Depends on what you're doing. 30-06 to 280 is just a new barrel. 30-06 to 300 win mag is new barrel, new bolt face, new feed rails and new extractor.
Don't forget new types of powders, primers, bullets, dies, brushes, patches, jags, rod, bore guide, etc....
With the rifle work and new equipment it gets real expensive And time consuming in a hurry.
