.357 SIG explained

.357 SIG
Origin:Switzerland
United States
Type:Pistol
Designer:SIGARMS / Federal Premium Ammunition
Design Date:1994
Production Date:1994–present
Parent:10mm Auto
Case Type:Rimless, bottleneck
Is Si Specs:yes
Bullet:9.02
Land:8.71
Neck:9.68
Shoulder:10.77
Base:10.77
Rim Dia:10.77
Rim Thick:1.40
Case Length:21.97
Length:28.96
Case Capacity:1.27
Rifling:406 mm (1 in 16 in)
Primer:Small pistol
Max Pressure:305.0
Pressure Method:C.I.P.
Max Pressure2:275.8
Pressure Method2:SAAMI
Bwunit:gram
Bw1:8.1
Btype1:Federal FMJ
Vel1:1350
En1:506
Bw2:8.1
Btype2:Doubletap FMJ-FP
Vel2:1450
En2:583
Bw3:5.83
Btype3:Grizzly JHP
Vel3:1900
En3:721
Bw4:8.1
Btype4:Underwood TMJ
Vel4:1475
En4:604
Bw5:6.48
Btype5:Cor-bon PB
Vel5:1600
En5:568
Balsrc:4.5" barrel for DoubleTap Ammunition, NO BARREL LENGTH GIVEN BY Grizzly Cartridge and Underwood Ammo m and 4.0" barrel for Corbon PB. See also C.I.P.

The .357 SIG (designated as the 357 Sig by the SAAMI[1] and 357 SIG by the C.I.P.[2] or 9×22 mm in official metric notation) is a bottlenecked rimless centrefire handgun cartridge developed by the Swiss-German firearms manufacturer SIG Sauer, in cooperation with ammunition manufacturer Federal Premium. The cartridge is used by a number of law enforcement agencies.[3]

History

The .357 SIG is based on a necked-down 10mm Auto case, foregoing the large pistol primer utilized by the 10mm Auto in favor of the small pistol primer used in many common self-defense rounds, such as .40 S&W, .38 Special, 9 mm and other similarly-sized cartridges. Excluding specialized wildcat cartridges used in competition shooting — e.g., the 9×25mm Dillon, which necked a 10mm Auto case down to a 9 mm bullet — the .357 SIG was the first modern bottlenecked handgun cartridge to become commercially available since the 1961 introduction of Winchester's now-obsolete .256 Winchester Magnum, a .257 caliber round based on the .357 Magnum. Later the same year Remington and Smith & Wesson began jointly developing a similar round and, before the year's end, introduced the .22 Remington Jet, a .357 Magnum case necked down to accommodate a .22 caliber bullet.

Despite its favorable ballistics and performance, the .357 SIG has not achieved the widespread adoption seen with similar cartridges. One factor preventing the round from achieving greater popularity could be the cost of the ammunition, which frequently reaches double the expense of 9 mm, .40 S&W or .45 ACP ammunition. Because of this, as well as availability issues, some law enforcement agencies that previously adopted the cartridge have reportedly began to move away from the .357 SIG in favor of more common rounds with comparable performance.[4] [5] [6] [7]

Cartridge dimensions

The .357 SIG has 1.27 ml (19.5 grains H2O) cartridge case capacity.

.357 SIG maximum C.I.P. cartridge dimensions.[2] All sizes in millimeters.

Several sources have published contradicting information regarding .357 SIG headspacing.[8] This is due to the cartridge having been originally designed as a .357 (9.02 mm) round, but then rapidly adapted to the .355 (9 mm) bullet. According to the official C.I.P. (Commission Internationale Permanente Pour L'Epreuve Des Armes A Feu Portatives) 2008 revised documents, the .357 SIG headspaces on the case mouth (H2).[9] Some US sources are in conflict with this standard.[10] However, the cartridge and chamber drawing in the ANSI/SAAMI American National Standards also clearly shows the cartridge headspacing on the case mouth.[11] Likewise, US reloading supplier Lyman has published that the .357 SIG headspaces on the case mouth.

According to the C.I.P. rulings 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.[12]

Conversions

While it is based on a 10 mm case necked down to accept 0.355inches bullets, the .357 SIG cartridge case is slightly longer than the .40 S&W by 0.009inches to 0.02inches total. Most .40 S&W pistols can be converted to .357 SIG by replacing the barrel, but sometimes the recoil spring must also be changed. 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.

Performance

The table below shows common performance parameters for several .357 SIG loads. Bullet weights ranging from 115gr150gr have been offered. Loads are available with energies from to, and penetration depths from to over are available for various applications and risk assessments. Underwood now also offers a standard pressure 65 gr .357 SIG Xtreme Defender (XD) round with a muzzle velocity of 2,100 fps, muzzle energy of 636 ft. lbs. and a penetration depth of 17.5 inches.

ManufacturerLoadMassVelocityEnergyExpansion[13] PenetrationPCTSC
TritonQuik-Shok115gr1425ft/s 518ftlbf frag9inches4.1cuin43.2cuin (est)
WinchesterRanger T125gr1385ft/s 532ftlbf0.75inches11.5inches5.1cuin45cuin (est)
FederalPremium JHP 125gr1430ft/s 568ftlbf0.62inches12.7inches3.8cuin49.5cuin (est)
SpeerGold Dot JHP125gr 1385ft/s 532ftlbf0.68inches16.5inches6cuin45cuin (est)
Remington JHP125gr1350ft/s506ftlbf0.57inches14.3inches3.6cuin41.7cuin (est)
FederalPremium JHP150gr 1210ft/s488ftlbf0.6inches15inches4.2cuin 39.4cuin (est)
UnderwoodGold Dot JHP125gr 1450ft/s 583ftlbf0.75inches16.5inches6cuin45cuin (est)


Key:
Expansion – expanded bullet diameter (ballistic gelatin).
Penetration – penetration depth (ballistic gelatin).
PC – permanent cavity volume (ballistic gelatin, FBI method).
TSC – temporary stretch cavity volume (ballistic gelatin).

Because of its relatively high velocity[14] for a handgun round, the .357 SIG has an unusually flat trajectory, extending the effective range. However, it does not quite reach the performance of the .357 Magnum with bullets heavier than 125gr. Offsetting this general slight disadvantage in performance is that semi-automatic pistols tend to carry considerably more ammunition than revolvers.

The Virginia State Police has reported that attacking dogs have been stopped dead in their tracks by a single shot, whereas the former 147 grain 9 mm duty rounds would require multiple shots to incapacitate the animals.[15] Proponents of the hydrostatic shock theory contend that the energy available in the .357 SIG is sufficient for imparting hydrostatic shock with well-designed bullets.[16] [17] [18] Users have commented, "We're really impressed with the stopping power of the .357 SIG round."[3]

The bottleneck shape of the .357 SIG cartridge makes feeding problems almost non-existent.[19]

The Accurate Powder reloading manual claims that it is "without a doubt the most ballistically consistent handgun cartridge we have ever worked with".

Characteristics

The goal of the .357 SIG project was to offer a level of performance equal to the highly effective 125gr .357 Magnum load.[20] [21] Measurements of standard factory .357 SIG cartridges loaded with 125gr bullets showed approximate muzzle velocities of 1450ft/s out of a 4inches barrel, which is essentially identical to the .357 Magnum with the same bullet weight and barrel length.[22] [23] These measurements were performed with a Thompson Center Encore 1842 break-action, single-shot pistol-rifle, preventing differing barrel length definitions between semi-automatic pistols and revolvers giving revolvers a potential muzzle velocity advantage.[24]

With a simplistic approach to physics, recoil being directly proportional to "muzzle velocity × bullet mass" (due to conservation of momentum), 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 10mm Auto loads or the original .357 Magnum,[25] This simple approach to recoil is incomplete since the properties of the bullet alone do not determine the felt recoil, but also the rocket-like blast of propellant gases coming out of the barrel after the bullet leaves the muzzle.[26] A more accurate view on recoil is that it is proportional to the mass of all ejecta × velocity of ejecta.[27]

In comparing the energy levels of premium self-defense ammunition, the muzzle energy of 584ft·lbf of the 1450ft/s .357 SIG load is greater than either the 475ft·lbf generated by a 1175ft/s Speer GoldDot .40 S&W load or the 400ft·lbf generated by a 985ft/s Speer GoldDot .40 S&W load.[28]

Implementation

In 1994, Sig released the P229 pistol, the first production handgun introduced that was chambered in .357 SIG and specifically designed to handle the higher pressures of that round.[29]

However, in 2013 the Texas DPS decided to replace their .357 SIG handguns with 9 mm handguns.[30] The ability to carry more rounds per magazine (9 mm vs. .357 SIG) in a lighter gun were among the stated reasons for the change.[31] That transition was suspended after recruits in the A-2014 class, the first to train with the new S&W M&P 9 mm polymer handguns, experienced numerous malfunctions with those weapons.[32]

The newer SIG Sauer P229 in .357 SIG has been adopted for use by agents and officers of the following national and state law enforcement organizations (LEO):

See also

External links

Notes and References

  1. Web site: SAAMI 357 Sig cartridge and chamber drawings. saami.org. 24 April 2018. dead. https://web.archive.org/web/20140714212802/http://www.saami.org/PubResources/CC_Drawings/Pistol/357%20Sig.pdf. 2014-07-14.
  2. Web site: C.I.P. TDCC datasheet 357 SIG. cip-bobp.org. 24 April 2018. live. https://web.archive.org/web/20160804073827/http://www.cip-bobp.org/homologation/uploads/tdcc/tab-iv/tabivcal-en-page53.pdf. 4 August 2016.
  3. The Gun Digest Book of Sig-Sauer: a complete look at Sig-Sauer pistols. Massad Ayoob. 2004. pp. 51–53.
  4. Web site: Ammo Showdown: .357 Sig vs .40S&W. JM4 Tactical. 25 October 2017 .
  5. Web site: .357 Sig: What's the Point of this Cartridge?. 23 August 2018 .
  6. Web site: Why .357 Sig Never Caught on. 28 March 2014 .
  7. Web site: The Secret Service is ditching .357 SIG for 9mm . 2 August 2019 .
  8. Web site: Real Guns - .357 SIG handloads...controlling headspace. November 17, 1999. https://web.archive.org/web/19991117202441/http://www.realguns.com/archives/001.htm. 1999-11-17.
  9. Web site: Tables of Dimensions of Cartridges and Chambers - Tab IV - Pistol and revolver cartridges. Note 6. . 2008-09-23. cip-bobp.org. C.I.P.. 2016-02-11. live. https://web.archive.org/web/20160304031347/http://www.cip-bobp.org/homologation/uploads/tdcc/tab-iv/tabivcal-en-page53.pdf. 2016-03-04.
  10. Web site: Real Guns - The return of the giant .357 SIG headspace Part I. December 7, 2000. https://web.archive.org/web/20001207022400/http://www.realguns.com/Commentary/comar25.htm. 2000-12-07.
  11. Book: . American National Standard Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Pistol and Revolver Ammunition for the Use of Commercial Manufacturers. New York, NY. American National Standards Institute.
  12. Web site: Accurate Powder . 2009-06-09 . .357 SIG . https://web.archive.org/web/20090327130930/http://www.accuratepowder.com/data/PerCaliber2Guide/Handgun/Standarddata/35738Cal(9.2mm)/357%20SIG%20pages%20103%20and%20104.pdf . dead . 2009-03-27.
  13. Marshall and Sanow, Stopping Power, Paladin 2001, p. 75.
  14. Web site: BBTI - Ballistics by the Inch :: .357 Sig Results. ballisticsbytheinch.com. 24 April 2018. live. https://web.archive.org/web/20171014200926/http://www.ballisticsbytheinch.com/357sig.html. 14 October 2017.
  15. Ayoob, Massad. (2002). The Gun Digest Book of Combat Handgunnery, 5th edition: Krause Publications.
  16. 0803.3051 . Scientific Evidence for Hydrostatic Shock . Michael Courtney . Amy Courtney . physics.med-ph . 2008.
  17. Sturtevant B, Shock Wave Effects in Biomechanics, Sadhana, 23: 579–596, 1998.
  18. 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.
  19. Gun Digest Buyer's Guide to Concealed-Carry Handguns By Jerry Ahern. 2010. p. 35.
  20. recorded results in Street Stoppers pg 173 .357 Magnum and Handgun Stopping Power by Marshall & Sanow
  21. physics/0701266 . Michael Courtney . Amy Courtney . Relative incapacitation contributions of pressure wave and wound channel in the Marshall and Sanow data set . 2007.
  22. Web site: BBTI - Ballistics by the Inch :: .357 Sig Results. www.ballisticsbytheinch.com.
  23. Web site: BBTI - Ballistics by the Inch :: .357 Mag Results. www.ballisticsbytheinch.com.
  24. Web site: BBTI - Ballistics by the Inch :: Scope of the Project. www.ballisticsbytheinch.com.
  25. Book: Marshall. Evan . Sanow . Edwin. Street Stoppers: The Latest Handgun Stopping Power Street Results. May 1, 1996. Paladin Press. 0873648722. 142.
  26. Web site: 38super.net Is For Sale. 38super.net. 24 April 2018. dead. https://web.archive.org/web/20120305063513/http://38super.net/Pages/Recoil.html. 5 March 2012.
  27. Web site: Auto-loader vs Revolver recoil.... thehighroad.org. 24 April 2018.
  28. Web site: MidwayUSA - Shop Shooting, Hunting, & Outdoor Products. MidwayUSA. 24 April 2018. live. https://web.archive.org/web/20180422051345/https://www.midwayusa.com/. 22 April 2018.
  29. Web site: .357 Sig|Shooting Illustrated . Wiley Clapp . Shooting Illustrated . 2011-03-09 . 2012-05-14 . dead . https://web.archive.org/web/20131102115535/http://www.shootingillustrated.com/index.php/6999/357-sig/ . 2013-11-02 .
  30. Web site: Texas Highway Patrol Dropping SIG Pistols in .357 SIG for S&W Pistols in 9mm. Dan. Cannon. 13 April 2014. gunssavelives.net. 24 April 2018. live. https://web.archive.org/web/20170823203808/http://gunssavelives.net/blog/texas-state-troopers-dropping-sig-pistols-in-357-sig-for-sw-pistols-in-9mm/. 23 August 2017.
  31. Web site: Texas DPS Ditches S&W M&P Handguns Over Reliability Issues - The Truth About Guns. 11 April 2014. thetruthaboutguns.com. 24 April 2018. dead. https://web.archive.org/web/20170711042546/http://www.thetruthaboutguns.com/2014/04/foghorn/texas-dps-ditches-sw-mp-handguns-reliability-issues-returns-sig-sauer/. 11 July 2017.
  32. Web site: DPS Suspends Use of New Handgun Over "Concerns". Terri . Langford . The Texas Tribune. 17 April 2014. myhighplains.com. 24 April 2018. live. https://web.archive.org/web/20150725074054/http://www.myhighplains.com/story/d/story/dps-suspends-use-of-new-handgun-over-concerns/19813/zwmkJGuhDkGJ8I5oPtMMvA. 25 July 2015.
  33. Web site: Sig Sauer P229: The handgun that protects the President—and you!. January 2013 . live. https://web.archive.org/web/20140810120215/http://www.personaldefenseworld.com/2013/01/sig-sauer-p229/. 2014-08-10.
  34. Web site: Texas Ranger Hall of Fame and Museum - Texas Rangers Today - Standard Issue Equipment. 2009. 29 May 2012. dead. https://web.archive.org/web/20120603160917/http://www.texasranger.org/today/Equipment.htm. 2012-06-03.