The Perfect Mix of Stopping Power, Reliability and Accuracy: Is the .357 SIG Law Enforcement’s Best Defense Cartridge?

By Suzanne Wiley published on in Ammunition

What an elusive round the .357 SIG is. Hardly talked about, never fodder for forum debate and difficult to find in stock. It has devoted followers and some of our most important law enforcement agencies—such as the Secret Service—depend on the .357 SIG. In fact, falling just under the .40 S&W, it is the second most issued caliber to law enforcement agencies nationwide.

Many experts—self-defense gun instructors and writers—along with many law enforcement professionals believe the .357 SIG has just the right combination of features to make it a near perfect self-defense round.

I do not have any real proof the following story actually happened, but when the Texas Department of Public Safety was switching from .45 ACP to the SIG Sauer P226 chambered for .357 SIG, officers were caught in a shoot out with some bad guys. A senior officer, still carrying his .45 ACP, fired into the cab of a tractor-trailer, but the bullet failed to penetrate the metal of the door. Another cop on the scene had his newly issued P226. He fired one round of .357 SIG into the tractor-trailer. It penetrated the steel and into the perpetrator’s head, killing him instantly. The one-shot stop myth might not be myth after all.

Picture shows a red box of American Eagle .357 SIG ammunition.

Essentially, but not exactly, the .357 SIG is a .40 S&W case, necked down for a 0.355” (9mm) bullet.

In the early 1990s, more and more law enforcement agencies were moving away from revolvers and moving toward semi-autos. Reluctant to leave their trusted .357 Magnum behind, Ted Rowe of SIG Sauer took on the task to develop a round that performed like the magnum, but fired from a semi-auto. In collaboration with Federal, the two came up with the .357 SIG. Essentially, but not exactly, the .357 SIG is a .40 S&W case, necked down for a 0.355” (9mm) bullet. (The .357 SIG case is longer than the .40 S&W case.)

Not often found in handgun cartridges, the .357 SIG has a bottleneck shape. Distinctive to rifle calibers, a bottleneck case is so deemed because it resembles a glass bottle. The neck is smaller than the bulk of the case. The distinction between the neck and the rest of the case forms a shoulder. The design allows a smaller bullet to travel as fast as a larger caliber bullet. The .357 SIG has the capability to reach velocities of 1500 fps! Not only is it a speedy little round, the bottleneck shape makes feeding issues virtually non-existent.

.357 SIG v. .357 Magnum

Before the .357 SIG’s introduction in 1994, no other round could match the .357 Magnum’s performance in a semi-automatic pistol. Rowe’s goal was to equal the performance of a 125-grain bullet shot from a 4-inch barrel .357 Magnum revolver out of a semi-automatic pistol. The benefits of Rowe and Federal’s round are plentiful. Among them are a higher capacity from an easier to conceal handgun with the same stopping power police officers depended on from the .357 Magnum. The .357 SIG has the capability to travel faster than the .357 Magnum with less recoil and muzzle flash. In some instances, it has shown to create a deeper wound as well

.357 SIG v. .40 S&W

Another giant plus to law enforcement was the fact that .357 SIG could penetrate barriers such as car metal, windshields and heavier clothing that the .40 S&W could not. The .357 SIG can also be loaded to higher pressures than the .40 S&W. Plus a full capacity magazine loaded with .357 SIG weighs less than a full mag of .40. Due to the similarities, .357 SIG guns can convert to .40 S&W with a barrel swap. Though its parent case is the .40 S&W, the dimensions are different. Therefore, you cannot use .40 S&W cases when reloading .357 SIG.


The .357 SIG shoots an extremely flat trajectory at longer ranges than its self-defense round counter parts. And gets even faster in longer, five or six-inch barrels. Massad Ayoob tested American Eagle’s 125-grain Full Metal Jacket bullet out to 25 yards in a 4-inch barrel Glock 32 Gen 4. He achieved highly satisfactory 1.05-inch groups. Push the .357 SIG even further, and accuracy is not compromised even out to 100 yards. Rumor has it the .357 SIG will over penetrate, but this just isn’t the case in reality. If so, the Federal Air Marshals would not be issued handguns chambered for .357 SIG. Not because a hole in the airplane would suck anyone out—it wouldn’t—but due to the confinement and closeness of people relative to the bad guy in a commercial airline cabin.

In tests, the .357 SIG outperformed the 9mm, .40 S&W and the .45 ACP in higher percentage success rates in one-shot stops, fatal shots, accuracy, and less number of rounds used to stop an assailant. Loaded to the same pressure as a .357 Magnum, but 14 percent higher than a .40 S&W or a 9mm, the .357 SIG creates quite the report when fired. Recoil is similar to the .40 S&W—if you need something to compare it to—but less than the .357 Magnum. It can handle a 160-grain bullet, but 125-grain jacketed hollow points perform best for self-defense. Its stopping power is undeniable.

The .357 SIG a niche caliber? Perhaps. However, it is certainly one that performs to a greater expectation for law enforcement than other self-defense rounds.

Do you own a .357 SIG? Tell us about it in the comment section.


Introduced to shooting at young age by her older brother, Suzanne Wiley took to the shooting sports and developed a deep love for it over the years. Today, she enjoys plinking with her S&W M&P 15-22, loves revolvers, the 1911, short-barreled AR-15s, and shooting full auto when she gets the chance. Suzanne specializes in writing for the female shooter, beginner shooter, and the modern-day prepper. Suzanne is a staff writer for Cheaper Than Dirt!

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Comments (54)

  • Bob Clevenger


    Wow! Does this thread have a life of its own or what?
    Re-reading the original article I am struck by the impression that the author seems to think that there are only four suitable semi-auto cartridges for Self Defense use: the 9mm Parabellum, the .357 Sig, the .40 S&W, and the .45 ACP. While these are all good choices for SD use I think there are more (and arguably better) choices that can be made.
    What about the 10mm?
    What about the 9×23 Winchester?
    And what about the .38 Super which actually predated the .357 Magnum?
    And just for grins, what about the 7.62×25 Tokarev (or 7.63 Mauser), the .22 TCM, and the 5.7 FN?

    All the above have more power than a 9×19 Parabellum, all are chambered in semi-auto pistols and all — save the 10mm — have the same ammo capacity as the 9×19 — which is more than the .357 Sig.
    I will freely admit that good SD ammo for the 7,62 Tokarev is difficult to find, but load up some 90 gr. .308 Hornady XTP bullets and give it a try.

    Essentially I am trying to say that as long as we just keep comparing the same old “popular” rounds to each other we are not learning anything.

    Where’s Elmer Keith when you need him?


  • Derrick


    Not with expanding ammo


  • Derrick


    I picked up a SIG P229R cpo in .357sig a few years ago and feel in love with the cartridge. To make things even better I got a 9mm conversion barrel for when moneys tight. Now if only I could get a .357sig barrel for my Kahr TP40 that would be my ideal carry piece.


  • John MadDog Kicinski


    The .357 sig is all that is good in a single caliber. I bought a Glock 31 gen 3 in .357 sig really loved it, but ammunition at that time was extremely prohibitively expensive. I’ve got to tell you it was one of the most accurate handguns that I’ve owned period. Unfortunately I sold it and bought another handgun. Well now five years later I’ve bought myself a new Glock 31gen 4 in .357 sig which truth be told is even better as it comes with three x-tea magazines and hand grip modifiers, so you can change your grip size on your handgun, I really like this feature as I have it on my smith & Weston m&p .40 cal it also has grip extensions. So as much as I regretted getting rid of my first Glock, my second Glock is that much more sweeter 😎


  • stephen milata


    I’m thinking of buying the Glock G27 gen4. as a sub-compact for concealed carry. It can shoot 357 Sig, 40 Cal and 9MM with just a barrel and magazine change. Anybody think that’s a good idea too?


    • Dave Dolbee


      I have the G23 and G22 with 9mm and .357 SIG barrels for each—I love it! ~Dave Dolbee


  • Jeff Ullrich


    I own a S&W M&P in 357 sig and my brother has a Sig Sauer P320 in 357 sig. This caliber is amazing. It’s accurate, very manageable recoil and has awesome stopping power and penetration.


  • Bill Hunt


    Do I need to worry about anything behind the target?

    “He fired one round of .357 SIG into the tractor-trailer. It penetrated the steel and into the perpetrator’s head, killing him instantly”.


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