I rescued and put back into service a badly rusted pre-64 M-70 in 270, sent it to JES and had it rebored to 338-06, plenty of meat there on that factory barrel to go 338"
It's favorite load features the 210 gr partition at 2800 fps with H-380 powder, it has to be a higher pressure load, although brass holds up nicely, I have no concerns using it in this rebore.
