- It's a .357 Mag for Pistols Projects like cartridge development are always a team effort. In this case, SIG Sauer worked with Federal Premium Ammunition to develop the cartridge for release in 1994. The goal was to provide similar magazine capacity and dimensions of the popular .40 S&W, while replicating the ballistics of the revolver-only .357 Magnum.
- It's Reliable While the lower diameter and case rim dimensions are exactly the same between the .40 S&W and .357 Sig, the Sig round has a bottleneck profile to hold the smaller .355-inch diameter bullet. The case itself is also 0.009 inches longer. The bottleneck-shaped cartridges feed smoothly from magazines into the chamber, so .357 Sig guns have proven themselves to be extremely reliable. (Some folks make their own .357 Sig cartridge cases by reshaping .40 S&W brass. That will work, but isn't recommended because the cartridge will end up being slightly shorter than its official specification.)
- Highway Cops Like It A surprising number of state highway patrol agencies have adopted the .357 Sig caliber. If I had to guess as to the popularity in that specific community, I would surmise that highway patrol officers might be more likely to engage in road incidents requiring car door penetration. The extra velocity of the .357 Sig gives it better penetration performance over slower rounds such as the 9mm and .40 S&W.
- Not all Loads are Equal Some manufacturers choose not to provide the full performance capability of the cartridge. For example, Hornady loads its .357 Sig Critical Defense ammo with a lighter 115-grain bullet traveling at only 1,235 feet per second. Their 135-grain Critical Duty load moves at 1,225 fps. On the other hand, Mike McNett, the godfather of Doubletap Ammunition, loads his 125-grain cartridges to cook along at 1,525 feet per second. If you want to be all you can be when using a .357 Sig pistol, choose your ammunition carefully.
The P229 Was Tweaked for It As you might have guessed, the first handgun released for the cartridge came from the inventors. In 1994, SIG Sauer released a specially designed version of the popular P229 pistol to handle the higher pressures of the .357 Sig cartridge. Just in case you were wondering, the maximum pressures are either 40,000 pounds per square inch or 44,240 psi depending on whether you get your figures from Sporting Arms and Ammunition Manufacturers' Institute (SAAMI) or Commission Internationale Permanente pour l'Epreuve des Armes à Feu Portatives (C.I.P.).
It's Powerful Kinetic energy is one measurement of the "oomph" of any given cartridge. While you can't make generalizations that one bullet is twice as good as another if the kinetic energy is doubled, you can use the measure as a guideline. Many other factors like momentum, diameter, and bullet design come into play if you're trying to develop a picture of the overall destructive power of any given caliber and cartridge combination.