Ignore Andrewcranky-Physicalist as he is an atheist therefore a compulsive liar. That places his loyalty in question also. That sort of repugnant malice is what makes atheism as stupid as it is evil.
Contact the Marine Corps Records Center in Kansas City, Mo. for full details.
You will need to be the SNM by name, SSAN, date of enlistment, date, and character of discharge, or a power of attorney that allows you to access this non-public record. That is because it includes such as security clearance, decorations, places of duty, etc.
Again, absolutely ignore anything Andrewcranky-Physicalist says as he will deliberately lie to you because he is just plain sadistic and would love to send you on one wild goose chase after another.
Note that he has over 200 more screen names, all of which reveal that he is utterly incapable of telling the truth. Again, if a known atheist says it, realize that it is an outright lie.