The problem of some ammunition damaging a Garand is not due to chamber pressure, its due to excessive gas port pressure caused by useof very slow burning powders, that mostly with bullets exceeding 150 grains.
The Garand was originally intended to handle both M1 and M2 Ball but they found it operated best with M2 Ball.
They also went to single base powders almost exclusively for .30-06 Ball before WW2. Single base powders gave a lower gas port pressure, so the gas port was sized for that propellent which made it a hair over sized for the higher port pressure of double base powders. The same situation caused failures of the M16 when excessive gas port pressures over stressed the mechanism.
Some matchgrade 7.62 will cause problems with some FN FAL rifles for the same reasons, excessive gas port pressure causing early opening while the case is still fully expanded and held tight to the chamber walls, causing rims to be bent or torn off by the extractor.
With the Garand its more likely to bend or break the operating rod.