BudsGunShop.com - Fit of 357 barrel

you will have to change the slide, barrel, springs and magazine

357 sig is a 40cal case necked down to a 9mm bullet the chamber/barrel is larger on the 357 sig then on a 9mm, 357 sig is also a much
higher pressure round then 9mm so 9mm doesn't make a good platform to convert to 357 sig

You would have to replace the entire slide, barrel and recoil springs. It's doable just alot more expensive. Hope this helps

Jeff, no, you can do this with a .40S&w to a .357Sig barrel but not from a 9mm Sig. You would need the complete upper/slide. Cheers and stay safe!

you will have to change the slide, barrel, springs and magazine