The problem you will run into is the bolt face diameter. The 7mm Rem Mag has a magnum bolt face diameter where as the .270 has the standard .30-06 bolt face diameter. You would have to replace the bolt with a different bolt for this to work. Its not a huge deal, especially if your smith is gonna lap the lugs on the new bolt and of course the new barrel would be headspaced to the new bolt, so that would work. Just another extra cost to consider.
The 270 will give up some performance, but will be more pleasant to shoot.