Is a 9mm barrel conversion even possible in a 226 originally chambered in 357sig?  I know 40 is because the 357 and 40 share the same case head size, but how can the 9mm conversion work in the bigger cal pistols?  Or is it the whole top end that needs to be swapped in order to swap to 9mm?  I like my 357 sigpro 2022 enough that I traded my XD45 for a 226 in 357, now I almost wish that I got the 226 in 9 because of all the milsurp 9mm ammo I see at at my local shop.  I hate having 3 or 4 different handgun calibers, I guess thats 1 reason I went with a 226 in357 so that 357 and 45(kimber) are the only calibers I need to shop for.  And I like the accuracy of the 357( everyone I've owned has been a tackdriver for a service pistol).

Bar Sto makes a conversion barrel to go from 40/357 to 9 mm. It runs around $200. You can only downsize though, you can't make a 9 mm. into a real gun like .357 SIG.

i hear the barsto barrels may require minor fitting to fit properly.  some need to file to fit and others find it fits perfectly as is.  it just depends but i hear that whether or not you get one that fits perfectly or if you have to modify it a bit, they are great barrels to get.  might be a waitng list thoguh.