Some on line info on Hathcock's stuff:
I believe his scope was a Unertl 1-1/4 inch target/varmint version that the military bought by the dozens. This is what Erik England ('nother sniper) told me at a match in the early 1970's.
In the late '60's, the US Navy Small Arms Match Conditioning Unit put Redfield 3-9x scopes on the Remington 700's they built. Watched 'em testing those rifles with a 20-inch silencer on the muzzle at 600 yards. A good lot of M118 match ammo shot about 6 inches; not bad at all with a silencer.
Too bad those scopes had half a minute or more slop in their zoom optics as well as their adjustments; they were put hard into 9X on zoom to keep the zoom lens groups from shifting from recoil when used by SEAL teams. I borrowed three of them from the Unit to test on my collimator. Sure enough; they had that much slop in W & E adjustments, almost 1 moa in their zoom optics. Redfield never fixed this in their last target scope Lones Wigger brought me one to test about 10 years ago; it was just as sloppy as all their previous ones. I uses to shoot matches with a Redfield employee; he said, with much dismay, the company was more interested in profit than quality and most of their customers would never notice it anyway.