I have 1 Savage rifle and I've had 3 barrels on it. Its action can not handle high pressure
from a 300 Savage in 300 Win. I still have it.
The Savage action cannot handle a high pressure round at least in 300 Win Mag. For each barrel change the gunsmith asked me if I would like to change it to a 300 RUM until I told him it was a Savage then he knew that it could not handle the high pressure of the RUM so he put a standard barrel on it for me.
Sorry, but I, too, would be looking for a new gunsmith.
The SAAMI pressures are:
47,000 PSI = .300 Savage
64,000 PSI = .300 Win Mag
65,000 PSI = .300 RUM
So your smith was telling you the rifle was OK in .300 Win Mag at 64,000 PSI but wouldn't handle 47,000 PSI??? And another 1,000 PSI would be dangerous??? What is he smoking?
More likely the problems lay elsewhere, including magazine length and proper feeding. The COL's are:
2.60" = .300 Savage
3.34" = .300 Win Mag
3.60" = .300 RUM
Plus, the feed rails, follower and bolt head would have to be modified to go from a .300 Win Mag to a .300 Savage or RUM. The maximum case diameters are:
.473" = .300 Savage
.532" = .300 Win Mag
.550" = .300 RUM
There is no problem with the Savage and high-pressure cartridges, but, like any rifle, it is harder or impossible to convert to some rifles to use different cartridges depending on the original configuration. You can't convert a short action to use a .30-06 cartridge no matter what you do, nor should you run .45-70 loads designed for a Ruger #1 through a Marlin or Springfield Trapdoor. My Interarms Mark X action is designed for a .30-06-sized case and would need bolt and feed rail work to feed a magnum-sized cartridge, even though there would be no problem with magnum pressures. A .300 RUM may not be able to be converted to .300 Savage due to case head (too big) and feed rail (too wide) issues. And so on...