Have had a couple examples both weapons. The 14 has a gas cut off and the garand does not. You don’t hear of shooters bending or breaking opp rods in a 14. 14s gas port was also closer to the chamber and generated a lot more pressure iirc. Ive never had personally nor heard of issues due to pressure curves causing malfunctions with M1as...and with all the tactical models SA has been pumping out over the last 20 years there are lots of em out there.
Neither are truly good accuracy platforms imho...and the 14 certainly is not any worse than the garand in that respect. Personally i think the way they both anchor in the stock is the main reason...or at least one of them.
I’ve had two heavily acurized m1a platform guns. A springer NM with a Krieger barrel and a 2 lug LRB with a krieger barrel...both bedded in McMillan stocks. Neither would shoot MOA with an optic and if I were being honest they were closer to 2 MOA.
Ive never shot a Garand with an optic BUT I've owned several and shot several more and while never terrible i certainly never found them to be any more accurate than a M1a with irons...though to be honest that's likely the limitation of the shooter (me).
There is also the issue about the .308 being better than the 06
