I Dig the .357 Sig

By Tom McHale

USA –-(Ammoland.com)- I dig the .357 Sig.

In fact, I dig it so much, I feel like I’m on a one-man campaign to help boost it into the shooting mainstream.

One of the biggest gripes people have about the .357 Sig cartridge is the cost, but that becomes a non-issue as more people start to use it. Volume begets cheapness – the more they make, the lower the cost.

Whatever your position in the caliber wars, you have to admit that 9mm is making a resurgence as a great defensive caliber, and hey, .357 is a 9mm on steroids, right?

What is the .357 Sig?

Some folks refer to this cartridge as a necked-down .40 Smith & Wesson. Conceptually, that’s kinda true, but there are technical differences. The cartridge base is the same dimension and the main part of the case body is the same diameter, but the .357 Sig case is not made from a .40 S&W case. The projectile is the same as a 9mm at .355 inches diameter.

Because of these similarities to the .40 S&W, you can often just swap barrels to change your pistol from .40 S&W to .357 Sig or vice versa. Magazines are generally compatible between the two calibers as well. Always check with your particular handgun manufacturer first before embarking on caliber changes.

If you want to understand the benefit of .357 Sig, just think this. It’s got the magazine capacity of a .40 S&W in any given gun, and it has a 200 to 400 foot per second velocity advantage over 9mm, depending on the load. While .357 Sig can’t match the specs of those uber-macho 158 grain .357 Magnum loads, it does compare favorably with 125 grain .357 Magnum.

One other thing to note. The .357 Sig is a bottleneck-shaped cartridge. This provides another hidden advantage – feeding is exceptionally reliable.

With any of the four .357 Sig pistols I currently have (Sig P226, Sig P229, Glock 32 and Glock 31), I can limp wrist like Pee Wee Herman and the guns will still cycle properly.

Ballistic Science

Earlier I mentioned that .357 Sig approaches .357 Magnum territory, but from a semi-automatic pistol. It’s close. Real close. To see how close, I went out to the range and clocked a slew of them using a Shooting Crony Beta Master chronograph placed 15 feet down range. Here’s what I found.

Of all the loads I tested, average velocity was 1,363 feet per second, and that includes those fat and (relatively) slow 180 grain hard cast cruisers from Doubletap Ammunition.

Recoil

Felt recoil is a subjective thing. What I consider “snappy” might be considered tame by someone else, say Chuck Norris. Fortunately, like muzzle energy and momentum, recoil energy can be calculated as well. The easiest way to compare recoil of one load versus another is to head over to my buddy Andrew Chamberlain’s Cartridge Comparison Guide ( tiny.cc/gg7zdx ) . He’s a math whiz and does engineering stuff. Whatever it is that he does, he shoots a lot, breaks out his slide rule and writes it all down in the book.

According to the Cartridge Comparison Guide, an “average” .357 Sig load compares to other “average” loads as follows:

Geeky Info with No Practical Application

You’ll hear people describe the .357 Sig as a “flat shooting” cartridge. It certainly is, but I’m not sure what difference that makes at normal handgun ranges. Nonetheless, I get a kick out of plinking at stuff with a Sig Sauer P226 at 100-yard distant targets. Why not?

If you do some cocktail napkin math, you’ll find that a 9mm, 124 grain bullet, fired at 1,150 feet per second, will drop about 10 inches over 100 yards. That’s assuming the sight is ½ inch above the bore, and your zero is at 25 yards. A 125 grain .357 Sig bullet, moving at 1,400 feet per second, will drop only about 6.8 inches under the same conditions.

There are eleventy-million variables, but that’s the rough math. So yes, it’s a flatter shooting round. Is that relevant? That’s up to you.

An Epistle on Expansion

A little velocity goes a long way when it comes to reliable expansion. An extra 100, or even 50, feet per second in velocity can make all the difference as to whether a projectile expands or not. Just to be clear on that statement, I’m talking about expansion performance in more real world scenarios.

Any modern hollow point bullet will expand if you shoot it into water or pure ballistic gelatin – that’s an ideal situation to get perfectly expanded bullets suitable for the cover of Ballistics Freak magazine.

Consistent bullet expansion performance starts to get iffy when you introduce barriers in front of the water or ballistic gelatin – things like clothing, coats or even hard barriers like glass or car doors. Softer barriers like clothing can clog up hollow points, and harder barriers tend to press the cavity inwards instead of outwards.

In my ammo expansion testing over the years, I’ve noticed one universal truth: velocity rules once you start introducing barriers. Ammo engineers can make bullets that expand at virtually any velocity. They don’t create bullets that expand too easily, however, as penetration is the other fundamental goal. Too much of one comes at the expense of the other. Under controlled conditions, they can make a bullet that expands every time within a certain velocity range. Where things get dicey is with barriers. That makes performance unpredictable. However, driving that bullet a bit faster tends to make it work more consistently and overcome the barrier uncertainty.

Purely in the name of science, I decided to do something a bit on the silly side. It’s not a realistic test, unless bad guys and other nefarious home invaders use body armor made of kitchen cutting boards, but it does illustrate the benefit of velocity.

To illustrate my “velocity rules” theory, I decided to try a ridiculously tough (and unrealistic) barrier in front of the ballistic gelatin – a plastic kitchen cutting board. It’s about ¾ inches thick, tough, and resilient enough to clog up hollow points. As you can see in the photo, the only cartridge among those I tested that managed to expand after passing through this expansion limiting nightmare, was the .357 Sig. Just for kicks, I also did similar “tests” shooting through things like stone floor tiles, bags of flour, pine boards and the Sunday Edition of the New York Times (I wanted to see if .357 Sig could penetrate a big pile of BS. It did.) Without fail, the .357 Sig performance exceed all others in comparison.

What does that tell us? Not much, except that it’s fun to shoot through silly things to see what happens. But seriously, I think it does provide at least some indication that extra velocity helps overcome some of the challenges that projectiles face. I’ve seen similar indications from shooting identical bullets from long and short barrel guns. The bullets from longer barreled handguns have more velocity and tend to perform better. Physics or something.

Feelings

Here’s the thing. For all the talk about velocity, we’re still talking about a standard weight 9mm bullet, so recoil is manageable. Yes, “felt recoil” is a totally subjective thing, but to me, the .357 Sig shoots softer than an equivalent gun chambered in .40 S&W.

The math says otherwise, but hey, I’m entitled to my feelings, right?

Is it right for you? Maybe. Is it NOT right for you? Maybe. A number of law enforcement agencies at local, state and federal level use it, and they have to meet the requirements of a broad cross section of shooters, so that says something. Given that it operates at the higher level of the handgun recoil scale, it takes practice commitment. After all, the only thing that counts is getting hits on target. If you can do that, then all the other things like velocity and expansion results don’t matter.

I’m sticking with it. I got hooked on the .357 Sig cartridge with a Glock 32 and later a Glock 31. Recently, I upgraded to a Sig P226 and Sig 229. Already I’ve determined I’m never giving those up. The superior grip ergonomics of the Sig, combined with eight ounces of extra weight and real metal construction make it a sweet shooter in .357 Sig caliber. More on those Sigs soon.

About

Tom McHale is the author of the Insanely Practical Guides book series that guides new and experienced shooters alike in a fun, approachable, and practical way. His books are available in print and eBook format on Amazon. You can also find him on Google+, Facebook, Twitter and Pinterest.