Re: Changing barrels in my Browning Hi Power 9MM
A barrel-only change...No
A variety of pistol platforms will allow you to convert from larger chamberings to 9mm with a barrel change and changing some parts (Glock for example). I know of no others that will let you "step up" to something bigger without changing the slide or breech face modification.
Why?
The base of .40/.357SIG are not the same as that of a 9mm. This typically involves a changed to the extractor, ejector, or possibly the whole slide to accept the larger base and function, feed, extract, eject properly.
You will amost certainly need to change the recoil spring as load variation in the same chambering can require a change, a change in caliber will require a new spring.
If you want a 357 SIG, buy something better suited for that chambering. If you are THAT partial to the HP platform, proper ammo selection and more practice will do more for you than mangling your HP to fit a hotter (not to mention more expensive, harder to find, and smaller mag capacity) round and compromising the reliability and integrity of your gun.