What 357 Sig caliber to buy?

[WrongHanded]

Glock has separate magazines for 357 so converting a G22 or G23 may require a new magazine.

I do know that my G23 mags will run .357 Sig without a hiccup. Where or not .40 will run from G32 mags, I don't know.

 

[whatnickname]

I do know that my G23 mags will run .357 Sig without a hiccup. Where or not .40 will run from G32 mags, I don't know.

Always wondered if this was just a Glock ploy to sell more magazines. I have read that there is a minor difference in the follower between the 357 and the 40. Who knows.

 

[AK103K]

This is a smoking hot round guys. I shoot mine occasionally but mostly keep them stashed around the house loaded and ready to go. They are a technical challenge to reload. The flash holes and much smaller in diameter on a good many brands of brass. These will require smaller diameter decapping pin. The pressure is so darn high that some of my once fired brass has been rendered unusable after just one reloading due to way over-size primer pockets.

Ive loaded quite a bit 357SIG and its really no harder to load for than anything else. One extra step if you use a 40S&W carbide sizer as your first step, then reload as usual.

Just watch you dont get any 40 cases's mixed in, as they will come out of the 357 die as a 357SIG and will function and fire. You simply end up with a neck thats a couple of thousandths short. Its also been my understanding that the brass is made/spec'd different between the calibers and the 357SIG brass is slightly different. Ive had it happen, and only found the 40 marked, 357SIG cases down the road when I was reloading them again. Wouldnt have known otherwise if I hadnt seen the headstamp either.

If youre getting unusable once fired (or 10 times fired for that matter) brass, something is very wrong and you need to check that out. That shouldnt be happening.


I was big into 357SIG back in the late 90's, early 2000's. All but one of my guns were SIG's, P226's, P229's, and a P239. The oddball was a Glock 31. The SIG's had no troubles with the round. My 31 was beating itself to death. The locking block was battering the underside of the slide heavily, and showed no signs of letting up. I put a LWS 40-9 9mm conversion barrel in it and that was the last 357SIG I shot out of it.

I had 40 conversion barrels for the SIG's (226/229) and the mags worked fine with either. The P239 came with 357SIG specific mags and they would not take a 40 round due to the offset at the neck. The later P239 mags were marked for both rounds and both would work with them. Not an issue if your gun is 357SIG, but if you pick up spare mags used, make sure they are marked for both if youre using 40.

 

[WrongHanded]

Always wondered if this was just a Glock ploy to sell more magazines. I have read that there is a minor difference in the follower between the 357 and the 40. Who knows.

Along with my recently purchased G22, I bought three additional .357 Sig mags (same price as .40s, so why not). Upon casual inspection, I didn't notice a difference in the followers (other than the caliber designation). However, all my mags are Gen4, and after looking around the web, it seems the older .40 magazines had a different follower than my mags do. So perhaps there once was a difference, in previous generations.

If I encounter a lack of compatibility between cartridges and magazines once I get a .357 Sig barrel for the G22, I'll be sure to post it up.

 

[Chuck R.]

I've got an HK P2000 and a SIG 226, both of which started as .40s and have been converted.

I load 357S using a set of Dillon carbide dies, so I skip the extra sizing step. I just use a powder that fills most of the case; Blue Dot, Long Shot, AA7 and select a bullet with a long bearing surface, short nose and I've never had an issue. I can easily duplicate factory loads with Long Shot without any pressure signs.

 

[Trey Veston]

BTW, my Glock G35 Gen 4 .40 S&W mags are marked ".40" and my S&W M&P40C mags are marked ".357/.40".

 

[whatnickname]

Ive loaded quite a bit 357SIG and its really no harder to load for than anything else. One extra step if you use a 40S&W carbide sizer as your first step, then reload as usual.

Just watch you dont get any 40 cases's mixed in, as they will come out of the 357 die as a 357SIG and will function and fire. You simply end up with a neck thats a couple of thousandths short. Its also been my understanding that the brass is made/spec'd different between the calibers and the 357SIG brass is slightly different. Ive had it happen, and only found the 40 marked, 357SIG cases down the road when I was reloading them again. Wouldnt have known otherwise if I hadnt seen the headstamp either.

If youre getting unusable once fired (or 10 times fired for that matter) brass, something is very wrong and you need to check that out. That shouldnt be happening.


I was big into 357SIG back in the late 90's, early 2000's. All but one of my guns were SIG's, P226's, P229's, and a P239. The oddball was a Glock 31. The SIG's had no troubles with the round. My 31 was beating itself to death. The locking block was battering the underside of the slide heavily, and showed no signs of letting up. I put a LWS 40-9 9mm conversion barrel in it and that was the last 357SIG I shot out of it.

I had 40 conversion barrels for the SIG's (226/229) and the mags worked fine with either. The P239 came with 357SIG specific mags and they would not take a 40 round due to the offset at the neck. The later P239 mags were marked for both rounds and both would work with them. Not an issue if your gun is 357SIG, but if you pick up spare mags used, make sure they are marked for both if youre using 40.

I have no idea why you have enjoyed better success with your 357 brass than I have with mine. I invested in a primer pocket gauge ( Go / No-Go ) from Brownells and found that some once fired factory brass, Speer ammo fired in my pistol, had primer pockets that were too loose. These were darn hot factory rounds. Since checking my primer pockets I’ve had no issues. I also found out the hard way that a good many of the flash holes, again in Speer brass, were too small to accommodate a standard size decapping pin. Called Speer and basically got a smart-ass answer. They warned emphatically not to try enlarging their flash holes for safety reasons. A good many folks on THR called BS on that when I posted it. Called Starline. They knew about the issue and indicated that the small flash hole was supposedly a move to get better ignition. Hornady manufacturing division had never heard about the small flash hole issue. RCBS knew all about it. Bought one of their resizing dies and had no further problems. I tend to reload this round toward the upper end of the performance curve. I’ve had no additional problems since I started using the RCBS die and checking my primer pockets.

 

[whatnickname]

Plus it’s the gun the Secret Service carries.

Well now you’ve done it! They’re the Secret Service. Now that you’ve told the world what they carry it’s not a secret any more.

 

[AK103K]

I have no idea why you have enjoyed better success with your 357 brass than I have with mine. I invested in a primer pocket gauge ( Go / No-Go ) from Brownells and found that some once fired factory brass, Speer ammo fired in my pistol, had primer pockets that were too loose. These were darn hot factory rounds. Since checking my primer pockets I’ve had no issues. I also found out the hard way that a good many of the flash holes, again in Speer brass, were too small to accommodate a standard size decapping pin. Called Speer and basically got a smart-ass answer. They warned emphatically not to try enlarging their flash holes for safety reasons. A good many folks on THR called BS on that when I posted it. Called Starline. They knew about the issue and indicated that the small flash hole was supposedly a move to get better ignition. Hornady manufacturing division had never heard about the small flash hole issue. RCBS knew all about it. Bought one of their resizing dies and had no further problems. I tend to reload this round toward the upper end of the performance curve. I’ve had no additional problems since I started using the RCBS die and checking my primer pockets.

When I first got into the round, I bought a couple of cases of the Speer Lawman ammo for practice, as it was supposed to mimic their Gold Dots. I also bought a case of their Gold Dots. Back then, 357SIG was still fairly cheap, and the exact same price as 40 S&W when bought by the case. Right around $250/1000 for the Lawman.

I really didnt reload for it initially, mainly due to the basically caliber-specific 357SIG bullets being expensive, and I was only paying a dollar more a 50 round box for factory ammo by the case. Once the factory ammo took off, and it became more economical to load it, I switched over to doing that. I made out like a bandit when I decided to get out of the caliber when things really got silly, and more than doubled my money on the unopened cases of ammo when I sold them.

You cant normally use most 9mm bullets with the round when you reload, as the shape of the bullet wont allow proper OAL. The closest "9mm" bullet that comes close to the shape of the 357SIG bullet, is the 147 grain bullet. The shape is about the same, with the ogive more forward. I never had good luck with accuracy loading the 147's in the 357SIG though.

Most of my all of my brass was Speer, from the Lawman that Id shot. Never had an issue with it. Never noticed there was a problem with the primer pockets, ot that the flash holes were undersized They all decapped and reprimed without issue. At least I never noticed that something might be amiss. The same cases were reloaded a good number of times too.

Ive been using Hornady dies for a long time now and prefer them over the RCBS. Maybe their decapping pins are smaller, and the flash holes werent an issue.

The load I was using at the time, was a mimic of the factory loading. A 125 grain bullet over 13.0 grains of AA #9, which was the recommended load at the time. It was a compressed load too, which helped with the neck tension issues that the round can have. With the compressed load, there was no chance of bullet setback.

I havent been shooting/using 357SIG for about a decade now. Are you still seeing the smaller flash holes in the Speer brass?


I just remembered while writing this that I pulled down a box of 50 357SIG that Id found a week or two back in the cabinet, that Id loaded with 147 grain Gold Dots back around 2007. The cases were still in the trash bin just now, and I just decapped them using a set of Hornady 45acp dies. Both rounds I grabbed decapped and felt normal doing so.

Looks like I had some Federal brass in the mix as well. The 9mm was in the trash too and just there for comparison. The Federal flash hole looks like it "might" be a tad larger, but the 9mm and Speer case look the same to me. And actually, they all look pretty close.

The only thing that looks a little weird with the Speer case is, the flash hole almost looks like its "rolled out" a little around the edges. So maybe back when it was first reloaded, the flash hole was slightly smaller, and the decapping pin rolled it out as it went through. Dont know. As I said before, I never noticed anything wrong when I was loading them and they all sized up and decapped without issue, and all those cases were reloaded and shot, numerous times, so if the FH size was "something", it didnt seem to matter when I shot them.

 

[whatnickname]

When I first got into the round, I bought a couple of cases of the Speer Lawman ammo for practice, as it was supposed to mimic their Gold Dots. I also bought a case of their Gold Dots. Back then, 357SIG was still fairly cheap, and the exact same price as 40 S&W when bought by the case. Right around $250/1000 for the Lawman.

I really didnt reload for it initially, mainly due to the basically caliber-specific 357SIG bullets being expensive, and I was only paying a dollar more a 50 round box for factory ammo by the case. Once the factory ammo took off, and it became more economical to load it, I switched over to doing that. I made out like a bandit when I decided to get out of the caliber when things really got silly, and more than doubled my money on the unopened cases of ammo when I sold them.

You cant normally use most 9mm bullets with the round when you reload, as the shape of the bullet wont allow proper OAL. The closest "9mm" bullet that comes close to the shape of the 357SIG bullet, is the 147 grain bullet. The shape is about the same, with the ogive more forward. I never had good luck with accuracy loading the 147's in the 357SIG though.

Most of my all of my brass was Speer, from the Lawman that Id shot. Never had an issue with it. Never noticed there was a problem with the primer pockets, ot that the flash holes were undersized They all decapped and reprimed without issue. At least I never noticed that something might be amiss. The same cases were reloaded a good number of times too.

Ive been using Hornady dies for a long time now and prefer them over the RCBS. Maybe their decapping pins are smaller, and the flash holes werent an issue.

The load I was using at the time, was a mimic of the factory loading. A 125 grain bullet over 13.0 grains of AA #9, which was the recommended load at the time. It was a compressed load too, which helped with the neck tension issues that the round can have. With the compressed load, there was no chance of bullet setback.

I havent been shooting/using 357SIG for about a decade now. Are you still seeing the smaller flash holes in the Speer brass?


I just remembered while writing this that I pulled down a box of 50 357SIG that Id found a week or two back in the cabinet, that Id loaded with 147 grain Gold Dots back around 2007. The cases were still in the trash bin just now, and I just decapped them using a set of Hornady 45acp dies. Both rounds I grabbed decapped and felt normal doing so.

Looks like I had some Federal brass in the mix as well. The 9mm was in the trash too and just there for comparison. The Federal flash hole looks like it "might" be a tad larger, but the 9mm and Speer case look the same to me. And actually, they all look pretty close.

The only thing that looks a little weird with the Speer case is, the flash hole almost looks like its "rolled out" a little around the edges. So maybe back when it was first reloaded, the flash hole was slightly smaller, and the decapping pin rolled it out as it went through. Dont know. As I said before, I never noticed anything wrong when I was loading them and they all sized up and decapped without issue, and all those cases were reloaded and shot, numerous times, so if the FH size was "something", it didnt seem to matter when I shot them.
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In my discussions with Starline, the entire small diameter flash hole thing is relatively recent within the past year or two. No one I’ve spoken to really sees any reason for the change and Speer was downright indignant for my even asking. Bet you a nickel they wouldn’t be that way if they were still owned by Vernon Speer. That roll out you’re seeing in the Speer case is likely caused by a smaller diameter flash hole. Like you, I was using Hornady steel dies and got the same thing until I got one that was just a little too small to be swaged and pulled the entire spindle out of the die. That was a royal pain to get off the decapping pin too. And I know what you mean about RCBS. You can tell that they’re no longer owned by Fred Huntington. They had the solution to my problem at a modest price. These days I prefer Dillon dies for my handgun calibers. Didn’t intend on using my progressive press to reload the 357 Sig round. Sounds silly I know but I really enjoy reloading and occasionally opt to reload things like 357 SIG and 38 S&W on a single stage press. Any more when it comes to rifle dies I buy Redding or Forester. I’m especially fond of the Forester Bench Rest seating die. They’re more expensive but I can afford it. You get what you pay for.

I’ve never seen the barrel hood beat the hell out of the underneath side of a slide like yours did to your G31. Wondering if you discussed that with Glock and what their response was?

 

[AK103K]

From what Ive been told by a number of people, the slide battering is fairly common with the Glocks in 40. I dont have one in 40, and the couple Ive looked at didnt seem to have the issue, but my 31 was not doing real well. I actually had to file the burrs off a couple of times.

What kind of amazed me is, my one 17, which had more +P+ 9mm through it (more than the 31 had 357 through it), which is in the same pressure range as the 357SIG, yet it only shows some slight finish wear in the same spot.

Never did call Glock over it, and I really didnt have it very long. Once I came to realize there really wasnt that much of a difference between them, shooting and power-wise, and the cost more than doubled at the time, I sold the 357's off and switched over to 9mm.

 

[whatnickname]

From what Ive been told by a number of people, the slide battering is fairly common with the Glocks in 40. I dont have one in 40, and the couple Ive looked at didnt seem to have the issue, but my 31 was not doing real well. I actually had to file the burrs off a couple of times.

What kind of amazed me is, my one 17, which had more +P+ 9mm through it (more than the 31 had 357 through it), which is in the same pressure range as the 357SIG, yet it only shows some slight finish wear in the same spot.

Never did call Glock over it, and I really didnt have it very long. Once I came to realize there really wasnt that much of a difference between them, shooting and power-wise, and the cost more than doubled at the time, I sold the 357's off and switched over to 9mm.

Good to know. I don’t shoot my G31 & G32 much at all. I’ve got a G22 & G23 which I have shot a good bit but basically reload plated bullets at modest pressure levels for target shooting. Haven’t noticed any issues with the slides on these. Think I will give Glock a call after the first of the year and see what they say. It will be interesting to see whether or not they address this matter openly or get tight lipped about it. I’ve had issues with other manufacturers, like FN, that didn’t want to talk about stuff like this at all. I really appreciate you sharing this information. I’ll let you know what I find out.

 

[M1key]

I load for my G31 with 115/124 XTPs which are what I have most of, then give them a good crimp with the Lee factory crimp die. In addition I add a Wolff 20 pound spring and guide rod. No serious peening to date. I believe Glock Inc changed the locking block configuration at one point to minimize peening. I still acquired a good supply of factory Speer Gold Dots and Winchester JHPs back when our Walmart stocked it years ago.

M

 

[WrongHanded]

If I encounter a lack of compatibility between cartridges and magazines once I get a .357 Sig barrel for the G22, I'll be sure to post it up.

Well I tried some .40 in my '.357 Sig' Glock magazines. That's a big no go.

Upon further inspection it seems the follower is slightly different on the .357 mags, which is to account for some "rails" running down both sides of the magazine interior at the area where a .357 necks down. My assumption is that this is to add some sort of stability.

Anyway, .40 cartridges jam up in the .357 mags (you can load one in the mag okay though). But .357 runs fine in the .40 mags. So, if you want to run both calibers in a Glock, get .40 magazines.

 

[Wildbillz]

Well I tried some .40 in my '.357 Sig' Glock magazines. That's a big no go.

Upon further inspection it seems the follower is slightly different on the .357 mags, which is to account for some "rails" running down both sides of the magazine interior at the area where a .357 necks down. My assumption is that this is to add some sort of stability.

Anyway, .40 cartridges jam up in the .357 mags (you can load one in the mag okay though). But .357 runs fine in the .40 mags. So, if you want to run both calibers in a Glock, get .40 magazines.

Good to know thanks. Local store has used police 40 cal mags on sale for $9.99 ea. May have to pickup a few.

WB

 

[d'zaster]

HK P2000 with stock .40 and .357 barrels. Awesome reliability.

 

[JR24]

Well if you’re buying a Glock 23, you might as well just buy a .357 Sig drop in barrel for the Glock.

If you’re looking for a complete gun, I’d go with a police trade in P226 in .357 Sig. In fact, if you’re not dead set on the Glock 23, I’d probably go with a P226 and a .40 and .357 Sig barrel.

That's what I'd do.