In the late 1980's my best friend was on the Ohio National Guard rifle team. He was issued an Match M-14 (still select fire) and with M118 ammo (Camp Perry Match 173 grain) and match iron sights could shoot 1.5 to 2 MOA out to 600 yards. At the same time I had a semi-auto HK 91 . Using Israeli 1973 ball ammo and the factory equipped sights with the apertures readjusted to 100, 200, & 300 Meters (instead of point blank notch, 200, 300, & 400 meters) I would get 1 MOA and with a 10 power scope 1/2 MOA was very easy. Never tried 168 or 173 grain ammo.
My current AR in 308 seems to be a 2.5 to 3 MOA ( or worse depending on ammo) rifle with a scope and will probably be getting traded for something more accurate. It seems America isn't producing accurate guns in favor of affordable ones currently (I wouldn't call $1450 for a gun that won't group Cheap!)
Ivan