I have a 1975 M77V in 25.06 and a 1976 M77V in 22-250.
Both are great shooters. The 25.06 prefers the heavier bullets. Can't seem to get a decent load with the Sierra 90gr HP. Goodness knows I have tried.
The 117-120 gr. bullets work fine. The 250 likes the Sierra 52 gr. hpbt.