Last time I fired my M1A it filed to eject. I cleaned the gas piston as to Springfield recommendations. The piston has some pitting on the outside and end of piston. Springfield does not say replace piston if pitted. I checked the OD of piston. All measurements where there was no pitting were .497. I measured the area where the pitting is there and are no high spots. If anything it could be 1/5 of a thousandth small. I can’t see that this would cause any problems. I would not want to score the cylinder walls, as this would be well over a $100 fix. I do not want to replace gas piston if not necessary, it is over $50. Any thoughts, thanks.