That's not a bad idea, but why not just go 6.5x47 Lapua?
The 6.5X47 Lapua case is a dandy, no doubt about it. For a huntin' rig, the small primers work well even in cold weather. The flash holes do need to be opened up for best results.
The 260 case (improved) offers enough extra capacity over the 6.5X47 case to make this a better choice with a 6.5 bullet, IMO. The large primers/flash holes are a no muss deal. And necking up the Lapua 243W case up to 6.5 is a better approach than necking a Lapua 308W down to 6.5. Using a reamer spec'd off the Rem. 260 case is a slam dunk deal, but I prefer Lapua brass when it's available for a project.
The 'smith you use can advise you which dies work best with his reamer...that may make the whole decision a bit easier and cheaper.
When you take some time and look at all the pros and cons of the 6.5's, it's easy to see why the 7's work so well. A plain vanilla 7-08 or 7-08AI is a dandy.
Have fun with your project and good shootin'. -Al