My experience with a B-78 .30-06 mirrors yours. Several cast bullets ranging from 150-220 grains performed beautifully. Killed a few deer with a custom Saeco 180 grain FN bullet cast soft and driven with SR-4759 powder for .32-40-level performance (but most of my kills with it were with 165 Sierra HPBT's). It delivered MOA and sub-MOA accuracy with most every thing I fed it. It was at the top of the rotation in my go-to deer rifles for a couple decades, and then I sold it along with a few others when scrounging together the funds for a healthy down payment on a house.
It was the first rifle on which I tackled the factory wood finish early on. Stripped it (what a chore!), refinished it, and removed recoil pad and replaced it with a Model 70 butt plate. Left the high comb cheek piece as it worked quite well for scope use. If one of y'all happens to own that rifle now.....
