September 8, 2013

Glock GL31 .357 Sig

The basic concept of the .357 SIG is to deliver the same stopping power of the feared and respected .357 Magnum revolver cartridge from a semi-automatic pistol. The .357 Magnum round, featuring a 125-grain bullet fired from a 4-inch duty revolver, is widely recognized to be a top-flight fight stopper. Unfortunately, the recoil and flash of this combination also has few equals.

Power and controllability have long been issues in pistol cartridges, as witnessed by the love/hate affair with 9mm rounds. Handgunners love to shoot the soft-kicking 9mm, but they don’t have confidence in the 9mm’s one-shot stopping power. A compromise has been to cram as many rounds in the handle as possible, essentially trading high capacity for power.

The .357 SIG cartridge seeks to split the difference, offering the smaller rim diameter of a 9mm with nearly the punch of a .40 S&W. The Hodgdon No. 27 reloading manual says, “The .357 SIG is the .40 S&W case necked down to 9mm and effectively duplicates the .38 Super.”

But even the best round in a sorry pistol package would be of no use to anyone, so we went a-searching for handguns that could fire the .357 SIG effectively.

Glock adapted this same pistol to other cartridges, including the .357 SIG, and we found the fully loaded GL31 handled much like the model 17. If you have ever felt that the Glock pistol chambered for .45 ACP or 180-grain .40s were somehow out of sync, then the .357 SIG is a more natural fit.

Glock GL31 .357 Sig

Courtesy Gun Tests

Among the Glocks, the GL31's large frame offers the most sight radius and comfort while shooting.

From the standpoint of recoil, however, the loss of gross weight could be seen as a detriment. Even in the full-size GL31, the shooter becomes aware that he has just launched a hefty round. But because the projectile is light, the recoil pulse is over quickly, and the recoil is predictable. In particular, due to reduced bearing surface of the bullet traveling through the barrel, the shooter feels little torque when he fires the gun. Also, with the amount of propellant inside the oversized case, velocity is high and the bullet spends little time inside the barrel.

In fact, the GL31 produced the highest velocity overall, firing the Federal Premium 125-grain JHP at an average velocity of 1,364 fps. The Speer Gold Dot Hollowpoints (GDHP) rounds averaged a tick behind at 1,358 fps. The Winchester round-nosed flat points described as target or training ammunition averaged a whopping 1,336 fps. That means muzzle energy ranged from 496 to 517 foot-pounds.

To put this into perspective, the muzzle energy generated by some previously tested pistols in .45 ACP ranged from 276 foot-pounds (Winchester 185-grain full metal jackets) to 331 foot-pounds firing the Winchester 185-grain SilverTip HP. In another test, Winchester’s .40 S&W 180-grain FMJ produced about 400 foot-pounds. Returning to our lineup of .357 SIG pistols, even the small GL33 easily eclipsed these marks.

Glock GL31 .357 Sig

Courtesy Gun Tests

The fully loaded GL31 handled much like the Model 17 9mm. If you have ever felt that the Glock pistol chambered for .45 ACP or 180-grain .40s were out of sync, then the .357 SIG is a more natural fit.

Obviously, power out the muzzle isn’t an issue with the .357 SIG, but how does that oomph register behind the gun? We found that working from a rest or standing, the GL31 is the easiest of the Glocks to shoot. There is plenty of frame to rest on a sandbag and the gun offers 6.5 inches of sight radius. Felt recoil is sharper than with other calibers, but in this case the force is expressed directly rearward, not as muzzle flip. We theorize that since more of the energy is coming straight back into the hand, instead of torquing upward, the impact of the recoil seems greater. Working from a rest, for example, it is the wrist that takes a beating. This is because the recoil has nowhere to go but up.

In testing the Glock pistols, we felt the increased kick from this high-pressure round, but we didn’t think the wrist fatigue was overwhelming. However, we did feel more impact as the gun sat back into the hand. A firm grip with a focused intent is needed to fire the Glock .357 SIG pistols effectively.

The GL31 proved the least objectionable to shoot and also produced the most accuracy. While five-shot groups averaged a respectable 2.4-inch diameter with the Winchester FMJ rounds, the GL31’s performance with the hollowpoints were exceptional. The Federal shot the smallest single group (1.2 inches), but what impressed us more was the performance of the Speer 125-grain GDHP round, varying only 0.1 inch across the groups for an average of 1.9 inches.

Comments (22)

Like the Texas Ranger said when asked" Why do yall carry a 45?" he responded "because they don't make a 46!"

Posted by: Sharps | September 29, 2009 9:44 AM    Report this comment

From published sources for the 123-5 bullets try,
AA#9, VV N350, N105, & 3N38, and BLUE DOT. If you want more power, use a throating reemer that gives .030" or more bullet jump, then polish with progressively finer grades of emmery paper to #600.

Posted by: lotoofla | September 11, 2009 8:49 PM    Report this comment

Michael P - What load are you using to get to 1450 fps? I'm getting 100 fps less than that. Good comment on buying new mags when changing calibers.

Posted by: MARK W | September 11, 2009 12:25 PM    Report this comment

Flogger Should Have said I have had no missfires

Posted by: flogger11 | September 10, 2009 9:34 PM    Report this comment

Do you, Charles S, really consider the G32 .357 to be a little 'mouse' gun?
I find it better to conceal with less printing on the grip with a belted holster. Nicht Wahr?

Posted by: der uffz | September 10, 2009 8:02 PM    Report this comment

Some of the comments I've read thus far out completely out-of-whack.

First, any Glock .357 barrel will fit in the equivalent .40S&W frame. Striaght change-out, good-to-go. I bought new mags so the cartridge is accurately depicted on the mag so I don't have stupid errors.

My G33 is a pleasure to shoot. Perceived recoil for me is less than the 180-gr .40 S&W. My perception, YMMV. I had a choice of .40 S&W - I bought a G33 .357 barrel and shoot 125-gr GDHPs at 1450 fps. Much better, much more effective and the equivalent of the .357 mag. Everyone always compares their cartridge to such gold-standards so why choose an approximate like the .40 S&W?

Posted by: Michael P | September 10, 2009 7:48 PM    Report this comment

Interesting comment on the GSW's. A friend who lives/works in a somewhat gang saturated area said one of the "people" in the area bragged about his 9MM. My friends response was "I'll bet you've never seen a scar from a .45 have you?"

Posted by: 3percent | September 10, 2009 6:49 PM    Report this comment

I have A glock G27 Bought the Wolf 357 sig barrel it works very well in the gun and the ammo works well in the 40 mags have hand misfires with after shooting x amoumt of ammo in both barrels

Posted by: flogger11 | September 10, 2009 6:15 PM    Report this comment

I have the Glock 31 in 357 SIG. It shoots groups as tight as they say. I reload for it also and it is a challenge to not crush the case because of the short bottle neck. You can buy a .40 S&W barrel for it from Cheaper Than Dirt for about $100 and just drop it in. It uses the same magazine since the 357 SIG is just a necked down 40 S&W.

Posted by: MARK W | September 10, 2009 6:07 PM    Report this comment

I own 9mm, 40 S&W and 10mm handguns (G34, Steyer S40 and G20 C) and am often curious as to why the 10mm does not get mentioned in articles such as this which discuss controllability and power. I find the 10mm to be a perfect match between the two with more energy on par with the 357 mag and very easy on the hands (have to give the compensator some credit for that). In fact, my accuracy with the 10mm is about that with the G34 (long barrel 9mm) with thousands of rounds put through each. I chose my 20C for the last "5 plates" competition and it performed flawlessly and I had little hand shake after six 15round mags of 10mm. Given the power of this round, it seems that it should be included in these conversations since it is the most powerful round that one can get in a Glock.

Posted by: Dinglejak | September 10, 2009 1:27 PM    Report this comment

Stay away from Glocks.
I had a Glock and it was part of recall which Glock never notified me of. They informed the law enforcement agencies but no one else. I wouldn’t trust Glock products.
Do a search for yourself on Glock Recalls

Posted by: Silver Dollar | September 10, 2009 1:27 PM    Report this comment

.357 Sig is way too hot for a little mouse gun like the G32. The G31 is the way to go in this round; love mine but only get to shoot it occasionally due to pricey ammo.

Posted by: Dulrug | September 10, 2009 12:30 PM    Report this comment

I confess to being seduced on rare occasions by the lure of the market. However, there are very few people in the US today who actually need and depend upon the absolute reliability of Sig and Glock autos, or S&W and Ruger revolvers. For the rest of us, the market is interesting and fun, and most of us have enough disposable income to occasionally indulge in our hobbies. But the people here in the US (most emphatically NOT Europe) who use guns for a living, and actually shoot other people with them, are the people who have made Sig and Glock autos, particularly those whose calibers begin with "4," the leading guns in the US.

Having worked for years in hospitals, and dealing with GSW victims, I learned early on that the round nose bullet, particularly FMJ, is a bad choice for self-defense. I also learned that everything below .357 Mag in caliber/power is a poor choice for self-defense. Of all the GSW victims I've helped treat, the most incapacitating wounds were inflicted by .357 Mag, .40 S&W, and .45 ACP hollowpoints. Almost everything else was +95% survivable.


Posted by: Lee W | September 10, 2009 12:23 PM    Report this comment

In the days of yore, there was (and is) a necked down wild cat cartridge called the 38/45 Auto based on the .45 ACP case. The barrels, and reloading dies are still on the market and the power is less than the .38 Super.

Posted by: lotoofla | September 10, 2009 11:59 AM    Report this comment

If reliability were a factor, wouldn't those calibers like .357 Sig, .40 Corbon etc. be the big sellers in defensive calibers instead of .45, .40 and 9MM?
I shoot/love Glocks in 9MM, .40 and .45.
I have shot 10's of thousands (I'm not exaggerating)of cast bullets down their factory barrels with no problem at all, other than having to replace worn out springs.

Posted by: 3percent | September 10, 2009 11:50 AM    Report this comment

My thought was a conventionally rifled barrel would allow shooting lead bullets in practice. In addition, bottle neck pistol rounds have it all over straight wall round when it comes to feeding. I don't care how well your pistol feeds, a .40 CorBon, a .357 Sig, a 7.62x25 will all feed more reliably with more different bullets and sometimes poor ammunition. I have a .40 Glock that I have owned for a couple of years without firing. Hopefully I am going to get around to it. James T.

Posted by: Troy | September 10, 2009 11:35 AM    Report this comment

To the best of my knowledge, James Troy, I believe that's true but can anyone explain to me the advantage in a defensive handgun?

Posted by: 3percent | September 10, 2009 11:02 AM    Report this comment

James Troy is my name. All my friends call me Troy. Guess what? The T after James stands for Troy but in the future I will try not to confuse your ---computer. James T.

Posted by: Troy | September 10, 2009 10:50 AM    Report this comment

I was under the impression that you could drop a Lone Wolf barrel in .357 Sig into a .40 Glock and rock and roll. Am I misinformed? Anyone please?

Posted by: Troy | September 10, 2009 10:45 AM    Report this comment

What's the advantage of a 357 Sig over a .40 S&W? Overpenetration? Scarcity of ammo and components? As far as energy, you can't get more energy by necking a cartridge down, just more FPS. Why not neck down a .45 ACP? That would make about as much sense.

Posted by: 3percent | September 10, 2009 10:28 AM    Report this comment

I love this gun. I only wish I was employed and could acquire a couple of them, one for my wife and one for myself.

Posted by: patriot | September 10, 2009 10:16 AM    Report this comment

For Glock .357 concealled carry, I use the G32.

Posted by: der uffz | September 10, 2009 9:55 AM    Report this comment

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