.
The last time I checked, JES charges $250 for a rebore.
He also told me that a bbl must have a minimum barrel wall thickness of .125" @ the muzzle AFTER any rebore, or he'll decline the job.
Do the math for a .30cal to .358cal rebore: .358" + .125" + .125" = .608".
IDK if your pre-64 M70 measures more/less than .600" @ the muzzle, but if it's that much or over, you're good to go.
I know that my .30-06 (1992) M70 FW was a non-starter, because it's muzzle OD was .500"
.
