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.
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.