Can anyone give me a quick rundown on what the differences are going to be between the threading on a Mark V Weatherby (378 size action) and a CZ 550 Magnum (416 Rigby). I know that the CZ will be metric, but not sure about Weatherby. Not sure what the other difference will be.

Essentially what I'm trying to figure out is if I want to take a barrel off of a Mark V and put it on to a CZ 550, are the threads just going to have to be cut off and the barrel set back or can it be rethreaded as is?