Kraig, I had one of those Win 70 .308 match rifles like yours. Someone on a ship I was stationed on in 1975 had ordered it through Special Services, but ended up not being able to pay for it. So it sat in the ship's small arms magazine for a year or so. The Ships Store OIC said I could have it for $50; I bought it.
It shot the old WCC 197-gr. BTHP match bullets (from WCC60 match ammo) under 1 MOA at 1000 yards. It's barrel had a .3084" groove diameter and the .3082" diameter Sierra HPMK's didn't shoot too well. But those .3088" diameter WCC 197's did great. Even won a Palma match shooting them in it.
Sold that rifle to someone a few years later for a big wad of greenbacks.
US Navy Distinguished Marksman Badge 153
Former US Navy & Palma Rifle Team Member
NRA High Power Master & Long Range High Master
NRA Smallbore Prone Master