Does 357Sig Beat Up Guns

[jtmckinney]

I bought an older Glock 24C (40sw) and got bulged brass with factory loads (unsuported case head). This made it unsatisfactory for what I wanted the gun for which was to load up at near max for a side arm when hunting. I posted in the sale/trade forum and bought a new 357 Sig barrel for it that has performed perfectly.

I have shot approx. 250 rounds through it and staying within published max loads average velocitys are in the 1,370 fps range for my latest attempts. Spent brass looks great and I am happy. I may back down a little for accuracy but plan to keep the velocity high.

I also installed a Wolf extra power 19# spring. Brass ejects approx 5 feet.

In another thread I read where 357 Sig conversion from 40sw will beat up a gun. The other thread was specific to Browning Hi Power but if it is true for what I thought was a top quality gun then maybe it is true for a Glock.

Is this true? And if a 357Sig will beat up a gun, why?

Any thoughts, or better actual experience.
Thanks, James

[Eagle0711]

I believe that thats the same frame as the Glock 17 or 19. The 9mm has some very hi pressure rounds and will safely fire NATO ammo. I wouldn't think that that the 357 Sig would be any worse. It's .357 bullet as opposed to a .355 bullet. So not much difference, .002. The pressure is whats hard on guns, but you don't have to shoot the hottest loads, even if you did it would probably be ok. I would change the recoil spring regiliously. You could call Glock's Customer Service just to be sure. Best , Lyle

[jtmckinney]

Not sure about the Glock 17 and 19. Unless my info is wrong it is the same frame as the Glock 22. I think below the slide will interchange.

357 Sig is .355 bullets, same as 9mm, not .357 bullets.

I will also add that the bullets I load have all been HDY HP/XTP 147 grain.

I doute that Glock will have anything to offer once I tell them that I changed to another caliber with an aftermarket barrel.

Thanks for the reply.
James

[azredhawk44]

Aftermarket glock barrels tend to have fully supported chambers.

You could have gotten one in .40, and probably been better off critter-wise, than with the .357sig.

Heavy (greater than 125gr) bullets in the 357sig have a tendency to compress the bullet into the case or otherwise not grip it properly at the mouth.

Since the .40 is a straight case, that isn't a problem.

The .40 also allows you to go up to 180gr, though 180's at max pressure are VERY temperamental about OAL and bullet setback.

Given a choice to shoot a toothy-hairy critter with a .357sig @ 147gr or a .40 @ 180gr, I'd take the 180.

ETA: But to answer your question, no the .357sig will not beat up a Glock.

[testuser]

Glock 9mm, .357 Sig and .40 S&W use the same frame. You could fire 9mm in your pistol if you change the slide and bought new magazines. The Glock 20 and Glock 21 also share the same frame and can be converted in the same manner.

1350 fps for a 147 grain bullet in the .357 Sig is quite high. What is your load exactly? Are you using a standard length barrel?

Firing hot loads, even if they're under published max is going to cause more wear and tear on your weapon. You just can't get something for nothing.

That said, it's not like your weapon is going to self destruct. You're just going to need to change recoil springs sooner and if you shoot a lot you'll be replacing parts more frequently. I doubt it will "eat your gun", just more a little more wear and tear.

If you want a greater safety margin, then you may want to consider a different caliber and a stronger pistol.

The 10mm is great for hunting. I generally load it with a 10.2 grains of Blue Dot under a 180 grain bullet for around 1,200 fps. That's either 5% to 8% below max depending on which reloading manual I'm reading. I'm also getting excellent accuracy.

The 10mm will also allow you to use a 200 grain bullet traveling between 1100 fps - 1200 fps for excellent penetration. If you're looking for energy, then 155 grain bullets can reach 1450 fps with Blue Dot or AA#7 according to my Hornady reloading manual.

[precision_shooter]

Like other have said, if you shoot max pressure loads all the time every time then parts are going to wear out faster, but they are not unsafe to fire with full pressure loads.

[jtmckinney]

azredhawk44 I agree about the 40 at 180 grain being better critter wise. I am a careful reloader and had been made aware about how care is needed with the 40sw at max loads.

I had one bullet compressed into the case with the first batch I loaded but havn't had that problem since. I havn't been applying any crimp but may start. This was also new brass so we will see when I start re-clycling brass.

I posted for a non-compensated barrel in 40sw for it when Range Ruger offered a 357 Sig barrel, I thought what the heck and it is being fun. I also plan to get a new 40sw barrel for it when I get a few extra dollars. I already have dies, brass and 180 grrain HP/XTB bullets, Hopefully I will get to do enough hunting in the next year to give actual experience comparison between the two.

Thanks for the reply, James

[jtmckinney]

The load is 8 grains 800X, OAL 1.400, 147 grain HDY HP/XTP.

Barrel is standard length for a Glock 24 which has a 6 inch factory length barrel. All the load data I could find was for a 4" barrel. and 8 grains 800X is the max load in the Lyman 3th edition pistol and revolver handbook and you are right the velocity listed was 1225 fps.

I also tried 10.5 grains AA#9 which I thought would give me better velocity being a slower burning powder with the 6" barrel but didn't, average velocity was 1,291 fps.

7.6 Grains 800X got me 1330 fps and the velocity deviation was a lot better. MAD .090% and SD 1.10% with a 10 shot string.

I am new to using a chronograph and still learning the basics. I am also brand new to loading for a pistol (only loaded for my sporting rifles) and still have a lot to learn both about how to load for and shoot them.

Thanks, James

[testuser]

Hi James,

Oh, yeah, you're fine. I checked out IMR's site and max load for a 147 grain XTP is 9.0 grains of 800X. Sounds like a good load to me!

I've always avoided 800X because I heard it doesn't meter well. What's your experience?

I have to be careful with my Blue Dot loads. Nominal charge weight for my 10mm load is 10.2 grains for my, but it will actually throw between 10.0 and 10.5 grains. (That's actually not too bad. Ball powders on the other hand will throw plus or minus .1 grain for me.)

I started off loading rifles as well and now load nothing but pistol. (Loading for 8 different pistol cartridges now.) I found I had to be much more careful when using my powder measure for pistol loads, since small variations can be the difference between safe and unsafe.

Sounds like all is well. Enjoy your Glock. I don't think you have anything to worry about.

[jtmckinney]

"testuser" I also thought I was fine but you know how worrying these intenet forums can be.

I recently started using the cheap Lee powder measure, dumping into my RCBS 5-0-2 scale and then topping off with a RCBS powder trickler. I should have bought a powder trickler years ago. It has been several weeks but I do remember 800X not metering that well in my measure.

If I get to shooting as much as some of the "pros" on this forum then maybe I will need to start dumping straight into the case but I am not there yet.

I have not given up on AA#9 and definately plan on tweeking both powders for max performance with velocity AND accuracy in mind. When I find this I will load up a bunch and them find a load that is less expensive and easier on my gun for range and practice use.

10mm also interest me. I like how light the Glock is and a 10mm Glock with an extended barrel might be what I put together next.

Thanks, James

[sdj]

I have found it harder on the budget than on the gun. :-D

[JohnKSa]

As I recall, Beretta refused to come out with a .357SIG conversion for their popular 96 pistols and went on record as saying that the conversion was a bad idea because the higher slide velocity would result in unacceptably short service life if applied to the 96 pistol.

Based on that I would say that converting a .40S&W pistol to .357SIG will likely result in more wear and probably shortened service life. Just how much more wear and how much shorter would depend on a lot of things. It may be a non-issue for some designs but Beretta apparently didn't feel that it would be a non-issue in the Beretta 96.

I'm pretty sure I've also seen a caution somewhere about doing a .357SIG conversion on the older .40S&W Glocks that lack the second pin on the frame above the trigger.

[cougar gt-e]

The 9mm has some very hi pressure rounds and will safely fire NATO ammo. I wouldn't think that that the 357 Sig would be any worse.


The 357sig is 40,000 psi and the 9mm is 34,000.

[jtmckinney]

JohnKsa, or others that may know.

When you said "I'm pretty sure I've also seen a caution somewhere about doing a .357SIG conversion on the older .40S&W Glocks that lack the second pin on the frame above the trigger."

Please see attached picture of the trigger area. It does have 2 pins, does this mean that my Glock may not be one of the earliest versions? Serial # is BMD3xxUS if that means anything. Serial # frame, slide, original barrel and box all match.

I know that the 357 Sig is a higher pressure cartridge than the 40sw but the bullet energy is almost the same. Maybe I am making it more simple than it is but I would think the only time slide velocity would matter would be when it hit the stop at the end of the back stroke. If case ejection is an indicator with the stock spring spent cases would eject approx 8 to 10 feet with factory loaded white box 125 grain GR.JHP ammo. All of my reloads with 147 grain bullets, extra power 19# spring and probably higher velocity are ejecting 4 to 5 feet.

Again I think I am ok. More force and impact will shorten the like of anything but I do not get the feeling of a destructive force when I am shooting it.

Thanks for the replys,
James

[ET.]

Higher pressures of the 357sig might wear out the springs a little early , but I can't see it doing any more damage to the gun than the original ammo would have.

[Manco]

Some designs, even with guns of high quality manufacture, are not as well suited to .357 SIG, but Glocks and M&Ps that are originally chambered in .40 S&W, for example, shouldn't have a problem. They may wear slightly faster, but a heavier spring may help in that regard--use whatever the factory spring weight is in the .357 SIG models if you really want to be prudent.

[AKsRul.e]

Quote:
"The 9mm has some very hi pressure rounds and will safely fire NATO ammo. I wouldn't think that that the 357 Sig would be any worse. "
---
"The 357sig is 40,000 psi and the 9mm is 34,000. " Unquote:

Because the cases ,barrels , and slides of the two cartridges are Different this
is NOT a meaningful comparison.

Every Cartridge /gun combo has a different "safe" pressure level. :)

[JohnKSa]

Please see attached picture of the trigger area. It does have 2 pins, does this mean that my Glock may not be one of the earliest versions? Assuming the caution was accurate then it does not apply to your pistol.I know that the 357 Sig is a higher pressure cartridge than the 40sw but the bullet energy is almost the same. Maybe I am making it more simple than it is but I would think the only time slide velocity would matter would be when it hit the stop at the end of the back stroke.Recoil is dependent on momentum, that is, the product of the mass of the projectile and the velocity of the projectile. The velocity of the slide (for a given mass barrel/slide combination) will be higher for higher muzzle momentums.

The slide velocity is important at the very beginning of slide rearward movement when the barrel is stripped away from the slide and stopped. Before that point the barrel and slide are moving as a unit and so the faster the slide velocity is, the faster the barrel is going. The higher speed of the barrel means more energy must be absorbed by the barrel and by the parts of the gun that bring the barrel to a stop.

The slide velocity is also important at the end of the stroke but by that point it's been decelerated by the recoil spring.

[Manco]

Recoil is dependent on momentum, that is, the product of the mass of the projectile and the velocity of the projectile. The velocity of the slide (for a given mass barrel/slide combination) will be higher for higher muzzle momentums.

That's a good observation. Interestingly, since .40 S&W generally has higher muzzle momentum, then all else being equal the slide would have a higher velocity when shooting this caliber than .357 SIG. And since .357 SIG barrels are heavier than .40 S&W barrels in many designs, the slide velocity when shooting .357 SIG would theoretically be lower still.

[jtmckinney]

Thanks for the replys and info.

I will keep loading for it and shoot it as a 357 Sig. I may buy a 40sw non-compensated berrel for it in the future with fully suported case head, we will see.

Once again Thanks!
James

[Lemmon]

If you plan to use a 40 S&W Glock for the 357 Sig, be sure to use a 3rd Generation or later Glock. The 1st Generation 40 S&W Glock was not designed for the pressure that is generated by the 357 Sig. I got this information from Glock the hard way after needing to replace my 1st Generation Glock 22 frame. The Glock Tech told me that the 3rd generation is more able to handle the increased pressure of the 357 Sig.

Lemmon

[aryfrosty]

I bought a G-27 .40cal about 3 years ago and then decided to change it to .357 by way of an aftermarket barrel from Lone Wolf. I also went through and put new internal parts in. This little gun has been such a great shooter that I recently bought a G-32. I also changed it to an LWD barrel. I don't reload but with 125gr bullets the two are really good shooters and easy to manage while being fired. The 32 has new internal parts as well.

[JohnKSa]

Interestingly, since .40 S&W generally has higher muzzle momentum, then all else being equal the slide would have a higher velocity when shooting this caliber than .357 SIG. And since .357 SIG barrels are heavier than .40 S&W barrels in many designs, the slide velocity when shooting .357 SIG would theoretically be lower still.I do not find any flaws in your mathematics nor in your reasoning.

I did an ammo survey for several calibers including the .40S&W and the .357SIG that involved data from all the manufacturers for which I could find online data awhile back. I went back and looked at them and it seems that the .40S&W has a higher average muzzle momentum than the .357SIG. In addition, the maximum muzzle momentum out of all the loadings in both calibers was also turned in by a .40S&W load.

On the surface it seems that the .357SIG should have lower slide velocity than the .40S&W even though we have a couple of data points (Beretta's statement & the caution about converting 2 pin Glock .40S&W pistols) that suggest otherwise.

I do not have an explanation for the contradiction.

[jtmckinney]

I have only become interested in pistols and how they operate for less than a year and still have lots to learn so what I am saying next is on the outer edge of my knowledge as to how pistols work.

I was under the impression that blowback pistols (I am pretty certain that Glocks are blowback operated) did not rely on muzzel momentum alone if at all but used the pressure remaining in the chamber when the brass contracts and releases from the barrel to start the slide movement to the rear and then slide momentum completes the cycle. The case becomes a piston applying rearward force to the slide..

357 Sig is a higher pressure cartridge but I am not sure that means the brass would release to operate the slide at a higher pressure. 357 Sig probably does loose some holding surface to the 40sw because of the sholder and smaller neck.

Maybe I am over my head but I find this interesting and plan to purchase a couple of books on gunsmithing in the next couple weeks that may make my understanding better.

Thanks,
James

[greyeyezz]

Your SN indicates a GEN2 pistol. Call Glock about a frame upgrade, or shoot till breaks, send in, repeat.

[32 Magnum]

I own a SIGARMS PRO 2340 Blue Line, came from factory with .40 S&W barrel. I purchased a SIG factory .357 SIG barrel, which is a dead drop-in installation. I had reason to call SIGARMS in Exeter NH concerning repairs to another SIG pistol and asked the Tech about changing the recoil spring when using the .357 barrel/ammo. He told me that the spring that came with the .40 set-up was more than adequate to handle the .357 loads and that is what they do for factory .357s.

[JohnKSa]

I was under the impression that blowback pistols (I am pretty certain that Glocks are blowback operated) did not rely on muzzel momentum alone if at all but used the pressure remaining in the chamber when the brass contracts and releases from the barrel to start the slide movement to the rear and then slide momentum completes the cycle. The case becomes a piston applying rearward force to the slide..Frankly, I haven't done much study on how blowback pistols work, but what you say sounds reasonable.

However, all Glocks generally available in the U.S., and most other centerfire autopistols in calibers more potent than .380ACP/9mm Makarov employ some sort of a locked breech system, they don't operate on the blowback principle.

The most common form of locked breech system in centerfire autopistols is the Browning (or modified Browning) tilting barrel that locks the barrel to the slide when the gun is in battery. They are recoil operated which means that they operate based on the principle of conservation of momentum. Glocks (with the possible exception of the .380ACP Glocks which are not generally available in the U.S.) use this system.

[jtmckinney]

To all that answered or checked in, thanks for your interest.

I just ordered "Gunsmithing:Pistols & Revolvers" by Patrick Sweeny. It looked like it had a full chapter on how pistols operate and hopefully will answer any questions or misconseptions I may have as to how pistols operate.

If I am shortening the life of this pistol, so be it. I don't think so. Also I am starting with a pistol several years old with an unknown history. This is all fun stuff for me and hopefully I can keep it that way.

Once again, Thanks!
james

[Manco]

On the surface it seems that the .357SIG should have lower slide velocity than the .40S&W even though we have a couple of data points (Beretta's statement & the caution about converting 2 pin Glock .40S&W pistols) that suggest otherwise.

I do not have an explanation for the contradiction.

I don't, either, and it sure makes me wonder about the almost universally perceived "snappiness" of .40 S&W vis-à-vis the perceived "push" of .45 ACP, too. Often there are significant differences between the weapons used, but people have reported the same phenomenon when similar weapons are used for both calibers. When shooting revolvers, I can understand how one may be able to feel the differences in acceleration and peak force between two calibers, but autoloaders are rather different.

Most of the recoil impulse one feels when shooting a typical short-recoil-operated autoloader is transferred via the frame when the barrel engages the locking block and then when the slide hits the end of its travel; most of the rest of the impulse is imparted through compressing the recoil spring, I believe. The whole time this is happening, the momentum of the slide is what determines how much recoil impulse is going to be imparted, and given slides of approximately equal mass, momentum simply boils down to slide's velocity. Since 230 grain .45 ACP loads generally have more momentum than .40 S&W loads of any mass, the slide should be moving faster and hitting harder overall with .45 ACP, and with nothing to make .40 S&W feel more "snappy." Unless I've missed something major here, the only areas where the shooter could perceive the differences between the internal ballistics (i.e. what goes on inside the cartridge and barrel during a shot) are the friction (and also the "stiction") between the slide and frame, and the initial compressing of the recoil spring--both only while the bullet is still inside the barrel, of course. Something must be going on, I presume, but it's kind of hard to believe that any differences in "snappiness" between .40 S&W and .45 ACP could so clearly be perceived though a little bit of friction and a spring, and that such a perception would not be overwhelmed by the relatively large recoil impulse that follows.

I was under the impression that blowback pistols (I am pretty certain that Glocks are blowback operated)

Except for the models chambered in .380 ACP, Glocks operate on the short recoil principle.

did not rely on muzzel momentum alone if at all but used the pressure remaining in the chamber when the brass contracts and releases from the barrel to start the slide movement to the rear and then slide momentum completes the cycle. The case becomes a piston applying rearward force to the slide..

There are a number of different blowback-type operating systems, but in a simple blowback system the barrel, which is generally fixed to the frame, and slide are only held together by spring pressure. As soon as the pistol is fired, both the bullet and cartridge case are pushed apart in opposite directions by gas pressure. The bullet is free to move, but the case has to push against the relatively heavy slide plus the pressure of the recoil spring, which together slow the case down and keep it from coming out of the chamber so far that it would explode (although it does move some) because the gas is still pushing against the bullet, generating pressure. This should--by basic design rather than any intelligence on the part of the gun--buy enough time for the bullet to clear the muzzle, at which time the pressure will rapidly drop to safe levels for the case to be extracted and ejected. The case and slide are moving the whole time, in case you're wondering--they don't know what's going on, they just have to move slowly enough in order to avoid an explosion, that's all. The slide should have enough momentum to cycle the rest of the action.

357 Sig is a higher pressure cartridge but I am not sure that means the brass would release to operate the slide at a higher pressure.

The high pressure and power of .357 SIG means that the case is blown back really hard, and therefore would require a heavier slide than you could get away with when using a more complex operating principle, such as short recoil. Generally anything more powerful than .380 ACP or 9x18mm Makarov uses something other than simple blowback for this reason, although there are some exceptions.

357 Sig probably does loose some holding surface to the 40sw because of the sholder and smaller neck.

I don't think you would want to rely on the friction (and stiction) of the case against the chamber to prevent the case from shooting out too fast and exploding--the inertia of the slide is much more reliable.

Maybe I am over my head but I find this interesting and plan to purchase a couple of books on gunsmithing in the next couple weeks that may make my understanding better.

Go for it, and then tell me whether I got anything wrong here. ;)