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They are both large frame and 5" barrels. Sure seems like they'd swap in a few seconds. Could there be headspace questions? There also may be outside diameter barrel questions.
From what I understand you cant go from .40 to 9mm.However you can go to .357 sig from .40 with just a barrel switch-Even uses the same magazines.I think FTF has a good selection of barrels included ported and possible threaded.