How does the 700 shoot. If very well then.........
Why not search around for a new sendero type 'new' take off barrel in 300 Win and simply swap barrels skipping the truing, blue printing?
I did that with a super great shooting 338 Win moving up to a 338 RUM. It shoots great. I think I kinda lucked out but for 40 bucks plus 125 install its a fairly inexpensive experiment. And it would be an experiment.
Keep in mind I come from the cheap seat area over here in Idaho.