[twpbaseball10]

Has anyone every hear or seen this? i was watching dallas swat on tv and he was showing his sig pistol and showed the bullets. it was a .40 cal casing that was necked down to accept a 9mm bullet. What caliber round is this?

 

[twpbaseball10]

also, could you use this in any .40 cal gun or do u have to do modifications? what guns could you use with this caliber?

 

[kaytod]

357 SIG. is a 40 S&W necked to .355/9mm it is intended to give 357 mag ballistics in an autoloader. Which with light bullets is in the ballpark. Based on the 40 it can be had in double stack magazines. I am unsure of how many conversion kits are out there for the various manufacturers, but I'm sure you could find numeous ones.

 

[Combat Diver]

If you have a .40 S&W pistol then all you would need is a new .357 SIG barrel. Conversion are popular in the Glock/SIG platforms.

CD

 

[pme166]

Love the round. The 357 SIG is a lot of fun to blast with. I have a 229 sport and when I just want to plink and blast it is the round to go with. The SIG is great becasue the high pressure gas works the comp perfectly. My 229 sport will actually recoil down with my 90 grn "screamers" that are made with max loads of AA9.

 

[crazydave]

My Glock 22 loves the .357Sig bbl - I drop it in and go to town....

 

[Big Bore]

Most semis in 40 can easily be converted to .357 SIG with just a new barrel. HK USPC can be converted easily as can the P2K, P2KSK, P30, P30L, but NOT the USP.
NOTE: The .357 SIG is NOT just a necked down .40. Since the .357 SIG actually headspaces on the case mouth instead of the shoulder (like it should have) if you neck down the .40 S&W case the case will be too short to headspace properly on the mouth. So, one cannot simply take a .490 S&W case, run it through the .357 SIG sizing die and come out with a perfectly formed .357 SIG case.
Other than that, a new barrel, some ammo, and you are good to go.
This usually also works when going from a .357 SIG to .40 S&W. All you need is a new barrel, usually.

 

[Ko Improbable]

Most semis in 40 can easily be converted to .357 SIG with just a new barrel. HK USPC can be converted easily as can the P2K, P2KSK, P30, P30L, but NOT the USP.
NOTE: The .357 SIG is NOT just a necked down .40. Since the .357 SIG actually headspaces on the case mouth instead of the shoulder (like it should have) if you neck down the .40 S&W case the case will be too short to headspace properly on the mouth. So, one cannot simply take a .490 S&W case, run it through the .357 SIG sizing die and come out with a perfectly formed .357 SIG case.
Other than that, a new barrel, some ammo, and you are good to go.
This usually also works when going from a .357 SIG to .40 S&W. All you need is a new barrel, usually.

And, you also can't trim a 10mm case down and size it down to .357 Sig. 10mm uses a large pistol primer, so all of your load data would be off. It's a high pressure cartridge already, so that'd make me really nervous.