Skimask, it looks like my son’s account was activated/verified so my original post to you looks a LOT like the one he made. :)
Welcome to FR, son. Say hello to all the nice folks who are trying desperately to save our country!
I believe the .40 model can be switched to .357 Sig with just a barrel and magazine swap. That's normally not a big deal but with the recent scarcity of ammo, it might be nice to have that flexibility.