gas-operated infantry rifle … His early efforts showed a great deal of promise, and Garand would eventually patent his “Semiautomatic, Caliber .30, M1 Rifle” during 1932. However ...

22) by Bob Seijas about M1 Garand rifles produced by Springfield Armory. I agree that rifle #6084405 was the last one assembled, but I question rifle #6100499 being the highest serial number used.