[.357 SIG]: Best Ammo & Post-Mortem Review

.357 SIG is a weird cartridge.  

It’s one of those less-common cartridges kinda like .44 Magnum that gets a lot of hype but no one really uses it, and no one knows why.  Nobody really knows what to do with it at this point.

It was intended to be a contender in the pistol world alongside the 9mm, .45ACP, and the (at the time) recently-released .40 S&W.

Nowadays, the .357 SIG hasn’t really caught on except in some niche circles…but it hasn’t gone away either.

357 sig comparison
(left to right) 9mm, .357 Sig, .40 S&W

I’ve heard all kinds of things about the .357 SIG over the years, some good and some bad, some true and some false.  I think it’s time to set the record straight.

There’s nothing inherently bad about the .357 SIG, and it does have a small but loyal following that swear by it.  

There’s also a reason why it hasn’t really caught on.  A few reasons, actually.

Let’s put aside the hype and really look at the truth behind this cartridge, that way you can decide for yourself what to do with the .357 SIG.

Table of Contents

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History of the .357 SIG

Back in the early 90’s, someone at firearms giant SIG Sauer got a bug up their butt about the .357 Magnum.  Specifically, they wanted to recreate 125gr .357 Magnum performance out of a four-inch revolver, but in an auto-loading pistol.

Double Action S&W 686 in .357 Mag
Double Action S&W 686 in .357 Mag

SIG partnered up with another big name in the firearms world to make this happen: Federal Cartridge, now called Federal Premium Ammunition.  You will know this name from the massive slice of the ammo section they own at your local sporting goods store.

Together, they set out to recreate the performance of the popular .357 cartridge in a bottle-necked cartridge that would have less recoil, but similar overall ballistics.

They worked to create a cartridge based on the 10mm Auto case that could be necked-down for a .357 Magnum projectile, and that could handle higher pressures to surpass the .40 S&W, and be on par with the .357 Magnum.

Around 1994, what they ended up with was a cartridge that was a hair longer than .40 S&W, with slightly less recoil, firing a 125gr (almost 9mm) bullet with .357 Magnum energy.  Specs stated it would have an 18-degree shoulder, a short neck measuring 0.275 inch, utilize standard small pistol primers instead of magnum ones.

Thereafter, they would switch to a 9mm projectile that was slightly smaller for ease of reloading, and better velocities.

Shortly after, SIG released the SIG Sauer P229 which was the first commercially-produced firearm chambered for the new cartridge.  It could also be easily modified to shoot the .40 S&W simply by switching out the barrel.

Sig 229
Sig 229

The P229, a variant of the popular P226 designed for the higher pressures and increased slide velocities of the .357 SIG and the .40 S&W.  

As far as the cartridge itself, it found success with a number of LEO agencies, but it didn’t quite reach the widespread adoption that SIG and Federal hoped for (for reasons I’ll get to in a minute) but this adoption by police forces is likely what has saved the cartridge.

Performance of the .357 SIG

Performance-wise, SIG and Federal hit it out of the park with their new round.  They hit all their design goals and ended up with an extremely accurate and flat-shooting round that matches the .357 Magnum, even if only the smallest .357 Mag bullets.

While .357 Magnum starts to outstrip the .357 SIG in terms of raw energy with anything bigger than a 125gr projectile, the .357 SIG still does a great job of replicating the ballistics, particularly the very flat trajectory, of its design inspiration.

Caliber Comparison

Of course, the nature of .357 SIG pistols versus .357 Magnum revolvers means that you get more or less double the number of rounds on tap with the SIG which is more than enough to outweigh the lesser velocity and energy for me.

Modern firearms doctrine has very much moved on to “more bullets = more better” instead of “bigger bullets = more better” so the .357 SIG actually exceeds the original in this regard.

The rounds are also smaller and lighter than the .357 Magnum’s, which makes carrying extras a lot less of a pain.  That said, impact performance, particularly with the larger 160gr bullets at the upper end of the .357 SIG’s size range is still impressive, and is certainly an improvement over the 9mm (even though the difference is getting smaller and smaller every year with improvements in projectile design).

For example, the Virginia State Police have recorded multiple instances where attacking wild dogs have been stopped by a single .357 SIG round, and investigations into the incident suggested that a single shot with a 9mm, given the same impact point, would have been insufficient.

Now, this isn’t super scientific I know, so we’ll get to some actual numbers in a second, (and also it kinda sounds like Virginia has a wild dog problem, wtf Virginia?) but it is representative of some real-world usage of the cartridge, and some potential advantages it has over the far more popular 9mm.

The one thing that I think really holds the cartridge back is muzzle blast.  The sheer sound and force of the projectile makes it a little less than comfortable to shoot for most folks, although actual recoil and muzzle flip are on par with the .40 S&W.

Finally, the bottle-necked nature of the cartridge means that feeding problems are basically non-existent.  I’ve never once experienced a failure to feed or failure to go into battery with a .357 SIG firearm, which is no small feat.

.357 Sig Vs. Ballistic Gel
.357 Sig Vs. Ballistic Gel

This is because of that bottleneck design that causes the round to be fully seated as the slide goes into complete battery, after essentially being straightened and aligned by the larger section of the chamber before the namesake bottlenecking of the chamber.

This also works well with the traditionally very flat-nosed bullets you find in the .357 SIG.  Flat-nosed bullets, whether hollowpoints or FMJs, are typically avoided because the flat plane of the nose can catch on feed ramps and cause malfunctions ranging from the annoying to the downright life-threatening.

No such worries with the .357 SIG.  The design means no problems feeding flat-nosed FMJs or notoriously finicky hollowpoints.

Why It Never Caught On

Of course, all of that sounds really great, right?

So why aren’t we all carrying .357 SIG guns instead of 9mm, .45, .380 or .40?

.357 Sig is a great cartridge…but no one uses it?

Actually, there are a few reasons.

First and foremost, while SIG and Federal really wanted a compact, auto-loading cartridge that replicated the oomph of the .357 Magnum…not a lot of other people really cared.  

You had the .40 S&W that was still new but had been out long enough to gain a bit of a following, especially amongst law enforcement and those who wanted an intermediate cartridge between 9×19 and .45 ACP.  While .357 SIG is superior to .40 in velocity and muzzle energy, the numbers aren’t enough to make a huge difference, certainly not in the minds of most people.

In general, not a lot of folks care enough to read all the little numbers on the back of the ammo box, so .357 SIG’s improvements over .40 S&W weren’t widely realized until later when it was arguably too late for the round to really take off.

Really it was just a case of a cartridge filling a need nobody really had.

Those with a preference for higher-capacity would choose the extra 4-5 rounds they could get out of a similarly-sized 9mm over the .357 SIG, those looking for an intermediate handgun round already had .40 S&W, and those still ascribing to the “bigger bullets” theory still had the venerable .45 ACP.

So who was the .357 SIG really for?  

Law enforcement.  It seems like SIG and Federal wanted a round that would appeal to LEO’s and give them the easier shooting experience of the .40 with a little more power and a flatter trajectory.

Judge Dredd would have carried .357 Sig, I’m sure of it!

And they did that.  

They absolutely succeeded…it just wasn’t enough to pull more than a few state and federal agencies away from the calibers they already used.

That lack of widespread adoption by law enforcement is what killed the .357 SIG’s chances at ever rubbing shoulders with the “big three”, and modern doctrine emphasizes shot placement and capacity over long-range accuracy or stopping power.

Newer bullets with better terminal performance have lessened the gap between calibers, and modern 9mm ammo isn’t far behind .40 or even .45 ACP performance wise, but allows for many more rounds on tap and a much more controlled shooting experience.

That’s why most police and even military handguns are going to be wielding 9mm over anything else.

Maybe if more police departments, particularly large state agencies, had picked up the .357 SIG, things would be different, but as things stand, there aren’t a whole lot of folks who see the need for a .357 SIG handgun.

.357 SIG Today

Modern .357 SIG firearms like the P229 and the GLOCK 37, 38, and 39 are still carried by a number of law enforcement agencies, and even some federal agencies like the Federal Air Marshals and the Secret Service.

The Glock 32 is also popular with CCW civilians and as an off-duty carry gun for police officers.

500
at Brownells

Prices accurate at time of writing

Prices accurate at time of writing

A lot of state agencies that let officers have a bit of leeway with what they carry have also continued to allow the .357 SIG to be carried.

However, while these groups continue to use .357 SIG, very few new agencies are picking up .357 SIG, and I was unable to find any evidence of a major law enforcement agency switching to it after 2014.

Nowadays, it’s hard to even find .357 SIG on store shelves which is more or less the kiss of death for a pistol round.  Niche rifle rounds can find success with reloaders and can even rumble along in relative obscurity and be fine.

The sheer massive availability of the 9mm, .45 ACP, .380 ACP, and .40 S&W, and thus the comparatively cheap prices of these rounds, means the .357 SIG will never really be able to compete, not in the wider commercial market.

The Future of .357 SIG

Where will .357 SIG be in five years?  Ten?

I really don’t know.  I know that most everyone in law enforcement is going to 9mm.  I know most carry aficionados are going to 9mm. I know that most everyone that used .357 SIG does so for emotional “but I like it” reasons rather than reasons of science.

But we gun people are an emotional lot, prone to thinking with our gut or our hearts instead of our heads.  Sure, the .357 SIG will probably never be as popular as the 9mm, but will it go away?

I don’t think so.  That core of loyal users that have probably been shooting .357 SIG since the mid-nineties doesn’t show any signs of giving up on the cartridge

Best .357 Sig Ammo

If you do carry .357 Sig or you are planning on it soon, there are some great options when it comes to ammo. The downside? Well, .357 ain’t cheap compaired to some ammo – but it isn’t bank breaking either.

1. Speer Lawman, 125gr 

.357 Sig is not designed for plinking, it’s meant to be a duty cartridge and carried and serious people. As such – there isn’t much in the way of cheap plinking ammo, but there is decent priced training ammo.

22
at Lucky Gunner

Prices accurate at time of writing

Prices accurate at time of writing

The Speer Lawman fills that role exactly. Reliable, clean shooting, and less than half the cost of carry ammo.

2. Sig Sauer 125gr V-Crown

Of course, Sig Sauer would offer some of the best duty ammo! As the testing done by Lucky Gunner prove, this ammo performs when you need it most.

Best Duty/Defense .357 Sig Ammo
21
at Lucky Gunner

Prices accurate at time of writing

Prices accurate at time of writing

Parting Shots

In short, I think the .357 SIG offers some definite benefits and is probably here to stay for at least a little while yet.  It’s a good cartridge with good performance, and despite not being the success SIG and Federal wanted, nothing can change the fact that this oddball cartridge works.  

Maybe that’s enough

What do you think of the .357 SIG? Do you own one, or are you thinking of getting one?  If you’re interested in more common calibers, take a look at our Best 9mm Ammo and our  Best .45 ACP Ammo articles!

22 Leave a Reply

  • M2MikeGolf

    I think the Army should have adopted the .357 Sig in its new M17. I have an M17 and a couple of 320c’s. I have a .357 sig conversion. (I also have a 229 in .40/.357/9mm). The Army still has time to consider as a conversion kit to .357 would be mildly expensive, not counting ammo of course. But heres what the Army and everyone else isn’t getting, the .357 Sig would also be a great sub machine gun round. It even outperforms the old Soviet PPsH 7.62 Tokarev round and the original high performance bottleneck round, the C96 Mauser 7.63, at one time being “the most powerful handgun round” in the world. I think it would make a great choice for a military cartridge. Just ask the Texas DPS and Rangers if you don’t believe me. As for me, I was an infantry master gunner for 24 years. Based on my experience, soldiers would love it, particularly a sub round and platform.

    1 second ago
  • 357Thom

    I carry a p226 in 357 sig as my "winter" EDC in New Hampshire. This is the land of heavy winter garments, requiring good penetrating power in the worst case scenario, and offering easy concealment on a daily basis. Also this is my any-time hiking companion- equally adept at 2 and 4 legged predators. The P226 is VERY easy to point, and follow up shots are as quick and more reliable in my hands than my 9mm G19, possibly due to the superior DA/SA trigger of the P226. I also have the .40 barrel to swap in for cheaper practice sessions. I love the way the cartridge sounds and feels. Thanks for a very interesting write-up.

    2 weeks ago
  • Scott Hodges

    I carry a Glock 32 and was forced to use it the damage it done to the perp .was devastating . I will never carry anything else

    3 months ago
  • zondo

    I’ve spoken with many Ex LEO and a few Ex FBI agents at gun shows and every one of them said the same thing the only reason the 9mm was chosen by the FBI and LEO was not because the 9mm was a better because they even said it wasn’t, it was because there agents and officers were only hitting their targets less than 30 percent or less of the time (look up the report) which they the LEO and agents blamed on recoil of 40SW and 357Sig and with the 9mm you got less recoil for faster follow up shots and 2+ extra rounds yet the know the standard FBI and LEO 9mm round is now a +p and +p+ which know that so called recoil that they blamed on the 40sw and 357sig is worse with the 9MM +p and +p+ then it was with the 40SW and 357SIG. So rather than offering better training for their officers and agents with the 40SW and 357 sig both which they all said were a much better and both were a more powerful round with taking down people especially with the 357 sig when loaded to where it originally was supposed to be (which originally was 1,450 + feet per second) for a 125 GR bullet and which out performs any 9mm +p or +P+ round) they watered the round down to 1350-1375 and then opted to go the less powerful 9mm which is actually under gunning there officers to a less lethal round. Remember all the technology that everybody keeps saying went into the 9MM to make it better also went into making the 40 SW, 357SIG and the 45ACP better which know the 45acp has +p rounds that were never heard of ten years ago. Please watch the following 2 videos below in their entirety and just maybe if you can put politics aside you will understand how the 9mm though a good round and can get the job done in most cases is not the perfect defense round that people want it to be. https://www.youtube.com/watch?v=LTTDgZZZFa0 https://www.youtube.com/watch?v=U4DsaBrohV0

    6 months ago
  • Bill

    I have a Glock 35 and I would like to get a drop-in .357 SIG barrel, and .357 SIG mags to go with. With the 5 inch tube I think it would easily be marching in .357 Magnum territory

    6 months ago
  • Ken

    First, great article. I'm not sure it will go away either, at least I hope not. I just switched from 357 Mag to 357 SIG as a woods or trail gun. I am getting older, and after years of shooting, the 357 Mag makes my elbows sore after some time on the range. The 357 SIG is a great cartridge that, in my opinion, suffers mostly from misinformation from the 9mm fan boys (sorry for the characterization but I feel it explains the issue best). Those that say the 357 SIG has excessive recoil are simply just recoil sensitive. Why do you think the FBI switched back to the 9mm? Reason #1 - it's easier to shoot and the report states that (less recoil, less muzzle blast, etc.). Also, why should I believe that "modern bullet design" only effected the 9mm cartridge? That's like saying the 9mm projectile is much, much better than the 380 as I've heard some "gun experts" say. Seriously? Are we really expected to believe this? And finally, saying the 9mm +p+ and +p++, etc "approach" the ballistics of the 357 SIG and/or MAG would be akin to making the claim that a 357 MAG fired from a lever action carbine "approaches" the muzzle velocity of the 223/5.56mm. Yeah, technically that's true, but trying making that comparison is somewhat ludicrous. The 9mm is a fine cartridge and there are good reasons to choose it over the 357 SIG however none of the reasons mentioned above are good reasons, at least in my opinion. I apologize for the rant but this whole "the 9mm is just as powerful as 357" crap really gets on my nerves.

    6 months ago
  • Alex

    357 Sig is my favorite pistol round. It can be counted on to end a bad situation quickly. It’s a shame the US Military never adopted it, but at least the secret service uses it to protect our president. It’s more powerful then any other common pistol caliber and shoots pretty soft. It also wins in the area of psychology, with the perceived muzzle blast, most will call it a day. You can pick up a 357 Sig sp2022 on the cheap and be having fun at your range in no time.

    7 months ago
  • Keith

    One of the biggest reasons I bought an G23 back during ammo shortages was ability to convert to 9mm. Last month mistakenly bought a box of .357Sig. What better reason to buy a barrel for a hundred bucks. Now have a 3 caliber pistol.

    7 months ago
  • conrad

    I think the round belongs to the true aficionado. There are never feeding problems, and the flat trajectory is quite desirable. However, a person has to realize that the 9mm+P+ and the 9mm+P++ (subgun ammo) runs right in there with the .357 sig.

    8 months ago
  • zondo

    I love the .357 sig just like the 10mm and 40SW all these rounds just didn’t get the recognition they deserved. Going to many gun shows and speaking with many ex LEO and FBI that loved the rounds it was obvious that politics pushed the 10mm 40SW and .357 sig to the side. According to most of the ones I spoke with the complaints of it being loader and harder to handle and slower backup shots was all BS and stature of the person and practice was more of the issue not the round. Many if not all said the same thing maybe better practice and more practice with the round would have been better than going backwards to the 9mm. Many LEO and Ex FBI I spoke with said they seen it coming with the military accepting the 9mm which kicked off the so called Domino affect with police following the military then civilians following what LEO was carrying pushing aside the 40SW and the.357 sig two rounds that were better than the 9mm in many aspects.

    10 months ago
    • Jaime Spencer

      Good feedback. I’m a civilian shooter and love my two Glock 22’s. I begin reading this stuff then become insecure about my purchases and wonder what I did wrong and if I got the wrong gun or ammo etc. I’ll keep my .40 S&W pistols and ammo and also look forward to a .357 Sig pistol as well. Thanks man!

      10 months ago
  • Cliff

    Underwood 125 grain GDHP coming at 1475 FPS. Over 600 pounds of energy at the muzzle.......

    10 months ago
  • Raymond

    Underwood ammo.

    11 months ago
  • Michael Berman

    The .357 sig is my favorite handgun round. It has more energy with less recoil and a flatter trajectory than a .40 sw....and I love that round too. I have no doubt that if the .357 sig had been introduced first, it would be the success that the 40 sw is now. The .357 magnum has always been a well respected cartridge....certainly not the biggest or baddest cat in the jungle, but ballistically a very competent round. The 357 sig is NOT a necked down .40 as some people believe but rather a necked down 10mm case. I owned a g3 glock 23c and bought a .357 sig barrel for it so I can used for both calibers. I thought the .357 would be more punishing to shoot because of it’s higher energy but just the opposite is true. Granted I have a factory compensated barrel but I just love the round. It is the perfect round mated to the perfect pistol. No my glock is not stock but I cannot imagine a better pistol than what it has evolved into! Might eventually pick up the 9mm barrel for it too!

    11 months ago
  • Ryan

    Awesome article. I was curious why the caliber wasn’t more popular. I really enjoy shooting my SIG Pro 2340. I have hands like a gorilla and the gun fits me well. My friends who shoot it love the round but find the palm swells too large. I can’t really tell much of a difference between this round and my .40’s. Both seem to have the same recoil. I agree with the emotional attachment. Best guns I ever had were the guns I sold. :-). If I didn’t like the feel of the gun so much, it wouldn’t be hard to part with the caliber. I’m not really one to jump on the next fad caliber but Sometimes you just never know if they will become popular. Ever since picking up a 6.5 Creedmoore, my .308’s have been missing me something awful. I can’t imagine that caliber fading away for a long time.

    1 year ago
    • Michael Berman

      I don’t think it will fade away either. Mine has milder recoil than when I shoot 40sw through the same platform (have a glock 23 with both the 40 and 357 barrels ) Honestly I didn’t see the need for the round either...and then I saw the energy numbers, the cost of the ammo online, and felt the recoil which was very very manageable. Now I can’t figure out why everyone doesn’t shoot it!

      11 months ago
  • John In FL

    I remember reading it also performs better than 9mm, 40sw and 45acp vs windshields. I trust my life to the 9mm, not necessarily because “more rounds=more better”, but because I can practice with it at a decent price/rd and because I believe if I do my part both the platform and the round will gdo their job. I also like the 45acp and .40sw depending on the platform. I think .357magnum is awesome, but I decided to carry a semi auto and not a revolver. No experience with the 10mm or FN 5.7

    1 year ago
    • Michael Berman

      10mm is a brute and really not that bad to shoot but the 357 sig is sweet, flat shooting and accurate. It also has quite a bit more energy than the 40sw, 45 or 9 mm. I buy my ammo on line and get if for a reasonable price...not as cheap as 9mm but on par with .45. I converted a glock 23 to shoot both calibers by the addition of the 357 barrel. Even my mags handle both rounds. While I loved my Glock 20 when I had it, the 20 was just too big for my hands whereas the glock 19/23 frame fits me perfectly!

      11 months ago
  • Hammer

    It may be the "best semi auto cartridge ever developed" in terms of numbers, but the things that it's "best" at just don't really matter for the vast majority of users in the real world. Just ask an ER doc if he can tell the difference between a 9mm wound and a .357 Sig wound.

    1 year ago
    • Michael Berman

      No one is dissing the 9mm but to suggest there is no difference between 350 ft/lb of energy and 500 is a bit ludicrous. By that standard no one need ever own a 300 win mag...they could just shoot .308!!!!

      11 months ago
  • Mike Hugesack

    I thought the .357 Sig was already dead until I discovered that my local PD still uses it as their duty carry. It really should be more popular. It is the best semi auto cartridge ever developed. Who knows why inferior products become mainstream? I mean c'mon, how in the hell is rap/hip hop more popular than than the sounds rumbling from my arse after eating a head of raw broccoli?

    1 year ago
    • Michael Berman

      It really is a great round deserving of far more popularity. Air marshalls use it as do some highway patrol who prefer it for its penetration. It is a dramatic increase in power from the 9mm while being able to use the same frame sizes. If I had occasion to engage targets at longer distances, the 357 sig would be my top choice in a semi auto pistol. For protection from large game it would be my second choice after a 10mm auto. I definitely prefer it to the big 3 (9mm, 40sw, 45acp )

      11 months ago
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