.357 SIG
.357 SIG jacketed flat point cartridge
Place of originSwitzerland
United States
Production history
DesignerSIGARMS / Federal Premium Ammunition
Parent case10mm Auto
Case typeRimless, bottleneck
Bullet diameter9.02 mm (0.355 in)
Land diameter8.71 mm (0.343 in)
Neck diameter9.68 mm (0.381 in)
Shoulder diameter10.77 mm (0.424 in)
Base diameter10.77 mm (0.424 in)
Rim diameter10.77 mm (0.424 in)
Rim thickness1.40 mm (0.055 in)
Case length21.97 mm (0.865 in)
Overall length28.96 mm (1.140 in)
Case capacity1.27 cm3 (19.6 gr H2O)
Rifling twist406 mm (1 in 16 in)
Primer typeSmall pistol
Maximum pressure (C.I.P.)305.0 MPa (44,240 psi)
Maximum pressure (SAAMI)275.8 MPa (40,000 psi)
Ballistic performance
Bullet mass/type Velocity Energy
8.1 g (125 gr) Federal FMJ 1,350 ft/s (410 m/s) 506 ft⋅lbf (686 J)
8.1 g (125 gr) Doubletap FMJ-FP 1,450 ft/s (440 m/s) 583 ft⋅lbf (790 J)
5.83 g (90 gr) Grizzly JHP 1,900 ft/s (580 m/s) 721 ft⋅lbf (978 J)
8.1 g (125 gr) Underwood TMJ 1,475 ft/s (450 m/s) 604 ft⋅lbf (819 J)
6.48 g (100 gr) Cor-bon PB 1,600 ft/s (490 m/s) 568 ft⋅lbf (770 J)
Source(s): 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.[1]

The .357 SIG (designated as the 357 Sig by the SAAMI[2] and 357 SIG by the C.I.P.[1] or 9×22mm in unofficial metric notation) is a bottlenecked rimless centerfire 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]


The .357 SIG is based on a necked-down 10mm Auto case. Other than specialized competition cartridges like the 9×25mm Dillon (1988), which necked a 10mm Auto case down to a 9 mm bullet, the .357 SIG (1994) was the first modern bottleneck commercial handgun cartridge since the early 1960s, when Winchester introduced a .257 caliber round based on the .357 Magnum, the now obsolete .256 Winchester Magnum (1960). Then 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), a shortened version of their .222 Remington.

Due to its expense, as .357 SIG practice ammo is about twice the cost of 9mm and around 50% more than .40 S&W, .357 SIG never achieved widespread adoption like .40 S&W.[4][5][6]

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.

Several sources have published contradicting information regarding .357 SIG headspacing.[7] This is due to the cartridge having been originally designed as a .357 (9.02mm) round, but then rapidly adapted to the .355 (9mm) 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).[8] Some US sources are in conflict with this standard.[9] However, the cartridge and chamber drawing in the ANSI/SAAMI American National Standards also clearly shows the cartridge headspacing on the case mouth.[10] 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.[11]


Left to right: .357 SIG, 10mm Auto, .40 S&W

While it is based on a 10 mm case necked down to accept 0.355-inch (9.0 mm) bullets, the .357 SIG cartridge case is slightly longer than .40 S&W by 0.009 in (0.23 mm) to 0.020 in (0.51 mm) 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.


The table below shows common performance parameters for several .357 SIG loads. Bullet weights ranging from 115 to 150 grains (7.5 to 9.7 g) have been offered. Loads are available with energies from 488 foot-pounds force (662 J) to 583 foot-pounds force (790 J), and penetration depths from 9 inches (230 mm) to over 16.5 inches (420 mm) are available for various applications and risk assessments. Note: Underwood now also offers a standard pressure 65 gr .357 SIG Xtreme Defender (XD) round with a muzzle velocity of 2100 fps, muzzle energy of 636 ft. lbs. and a penetration depth of 17.5 inches.

Manufacturer Load Mass Velocity Energy Expansion[12] Penetration[12] PC[12] TSC[12]
Triton Quik-Shok 115 gr (7.5 g) 1,425 ft/s (434.3 m/s) 518 ft⋅lbf (702.3 J) frag 9.0 in (228.6 mm) 4.1 cu in (67.2 cm3) 43.2 cu in (707.9 cm3) (est)
Winchester Ranger T 125 gr (8.1 g) 1,385 ft/s (422.1 m/s) 532 ft⋅lbf (721.3 J) 0.75 in (19.1 mm) 11.5 in (292.1 mm) 5.1 cu in (83.6 cm3) 45.0 cu in (737.4 cm3) (est)
Federal Premium JHP 125 gr (8.1 g) 1,430 ft/s (435.9 m/s) 568 ft⋅lbf (770.1 J) 0.62 in (15.7 mm) 12.7 in (322.6 mm) 3.8 cu in (62.3 cm3) 49.5 cu in (811.2 cm3) (est)
Speer Gold Dot JHP 125 gr (8.1 g) 1,385 ft/s (422.1 m/s) 532 ft⋅lbf (721.3 J) 0.68 in (17.3 mm) 16.5 in (419.1 mm) 6.0 cu in (98.3 cm3) 45.0 cu in (737.4 cm3) (est)
Remington JHP 125 gr (8.1 g) 1,350 ft/s (411.5 m/s) 506 ft⋅lbf (686.0 J) 0.57 in (14.5 mm) 14.3 in (363.2 mm) 3.6 cu in (59.0 cm3) 41.7 cu in (683.3 cm3) (est)
Federal Premium JHP 150 gr (9.7 g) 1,210 ft/s (368.8 m/s) 488 ft⋅lbf (661.6 J) 0.60 in (15.2 mm) 15.0 in (381.0 mm) 4.2 cu in (68.8 cm3) 39.4 cu in (645.7 cm3) (est)
Underwood Gold Dot JHP 125 gr (8.1 g) 1,450 ft/s (442.0 m/s) 583 ft⋅lbf (790.4 J) 0.75 in (19.1 mm) 16.5 in (419.1 mm) 6.0 cu in (98.3 cm3) 45.0 cu in (737.4 cm3) (est)

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[13] 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 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.

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.[14] 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.[15][16][17] 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.[18]

The "Accurate Powder" reloading manual claims that it is "without a doubt the most ballistically consistent handgun cartridge we have ever worked with."[11]


From left to right: 9mm, 7.62×25mm Tokarev, .357 SIG, 10mm Auto, .40 S&W, .45 GAP, .50 AE.

The goal of the .357 SIG project was to offer a level of performance equal to the highly effective 125-grain (8.1 g) .357 Magnum load.[19][20] Measurements of standard factory .357 SIG cartridges loaded with 125-grain (8.1 g) bullets showed approximate muzzle velocities of 1,450 feet per second (440 m/s) out of a 4 inches (102 mm) barrel, which is essentially identical to the .357 Magnum with the same bullet weight and barrel length.[21][22] 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.[23]

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,[24] 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.[25] A more accurate view on recoil is that it is proportional to the mass of all ejecta × velocity of ejecta.[26]

In comparing the energy levels of premium self-defense ammunition, the muzzle energy of 584 ft⋅lbf (792 J) of the 125 grains (8.1 g) 1,450 feet per second (440 m/s) .357 SIG load is greater 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.[27]


Oblique view of a .357 SIG FMJ cartridge.

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.[28]

However, in 2013 the Texas DPS decided to replace their .357 SIG handguns with 9mm handguns.[29] The ability to carry more rounds per magazine (9mm vs. .357 SIG) in a lighter gun were among the stated reasons for the change.[30] That transition was suspended after recruits in the A-2014 class, the first to train with the new S&W M&P 9mm polymer handguns, experienced numerous malfunctions with those weapons.[31]

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


  1. ^ a b c "C.I.P. TDCC datasheet 357 SIG" (PDF). cip-bobp.org. Archived (PDF) from the original on 4 August 2016. Retrieved 24 April 2018.
  2. ^ "SAAMI 357 Sig cartridge and chamber drawings" (PDF). saami.org. Archived from the original (PDF) on 2014-07-14. Retrieved 24 April 2018.
  3. ^ a b c d e The Gun Digest Book of Sig-Sauer: a complete look at Sig-Sauer pistols. Massad Ayoob. 2004. pp. 51–53.
  4. ^ "Ammo Showdown: .357 Sig vs .40S&W". JM4 Tactical.
  5. ^ ".357 Sig: What's the Point of this Cartridge?". 23 August 2018.
  6. ^ "Why .357 Sig Never Caught on". 28 March 2014.
  7. ^ "Real Guns - .357 SIG handloads...controlling headspace". November 17, 1999. Archived from the original on 1999-11-17.
  8. ^ "Tables of Dimensions of Cartridges and Chambers - Tab IV - Pistol and revolver cartridges" (PDF). cip-bobp.org. C.I.P. 2008-09-23. p. Note 6. Archived (PDF) from the original on 2016-03-04. Retrieved 2016-02-11.
  9. ^ "Real Guns - The return of the giant .357 SIG headspace Part I". December 7, 2000. Archived from the original on 2000-12-07.
  10. ^ American National Standard Voluntary Industry Performance Standards for Pressure and Velocity of Centerfire Pistol and Revolver Ammunition for the Use of Commercial Manufacturers (PDF). New York, NY: American National Standards Institute.
  11. ^ a b ".357 SIG" (PDF). Accurate Powder. Archived from the original (PDF) on 2009-03-27. Retrieved 2009-06-09.
  12. ^ a b c d Marshall and Sanow, Stopping Power, Paladin 2001, p. 75.
  13. ^ "BBTI - Ballistics by the Inch :: .357 Sig Results". ballisticsbytheinch.com. Archived from the original on 14 October 2017. Retrieved 24 April 2018.
  14. ^ Ayoob, Massad. (2002). The Gun Digest Book of Combat Handgunnery, 5th edition: Krause Publications. ISBN 0-87349-485-7
  15. ^ Michael Courtney; Amy Courtney (2008). "Scientific Evidence for Hydrostatic Shock". arXiv:0803.3051 [physics.med-ph].
  16. ^ Sturtevant B, Shock Wave Effects in Biomechanics, Sadhana, 23: 579–596, 1998.
  17. ^ 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.
  18. ^ Gun Digest Buyer's Guide to Concealed-Carry Handguns By Jerry Ahern. 2010. p. 35.
  19. ^ recorded results in Street Stoppers pg 173 .357 Magnum and Handgun Stopping Power by Marshall & Sanow
  20. ^ Michael Courtney; Amy Courtney (2007). "Relative incapacitation contributions of pressure wave and wound channel in the Marshall and Sanow data set". arXiv:physics/0701266.
  21. ^ "BBTI - Ballistics by the Inch :: .357 Sig Results". www.ballisticsbytheinch.com.
  22. ^ "BBTI - Ballistics by the Inch :: .357 Mag Results". www.ballisticsbytheinch.com.
  23. ^ "BBTI - Ballistics by the Inch :: Scope of the Project". www.ballisticsbytheinch.com.
  24. ^ Marshall, Evan; Sanow, Edwin (May 1, 1996). Street Stoppers: The Latest Handgun Stopping Power Street Results. Paladin Press. p. 142. ISBN 0873648722.
  25. ^ "38super.net Is For Sale". 38super.net. Archived from the original on 5 March 2012. Retrieved 24 April 2018.
  26. ^ "Auto-loader vs Revolver recoil..." thehighroad.org. Retrieved 24 April 2018.
  27. ^ "MidwayUSA - Shop Shooting, Hunting, & Outdoor Products". MidwayUSA. Archived from the original on 22 April 2018. Retrieved 24 April 2018.
  28. ^ Wiley Clapp (2011-03-09). ".357 Sig|Shooting Illustrated". Shooting Illustrated. Archived from the original on 2013-11-02. Retrieved 2012-05-14.
  29. ^ Cannon, Dan (13 April 2014). "Texas Highway Patrol Dropping SIG Pistols in .357 SIG for S&W Pistols in 9mm". gunssavelives.net. Archived from the original on 23 August 2017. Retrieved 24 April 2018.
  30. ^ "Texas DPS Ditches S&W M&P Handguns Over Reliability Issues - The Truth About Guns". thetruthaboutguns.com. 11 April 2014. Archived from the original on 11 July 2017. Retrieved 24 April 2018.
  31. ^ Tribune, Terri Langford, The Texas (17 April 2014). "DPS Suspends Use of New Handgun Over "Concerns"". myhighplains.com. Archived from the original on 25 July 2015. Retrieved 24 April 2018.((cite web)): CS1 maint: multiple names: authors list (link)
  32. ^ "Sig Sauer P229: The handgun that protects the President—and you!". January 2013. Archived from the original on 2014-08-10.
  33. ^ "Texas Ranger Hall of Fame and Museum - Texas Rangers Today - Standard Issue Equipment". 2009. Archived from the original on 2012-06-03. Retrieved 29 May 2012.