If you dont have any long action firearms in your collection, then instead of the 6.5x47 lapua you could consider a Creedmore. Lapua makes small primer pocket brass for it. You have a bit more case capacity then your father in laws x47 and could shoot the 140gr bullets well. Plus you dont need to purchase an action.
You could also build a 260rem (theres lapua brass for that too). this link has been posted a few times on the forum but It might help you with your decision.
http://demigodllc.com/articles/6.5-s...6.5-creedmoor/