Why consider a 357SIG Caliber
Why 9mm Bullets Get No Respect

(see the 357SIG Information Site for more information on 357SIG ammunition)
By Peter Jordan, petej88@hotmail.com

Dick Metcalf states: "The 357 Sig is the best 9mm cartridge made. It shoots like a 357 Magnum, recoils like a 9mm Luger, operates more reliably than a 40 S&W, requires no significant new engineering or tool-up costs to produce, and there are already eight high-performance, new-tech, premium-brand commercial ammo loads on the market (not to mention all the handloading tools and components...)."

Let's see why this new cartridge continues to gain converts. Discounting wildcat cartridges, the 357 Sig is the first bottlenecked handgun cartridge to hit the mainstream in over 75 years. The following paragraphs discuss a number of reasons for the above quote:

1. A 3.86" barrel can push a standard 124/125 grain 357 Sig bullet between 1306 and 1418 fps. A 4.5" or longer barrel can push a bullet to 1450 fps and beyond, putting it into the IPSC Major Category for the sports minded. Yet, the compact 357 Sig cartridge can easily fit into small to medium size combat/defense pistols.

On the other hand, the 9x23mm Winchester cartridge also easily makes IPSC Major. But, because of its long cartridge length, it is by necessity used in large framed pistols to house it. So while the 9x23mm Winchester is an excellent sport cartridge, it lacks the versatility of the 357 Sig --- See Attachment 4.


For those interested in a semiauto that is generally comparable to a 4" 357 Magnum revolver, but has faster follow up shot capability, the 357 Sig fits the bill. The 357 Sig has a softer perceived recoil than a 357 Magnum revolver of equal size and weight. Although the SAAMI specs from a 357 Magnum test barrel is 1450 fps, a typical 4" 357 Magnum often generates about 1350 fps, which happens to be the same velocity as the 357 Sig caliber from a 4" barrel --- See Attachment 6.

3. Typical 357 Sig bullets have a diameter of .355 as opposed to the 357 Magnum with its .357 bullets. If other cartridges can be marketed in such a way that a .36 caliber bullet is loaded into a 38 Special cartridge, etc, then a 9mm (.355) bullet has just as much right to be used in a 357 Sig cartridge.
4. Perceived recoil of the 357 Sig varies a great deal, depending on whom you talk to. To me, the 125 grain 357 Sig round feels similar to shooting a Corbon 135 grain .40 S&W round. Ed Sanow states, "Given pistols of the same weight, action and ergonomics, the felt recoil of the .357 SIG 125-grain JHP is LESS than the .40 S&W 155, COMPARABLE to the .40 S&W 180-grain loads and MORE than the 9mm 115- and 124- grain +P+ and 147-grain loads".
5. Given the pressure levels and slide velocities of the 40 S&W and the 357 Sig, you can use the same recoil spring. In fact, the 357 Sig may even improve the functional reliability of your 40 S&W pistol.
6. You get even more feeding reliability *insurance* using a bottlenecked cartridge --- ramming a 9mm bullet into a 40 S&W chamber opening. "Straight wall" fans may scoff at this; but the facts are the facts. The 357 Sig is a Superior feeding auto pistol cartridge period.

Glock engineers actually took advantage of this bottlenecked cartridge when they engineered their new .357 Glocks. As a result, these new 357 Sig barrels have a fairly tight chamber as well as a fully supported chamber in the 6 o'clock position.

You get one other advantage with the bottlenecked 357 Sig cartridge, which it shares with its bigger brother for large framed pistols, the 400 Corbon. The velocity spreads can often be less than 20 fps, which is quite excellent. (If you are interested in more information on the 400 Corbon, contact Cor-Bon (605-347-4544) or read the following web pages: rec.guns and/or www.glockmeister.com).

Accurate Arms Company stated, "This is without a doubt the most ballistically consistent handgun cartridge we have ever worked with. The standard deviation for every single load developed was less than 10 fps. The average SD was 5 fps. This is impressive for any cartridge but especially so for a handgun. The small bottleneck and high working pressure of the round must both contribute to this amazing consistency..."

7. The 357 Sig conversion kit is simply a drop-in barrel replacement in the fabulous 40's. The 357 Sig and 40 S&W can easily co-exist and be used interchangeably based on application needs.
8. Several ammo companies are now supporting the 357 Sig, with the lower priced factory practice rounds from Remington and CCI/Speer Lawman labels to the more exotic 2200+ fps cartridges --- See Attachment 3.
9. The 357 Sig is really cheap to reload and shoot, ($4.00/box), because of using the universal 9mm bullet. (Rainier plated 9mm 124 gr FP, $43/1000). Rainier bullets use an electro-plating process that produces a molecular bond between the copper and lead.
10. For the generations of American shooters who have never seen or fired a bottlenecked handgun cartridge before, here are the only extra reloading steps needed for a "straight waller". Just like bottlenecked rifle cartridges, you lube the brass before resizing and dry it after crimping, as well as check the case length to make sure it stays within trim specs after firing. My 357 Sig reloads have never needed trimming. The 9mm bullet must also have a short nose to seat properly, with a preferable diameter of .355, to assure a tight non-slipping bullet crimp; Don't deform the bullet during the crimping process. Safety means passing the thumb pressure test --- See Attachment 5.
11. You can now get a 'standard' +P+ 9mm-like semiauto (the 357 Sig) that is within SAAMI specs, unlike the standard 9mm pistol. This can be an important point when agencies make pistol bids, and to standardize on the only REAL level of effective 9mm bullet 'velocity' that scores in the over 90% one-shot-stop category. Put another way, the 357 Sig is the best 9mm Magnum duty cartridge available --- See Attachment 3.
12. The strong brass was constructed to handle a standard 40,000 psi, as opposed to the 35,000 psi SAAMI spec for the 9mm and 40 S&W.
13. The 357 Sig has the option of pushing heavier bullets like the 147/150 grainers, to higher velocities than a standard 9mm pistol is able to do (1127-1218 fps from a standard 4" barrel) --- See Attachment 3.
14. The 357 Sig and 40 S&W 135 grain rounds both produce over 500 ft/lbs of energy. But the 357 Sig is clearly ahead if you have application needs using lighter bullets that penetrate well --- See Attachments 1 & 2.
15. The 357 Sig has the energy and trajectory of a lighter weight 40 S&W bullet, yet the 357 Sig penetrates like a 180 grain 40 S&W bullet. Once again, you get two for the price of one. Ed Sanow stated, "The Glock 31 firing .357 SIG 125-grain JHPs has about the same felt recoil as a Glock 22 firing .40 S&W 180-grain JHPs. With 50 percent more energy, the .357 SIG has better tactical penetration." --- See Attachments 2, 3,& 4.
16. Tests by a number of gun writers have shown that the 357 Sig is inherently accurate --- See Attachments 3 & 6.
17. Besides the AMT DAO Back up, KBI's 1911, Laseraims's Velocity, and Sig's P226, P239, and P229, Glock also began manufacturing 357 Sig pistols in early '98 (M31, M32, and M33). As a result, I'm guessing that other large firearms companies such as S&W may join the pack too. Incidentally, Sig-Saur and Federal worked together to design and introduce the 357 Sig in the summer of '94.
18. A number of Agencies are now using the 357 Sig.
19. The 357 Sig caliber is recognized in the new IDPA (International Defensive Pistol Association), which has an edge on 'practical' defense shooting with stock duty/defense guns. The IDPA also uses a more realistic power factor rating for duty cartridges. Unfortunately, the IPSC/USPSA (United States Practical Shooting Association) still uses the 'obsolete' major power factor of 175 along with a different, biased point standard for those that shoot in the major category.
20. Many people haven't even begun to tap into the versatility and capability of the new 357 semiauto (The 357 Sig) --- See Attachment 7.
In summary, quoting from Handguns, April 1996:

"However, for the shooter who wants it all (high energy, flat trajectory, high velocity, extreme accuracy, high firepower and deep penetration) in a single cartridge that fits in a concealable, shootable handgun, the 357 Sig is just the ticket."

Here is a comparison of Ed Sanow's penetration data comparing the Federal 357 Sig standard round with the Corbon 40 S&W 135 grain round:
Cartridge Penetration Expansion Crush
357 Sig Federal 125 gr JHP 13.7 .59 3.7 43.4
40 S&W Corbon 135 gr JHP 9.8 .56 2.4 69.1

Note: The 357 Sig Federal bullet is engineered to not fragment, while the 40 S&W Corbon 135 gr bullet violently expands and fragments.

A number of agencies are buying the 357 Sig for the express purpose of penetrating through car bodies, glass, etc in order to get the job done. A Corbon 135 grain 40 S&W could not do this kind of work; but it's excellent for an open head-on confrontation.

I'm not saying that you can't tune a light weight 40 S&W round to excel in the 357 Sig's domain. But I don't buy the argument that a 357 Sig isn't needed because the 40 S&W 135 grain cartridge 'exists'; this argument is for people that are too lazy to switch barrels (just kidding).

Here is a chart based on a FBI test comparing the standard 357 Sig 125 grain Federal load with a 155 grain Hornady XTP 40 S&W load. It's interesting that the chart is based on a 3.86" Sig 229 barrel and a Glock 22 4.49" barrel, which gives substantial velocity advantage to the Glock. The velocity increase from a 4" to a 4.5" 357 Sig barrel is dramatic. I'm guessing that a Glock 357 Sig Carbine would be a real smoker.

FBI Eight Step Test Results: (Penetration in inches)

(357 Sig barrel: 3.86"; 40 S&W barrel: 4.49")

Cartridge 1 2 3 4 5 6 7 8
357 Sig 125 gr Federal 14.0 20.1 22.9 17.1 19.5 13.8 20.5 12.1
40S&W 155gr Hornady XTP 14.5 18.1 23.0 14.0 18.3 10.7 15.9 12.1
115gr 9mm Win Silvertip 10.0 11.8 12.7 12.9 13.1 9.2 10.5 10.5

[editor's note: for more info on the FBI test series, see FBI Ballistic Protocol page at this site)

Here is a non-exclusive chart showing several 357 Sig Factory Rounds that provide excellence in penetration, accuracy, and high energy:

(based on a 3.86" 357 Sig 229 barrel)

This chart doesn't even take into consideration 4.5" to 5" 357 Sig barrels that are available now.

Cartridge Penetration Velocity Energy 25m Accuracy
Magsafe 64 gr defender 11.3 2230 707
Corbon 115 gr Sierra jhp 12.5 1450 537
Federal 125 gr jhp 13.7 1418 548 2.13
Corbon 124 gr Bonded HP 16.5 1400 540
Federal 125 gr FMJ 17.5 1394 536 2.25
CCI-Speer 125 gr Gold Dot 14.5 1374 520 2.00
Speer 125 gr TMJ 17.0 1355 505 2.13
Remington 125 gr jhp 14.0 1339 485 2.38
Hornady 124 gr XTP 13.5 1306 460 1.88
Hornady 147 gr XTP 13.7 1218 480 2.13
Federal 150 gr jhp 13.25 1127 422 2.50

As you can see, the 357 Sig doesn't base penetration on just one cartridge brand. And there are some 357 Sig rounds that have mild penetration characteristics and others that have slower, quieter, transonic velocities. As the 357 Sig catches on, I'm sure there will be more cartridges coming out to fill the various niches.

Here is a Comparison of 7 different 9mm cartridge types along with the .357 Magnum cartridge (in order of Wound Area):
Cartridge Velocity Wound Area (sq in) Firearm Barrel Length
357 Sig/Speer 125 gr Gold Dot 1374 25.95 SIG P229 3.86
357 Magnum/Winchester 125 gr jhp 1375 23.66 S&W M66 4.00
9x23mm CP/Elite Ammo 124 gr hp/xtp 1326 22.98 Colt 1991 5.00
356 TSW/Federal 135 gr Hydra-Shok 1199 22.47 S&W M3566 5.00
9mm Luger/Federal 135gr Hydra-Shok 1037 21.81 Glock M26 3.50
9x23mm Win/Win. 125 gr Silvertip 1463 21.07 Colt 1991 5.00
9x23mm Largo/Speer 124 gr Gold Dot 1197 20.51 Colt 1991 5.00
38 Super/Remington 115 gr jhp 1303 19.41 Colt 1991 5.00

Note: As I mentioned above, a longer barrel than the standard 3.86" barrel length significantly increases the 357 Sig velocity. Some people have recorded increases to over 1450 fps in longer barreled pistols.

Here's some Reloading Information

SAFETY DISCLAIMER --- Read this before looking at the following reloading section: Use this information at your own risk. It's much safer to use official Reloading Manuals and start with mild powder charges. This data is provided to simply give you some ideas about available reloading information, as well as show some powder types and charges that can be used for the 357 Sig. Under-charges can be just as dangerous as over-charges.

Non-exclusive list for 357 Sig reloading data:

Speer/Blount 208-746-2351

Accurate Arms Company 800-416-3006

Hodgdon (www.hodgdon.com)

Vihtavouri (www.vihtavuori.fi); data in their Free Reloading Manual

Alliant (reloading.atk.com)

Sierra 50th Edition Reloading Manual

Various third party sources like Charles Petty using Winchester WAP, etc.

Dillon Blue Press (800-223-4570) makes an excellent carbide die set for the 357 Sig.

Midway (800-243-3220) sells several brands of 357 Sig die sets.

Several barrel companies support the 357 Sig caliber:

Jarvis 406-961-4392

Bar-Sto 619-367-2747

Olympic Arms

I've been told that Advanced Tactical Firearms (new name for Accu-Match) is tooling up to support the 357 Sig.

357 Sig cartridge:

Max over-all-length (oal): 1.140

Factory oal generally ranges around 1.135

Mouth: .381

Nominal bullet size: .355

40,000 psi --- maximum average pressure.

Small primer.

Headspaces on the case mouth, not the shoulder. Headspace is easier to control if it is based on overall length rather than midway up the shoulder.

Max case length: .865

Trim-to length: .855

Check the length of the case to make sure it is less than the maximum allowable case length dimension, especially when using full power loads. I've also noticed that the Federal nickel plated cases have a tendency to stretch more, which would bring trimming and chamfering into play. Starline brass seems to hold its dimensions pretty well.

Don't resize 10mm brass or 40 S&W brass into 357 Sig brass. There is an abundant brass supply from Starline (800-280-6660) and from ammo companies. The 10mm has different internal construction along with large primers; As a result, the combination could be quite dangerous.

Another good reason to use real 357 Sig brass is because the case wall is a little thicker than .40 S&W brass, and it will help hold the bullet in place. The internal 357 Sig case dimensions are also more beefed up than the .40 S&W case.

Cleaning Note: With the new .357 bottlenecked cartridge, you must be very careful to actually clean the INITIAL *wide part* of the chamber. One way to do it, is to use a .40 caliber bore brush to clean ONLY the wide part of the chamber. Then, use the 9mm bore brush to clean the rest. Just don't get carried away and ram the .40 caliber brush all the way through the bore!

Wiley Clapp states (from a SigArms Brochure):

"The .357 SIG cartridge is a police service or combat/defensive load intended to bring .357 Magnum performance to a high-capacity semiauto pistol.

"As long as you compare 125-grain .357 SIG loads with 125-grain .357 Magnums and keep the barrel lengths roughly comparable, the velocities will be the same, and in fact often favor the .357 SIG. Winchester's [Magnum] 125-grain JHP did not exceed the velocity of the .357 SIG until I went to a full six inches of barrel. Some of the time, 125-grain .357 Magnum JHP's will edge the new Sig round in four inch barrels, but not overwhelmingly so.

"I checked the accuracy of the new cartridge in the P229 by shooting 10-shot groups with the pistol mounted in the Ransom Rest and the targets placed at 25 yards. Four different lots of ammunition were used, including both old and new lots of the federal 125-grain JHP load, a single lot of the Federal 125-grain FMJ load, and one experimental lot of the Speer 125-grain Gold Dots. Accuracy is just plain outstanding. Twelve 10-shot groups, three with each lot of ammunition, averaged 1.99 inches. The best was 1.59 inches, but any gun and cartridge that will do two inches at 25 yards is just fine with me. And by the way, the hands-on shootability of the gun and ammo is excellent --- far better than that of a comparable revolver."

It's really a moot point to state that the 357 Sig would never have survived if it were not a simple drop-in barrel replacement for 40 S&W pistols, since it can never be proven. Dido for the argument that the 357 Sig is just another money making scheme. And if you must, by all means go ahead and complain about various gun magazine writers if that makes you feel better. Finally, if you're really desperate, go ahead and say the 357 Sig is yet another new version of the old 9mm --- a solution to a non-problem.

But! Let's just look at the 357 Sig facts. To ignore the 357 Sig is to miss the point. A typical compact, 'easy to control' 357 Sig provides excellent, 'standard high velocity', 9mm-magnum-performance and it provides 'superior' feeding in semi-auto defense/sport pistols. The 9mm bullet in this new incarnation deserves a lot of Respect.

The Feb '96 issue of Handguns has a comparison article on the 357 Sig, 40 S&W, 10mm, and the 45acp. Conclusions: "There isn't a lot of difference between popular defensive calibers. Human variables are much more likely to matter than minor differences in recoil and theoretical controllability. Case in point: Jan did his fastest shooting with the 45 auto. Dave Arnold did his slowest. Both Jan and Dave were very impressed by the 357 Sig cartridge. Even though it generated the second highest muzzle energy, [357 Sig: 536 ft/lbs; 10mm: 584 ft/lbs], of the four [guns] we tried, it seemed easily the most pleasant to shoot, and both of us shot it fast and well. We think this cartridge may well be a real 'comer'. Given the inherent feed reliability of its bottlenecked case shape, it may well prove to be the best cartridge of all for combat auto pistols."

Walt Rauch stated in his .357 Glock article, from Autopistols Magazine, "The new .357 cartridge successfully duplicated the performance of the highly touted 125-grain .357 Magnum revolver load in a mid-framed autopistol."

Jan Libourel, reporting on the 357 Sig from Guns & Ammo, stated,"I don't think there's a sidearm/cartridge combination in the world that offers a better level of protection."

In "Handguns", Ed Sanow stated, "The .357 SIG is here to stay."

Acknowledgements I would like to acknowledge the following sources for providing 357 Sig information, especially for the information in the above charts:

"Glock's New .357s!" by Walt Rauch, Glock Autopistols, 1998 Vol. 4 No. 1.

Ed Sanow's 357 Sig article in March '98 Handguns.

"357 Sig: Powerful, Reliable And Going Strong" by Dick Metcalf, Shooting Times, Nov 1997.

"'HOT NINE' Cartridge Showdown: An All-Out Test To Name The Best!" by Dick Metcalf, Hand Gunning, Nov/Dec 1997.

"The 357 Sig: How Good Is It?" by Ed Sanow, Handguns, Jan 1996.

"FBI Tests the 357 Sig" by Dr Martin Topper, Handguns, April 1996.

"Critical Analysis: Inside the .357 SIG" by Charles Petty, Guns, June '96.

Unofficial Sig Home Page on the Web.

Official SigArms Brochure with a 357 Sig article by Wiley Clapp.

Glock-l USENET Email Group who have provided stimulating critiques.


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