reloading Handbook, 48th edition, 2002, Lyman Products Corp.
- ^ Ayoob, Massad. (2002). The Gun Digest Book of Combat Handgunnery, 5th edition: Krause Publications. ISBN 0-87349-485-7
- ^ Courtney A, Courtney M: Links between traumatic brain injury and ballistic pressure waves originating in the thoracic cavity and extremities. Brain Injury 21(7): 657-662, 2007.
- ^ "A Look at Bolt Lug Strength By Dan Lilja". Archived from the original on 2009-04-19. http://www.webcitation.org/5g9ssS85o. Retrieved 2009-03-17.
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