hm1996, I could definitely buy the idea that the rifling had been damaged on those old M1's. I'm guessing they were issued and or cleaned with a steel cleaning rod.
For the record, I am a HUGE believer in good cleaning rods. It goes without saying those old steel ones could scratch and scar the throat and bore.
Worse than that are the screw together brass ones. Buddy of mine was too cheap to buy a decent cleaning rod; needles to say he ended up with one of those screw together ones in pieces and stuck in his bore, ouch.
