I HAVE A NM M1A SERIAL #001329--THE BARREL HAS CA 7791362 ON IT WHICH I THINK IS THE DRAWING NUMBER FOR A NM USGI BARREL MADE BY Canadian Arsenal-?-IT ALSO HAS " 6 67C8549 " AFTER THE DRAWING NUMBER--WHAT DOES THAT NUMBER MEAN ? IVE OWNED IT FOR A LONG TIME.BOUGHT IT FROM A SENIOR WHO SAID HE GOT IT IN THE EARLY 70'S. IM JUST LOOKING TO CORRECTLY I.D. THE RIFLE-IT WASNT USED MUCH BY THE PREVIOUS OWNER--IVE NEVER SHOT IT--BUT MAY BRING IT OUT OF RETIREMENT.