AR and Garands run like a helicopter- they operate best when every thing in motion, is in balance.
Change a single factor of the operation (“hot loads”), and the balance is changed, and needs correction from the other direction.
Too heavy of a recoil spring - the load won’t run in either.
Garands - IMHO - are more likely to fail from the battering of the rifle parts in operation, than from a single load. End result is the same, the lugs may crack, or the bolt may crack the receiver if the gas pressure operating the system is higher than it should be.
Either can be made to operate with hotter loads within reason, but you need to be able balance the input through gas, spring, or buffer management.
Jeff can probably make this simpler, but that’s my 2 cents.
