I sighted in a new Ruger Gunsite Scout rifle (GSR) today, both with the irons and a Leupold 2.5 LER. All went as expected, using surplus 7.62x51 gave me approx. 3 MOA groups. Transitioned to factory Federal 150 & 180 .308 SP with predictable results and ~2 MOA.
Then decided to try some light...