From what I've been told (by Sig customer service), the 45 takes a wider frame but .380-.40 are the same.I also have the 45 but have not tried the 40 in the 45 slide. I assume it will fit.
I think OP's question was more about the slide, rather than the frame.From what I've been told (by Sig customer service), the 45 takes a wider frame but .380-.40 are the same.
Well, technically, the longer barrels will fit into smaller slides, and will probably work. But the smaller barrels obviously wont hold in a larger slide. For example, for any given caliber, a Full Size barrel will fit into a Compact slide. Of course, it would look ridiculous and use your discretion whether or not you want to shoot it that way. Nevertheless, it is possible to assemble it this way.The 40 and 357 Sig can interchange with a barrel of the same length as the original. The 9 requires a different spring (and barrel od is different, so use it in a 40/357 at your own discretion), but the 45 is a totally different dimension for the FCU and frame. The slides, from compact to subcompact, and full to compact will work within the 9-40 configuration based on the ones I have.
Smaller barrels (e.g. 9mm) will fit into larger slide (e.g. 40SW). Larger barrels wont fit into smaller slides.
Ok, this is what I figured. Forgetting about the .45, which is essentially an entirely different gun (slide/mags/grip). So the .40/.357 barrels have the same circumference (which means the .357 is thicker?), but the the 9mm is smaller around. So:The 40 and 357 Sig can interchange with a barrel of the same length as the original. The 9 requires a different spring (and barrel od is different, so use it in a 40/357 at your own discretion), but the 45 is a totally different dimension for the FCU and frame. The slides, from compact to subcompact, and full to compact will work within the 9-40 configuration based on the ones I have.
Technically correct. But again, use your own discretion. Based on what I've seen here on the forum thus far, this is a debatable topic. Some say that the 9mm barrel in the 40SW/357SIG slide runs, and shoots fine. Others who have tried it say that it causes increased wear, and report decreased accuracy with this configuration. I've also seen someone mentioned problems related to firing pin alignment.Hmmmmmm....
This suggests that the 357sig and 40 Cal-X kits... could be purchased, and a barrel acquired elsewhere, to get the same end result as a 9mm Cal-X kit.
I need to do some shopping...
So the .40/.357 barrels have the same circumference (which means the .357 is thicker?), but the the 9mm is smaller around. So:
- Do the all have the same dimensions in the chamber (in the squared off area). Meaning, will the all lock into the slide the same way in the ejection port? (I guess we need someone who has all 3).
- The 9mm is smaller, so it should fit in the .40/.357 slide, but will the extra space cause any safety or accuracy issues? (Does the P320 even fully lock up at the muzzle/slide hole, or does it all occur at the base end of the barrel).
So, if I got a P320 in .40 S&W, and just bought a .357 barrel and a 9mm barrel, and the corresponding springs**, would everything fit and shoot fine?
I see.Technically correct. But again, use your own discretion. Based on what I've seen here on the forum thus far, this is a debatable topic. Some say that the 9mm barrel in the 40SW/357SIG slide runs, and shoots fine. Others who have tried it say that it causes increased wear, and report decreased accuracy with this configuration. I've also seen someone mentioned problems related to firing pin alignment.
Personally, I would not run it this way.
You would still need a different recoil spring and extractor probably (especially if they made a thicker/heavier 9mm barrel to fit the slide)... .40/.357 is naturally more powerful and will cycle the slide differently (some 9mm loads would be too weak to properly cycle the slide and eject the shell casing)... and the .40/.357 SIG slide has sights "calibrated", front/rear sizes, for the specific caliber of the pistol. Even when I switch to my .357 SIG barrel in my .40 S&W P320C, the POA/POI is different.I see.
Essentially though, Sig could have made this work by standardizing the external dimensions (both tube and chamber) of the barrels for the three calibers and using one universal slide (in Full, Compact, and Sub-C). This would allow caliber changes to simply be done with a new barrel and mags (though the 9mm might be slightly beefier than necessary, closer to a bull barrel). I wonder if there was an engineering reason they didn't do this, or if it was simply about $$.
This seems to make sense, but SIG only offers one OEM RSA for all calibers (except .45) and all slide/frame sizes (except sub-c): https://www.sigsauer.com/store/sig-sauer-p320-recoil-spring-assembly.html. It seems that they believe 9mm/.40/.357 all are close enough in force to use the same spring (and even more surprisingly with both the Full size or Compact). Maybe I'm missing something, but I cant see it.You would still need a different recoil spring and extractor probably (especially if they made a thicker/heavier 9mm barrel to fit the slide)... .40/.357 is naturally more powerful and will cycle the slide differently
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Could we trouble you for some pictures? :huh:For what is worth, I got a P320 Compact in 40sw. Then I added the 357sig and 9mm threaded barrels. The only thing I change out is the barrel. Everything works great. The only issue I've seen is the last round of 9mm can be hard to get into the mag even with a Uplala (spelling) loader. I keep everything well greased too
I also got a SC x-change kit in 40sw. I do the same barrel swap to 9mm and don't have any issues.
I do use only good quality factory ammo. I do not buy low cost reloads that are out there. Most of my ammo is Speer Lawman or Speer Gold Dot. Somethings I get Rem or Federal.
Technically there is a PIO change, but it would be fractions of an inch at 7 yards. Even at 25 yards it would be less than an inch. If fractions of an inch are an issue for your shooting, the P320 is most likely not what you should be shoot ... haha.
Just because it isn't listed online doesn't mean they don't sell it. I'd be confident in saying that to order most smaller parts, you have to call SIG CS.This seems to make sense, but SIG only offers one OEM RSA for all calibers (except .45) and all slide/frame sizes (except sub-c): https://www.sigsauer.com/store/sig-sauer-p320-recoil-spring-assembly.html. It seems that they believe 9mm/.40/.357 all are close enough in force to use the same spring (and even more surprisingly with both the Full size or Compact). Maybe I'm missing something, but I cant see it.