300wm or 7mm rum new barrel?

[beakus33]

I was getting ready to order a new barrel and i started to wonder if i should change cal.i was going to go with the 300 win.mag that it started out with (savage111).but then i started to play with the 7mm rum idea but dont know if ther will there be feed issues or internal mag.issues.is there any other ghanges besides a bolt face.