Hathcock used a Win Mod 70 Target rifle in 30.06 during his first tour in Nam.
Then used a Rem 700 in 7.62 NATO (.308) when that was issued.
His opinion of combat sniping was that his target was the 36" from the belt up to the chin down. Interesting how we get so caught up in 1" or 1/2" groups etc when one of the greats considered his target to be 36 inches.
He did shoot a 300 mag but that was in competion not combat.