maybe the only thing you will have to do is to change the barrels and no other work on the railings!
So you will have the chance to reanimate your 7mm Rem in minutes.....
Try the feeding-action of a .358 NM cartridge in your 7mm Rem - if it startes without problems into the chamber-opening you are a true winner.....
(but if not so - some additional work on the railings will be needed....)