I once met up with a guy local to me who had a Springfield Loaded for sale. Upon inspection of his rifle it had a significant amount of surface rust on the barrel and receiver. It would not pass the tilt test. I asked if he ever cleaned the piston/gas system and I got a deer in the headlights look. Also I asked what kind of ammo he fired through it and he said mostly Hornady Superformance 308 (too hot of a load for the M1A). He wanted $1200 for it and I passed, a couple hundred more and I could buy a new not neglected or abused rifle.
Good luck
Good luck