Warning: Possible totally newbie/dumb question....

How feasible would it be to rechamber a new 6.5 Creedmoor barrel for 260 Rem?

I am trying to find a Savage action for a rifle build and I found a suitable 'donor' rifle that is chambered for 6.5 Creedmoor. It would be a very nice bonus if the barrel could be rechambered for 260 rem.

My ignorant newbie examination of the SAAMI specs for 260 rem versus 6.5 Creedmore seem to indicate that the 6.5 Creedmore chamber is ever so slightly smaller than the 260 rem and therefore (in ignorant newbie logic) it could be rechambered to the ever so slightly larger 260 rem?

Total stupid fantasy?