One of my 9.3x62's is a rebore/rechamber of an FN 30-06 that Cliff LaBounty did some years ago. Clearwater Reboring bought Cliff's old business. Cliff did fine work as I have two other rebores/rechambers of his, a 338-06 and a 35 Whelen. At the time cost was much less than a re-barrel and blue. All are very smooth and accurate. I load the 250 gr X to 2650 fps in my 9.3's and used that load in Africa 6 years ago with great success. I would not bother with the 9.3x64 as brass is still a hassle I believe.
On barrel diameter, my Whelen rebore measures .555" at the muzzle, same as my factory Ruger 35 Whelen. I recall Cliff wanted 10 thousandths a side at the muzzle.
