some serious idiocy in that post. The 300 WM was not introduced until 1963. It was not a NATO standard caliber at any time in the Nam period while the 30-06 (M2 ball) was rather common since most of our WWII era weapons used that from the Browning 30 caliber machine guns, the MI garand and the A3 O3 springfield rifle. Hathcock won the national match with a 30-06 and at the time the army competition shooters were using 30-06 rifles mainly in competition be it scope for the wimbledon cup and iron sights for the service rifle matches with garands and sprinfields and some (later though) USAMU armory rebuilt M14s
BTW WHEN DID Hathcock win the NR championships? 1965, only two years after that new cartridge had been introduced. I know he won it with a 30-06 because one of his students noted it was the same rifle he used in Nam.
To kill the enemy, Hathcock generally used the standard sniper rifle: the Winchester Model 70 .30-06 caliber rifle with the standard 8-power Unertl scope. On some occasions, however, he used a different weapon: the .50-caliber M2 Browning Machine Gun, on which he mounted the Unertl scope, using a bracket of his own design.
Carlos Hathcock | History Wars Weapons