BudsGunShop.com - INTERCHANGEABLE BARREL

Only the 40S&W barrel is directly compatible with this XD 357Sig Pistol. You will need the Springfield conversion kit or a 3rd party direct conversion barrel such as Storm Lake's here (Mfr Part: 34110) : brownells.com/handgun-parts/barrel-parts/barrels/springfield-xd-xdm-conversion-barrels-prod42403.aspx --- I had one for mine and it worked great. Just go out and by a couple of 9mm magazines for it and you should have a great running 9mm. FYI recoil spring was never an issue.

normally you can go from a 40 S&W to a .357 sig. because the case size is the same. I don think you can add a 9mm barrel without an lot of other parts in the slide I would call Springfield and ask (309) 944-5631