I have heard of that happening at least once, but I can't think of where I heard it.
As for switching barrels, you would need to:
Turn out old barrel,
Install new one,
Time cycling of the action for proper feeding and ejection,
Index the rifle properly with respect to the gas port,
Set headspace properly,
(Possibly) install new gas cylinder.
I am by no means experienced, but to the best of my knowledge, that is what needs to be done. I'm not sure if a spacer would be needed for the clip recess and guides.
Solution? Get yourself two Garands. Leave one in the original caliber. Send the other one off to have a .308 1-10 twist barrel installed. Fulton Armory does it quite well.
Then shoot and enjoy both.