It isn't the same gun, but my old bushy hated light bullets. Mine preferred near max loads of H335 and A2230, 55gr Sierra Blitzkings, and Federal primers. That is about all I can give to you that might help.
I will say it was a sub-MOA rifle with any bullet 55gr and up and that was with the trigger it came with. I won quite a few matches and bets with he scope off it.
Here is my brother and I on it years ago blasting pigeons out to 500yds. (most of our hits were under 400 though):