gun for 357 sig ammo

There Are Still .357 Sig Pistols Out There...Just Fewer Of Them These Days

One cartridge that seems to have not gotten the love that it seems to deserve - on paper at least - is the .357 Sig cartridge. It's kind of too bad that it hasn't, because it has all the hallmarks of a great defensive round and the service pedigree to go with it.


However, it hasn't quite caught on the way it perhaps should have. It might not exactly be a .357 Magnum but it comes as close as many autoloading rounds get. It's also still fairly available, if you know where to look.


The .357 Sig - For When 9mm Just Isn't Good Enough


357 sig vs 9mm

The reason why the .357 Sig exists is to duplicate the performance of certain .357 Magnum loads in a cartridge that can be fired by an autoloading pistol. The issue heretofore is that .357 Mag is a big cartridge with a lot of chamber pressure; manufacturing an autoloader that can handle both is not easy, nor cheap.


For the moment, there are only two autos that chamber the .357 Mag - the Magnum Research Desert Eagle and Coonan, Inc. pistols. Both are large (though Coonan makes a compact model...which is the size of a GI 1911) and very expensive.


Anyway, Sig Sauer decided they would take a crack at it and created the round by shortening a 10mm Auto case and bottlenecking it down to take a .355-in diameter projectile. Then they stuffed it with enough propellant to send a 125-grain projectile screaming downrange at more than 1400 feet per second. In other words, they duplicated the performance of a 125-gr .357 Magnum cartridge fired from a 4-inch barrel, a common configuration for police revolvers and home defense guns.


The .357 Sig also happens to carry more energy than defensive rounds in it's same class, topping the .40 S&W and certainly the 9mm, so it hits with more force. It can also accept a larger bullet than 9mm, as the biggest projectiles for the Sig top out at about 160 grains, whereas 147 grains is about as large as a 9mm bullet can get.


That's what made it an instant success in the law enforcement community, and a number of police departments, government agencies (Federal Air Marshals and the Secret Service carry the round) and certain military units (the Coast Guard, for instance) still carry sidearms chambered for the round.


Why Is .357 Sig Ammo So Hard To Get Then?


357 sig ammo

Unfortunately, the public never quite warmed to the cartridge, so pistols in .357 Sig and .357 Sig ammo are both a little harder to come by. Since the number of manufacturers making pistols chambered in this cartridge has dwindled, fewer people are buying the guns and thus aren't buying the ammunition - so less of it is made.


Additionally, it's not the easiest cartridge to make brass for. Ammo makers can't use .40 S&W brass nor 9mm brass; it's a shortened, bottlenecked 10mm casing. Not many pistol rounds are bottlenecked; the only other one that's anywhere close to common is the Tokarev round and good luck finding that in stores.


Since not many people own the guns and aren't buying the already harder to make ammunition, a lower volume of rounds are made and they sell for higher prices.


So yes, it's not easy to find it at the local B&M gun store. Plenty available online, but the point of brick and mortar retailers in this day and age is convenience - nothing convenient about a round you have to go on the internet to get.


That said, if you did, there's some great rounds out there. You'd be hardpressed to find a better choice of self-defense ammo, as .357 Sig outperforms even 9mm +P...and if spending on premium defense rounds, isn't that much more expensive when you get down to it.


Good Number of .357 Sig Guns Available Though


pistol for 357 sig ammo

Take heart, because if you want a .357 Sig (and why wouldn't you?) there are still a good number of guns available that are chambered for the cartridge.


Naturally, Sig Sauer makes most of them. They made the cartridge, so one might as well carry the same brand of gun. Not only will you have THE gun made for the cartridge, you'll own a Sig - and that means you get to sneer at plebiscite Glock people, because frankly they get annoying.


You don't even have to spend much; outside of certified pre-owned pistols, there are budget Sigs that can be had for less than $600 or less in most stores. The SP2022 and P250 can both be had for less than $500 in most stores and the P320 - essentially a P250 with improvements - is not much more than that.


Glock makes a line of .357 Sig pistols too, including full-size, compact and subcompact models.


Smith and Wesson used to make the M&P and M&P Compact in .357 Sig, and reportedly still will do so on request. The M&PC is an amazing CCW piece, so it may be worth ordering from the factory.


Top Tip - most .40 S&W pistols can be converted to .357 Sig by simply swapping the barrel. The round even fits in the magazine in most cases. Some guns may require a new firing pin, but many don't. Simply drop in the new barrel and away you go.




Sam Hoober 

About The Author


Born in southeastern Washington State, Sam Hoober graduated in 2011 from Eastern Washington University. He resides in the great Inland Northwest, with his wife and child. His varied interests and hobbies include camping, fishing, hunting, and spending time at the gun range as often as possible.

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