Form 2A/B The 1st milled receiver comprised of steel forging. It went into output in 1951 and output ended in 1957. The sort 2A has a particular socketed metal "boot" connecting the butt stock into the receiver plus the milled lightening Reduce on the sides operates parallel into the barrel. https://garrettzphpt.theblogfairy.com/18735050/the-ultimate-guide-to-firearms