You'll lose even more when the gunsmith cuts 1" off the shank end to rethread it.
Then you'll have to get a Sako-type extractor installed in the push-feed boltface.
A Sako extractor??? WTF is with that? Cut 1" off the shank??? WTF?
It don't have to be cut and it could be threaded satisfactorily although it may not look very pretty. Is the action already a magnum? If not then you need a new bolt. Don't know of anyone who would do a Sako conversion on a push feed model 70. In the long run, you are always out a bunch of money using a takeoff barrel in a project. Buy a good barrel, not a ER Shaw