I have two Handi rifles. One in .308 Winchester and one in .444 Marlin. They both shoot jacketed bullets well. (Of course) Cast bullets? Not so much. I've tried a number of different bullet styles and loads. No help. All over the map. Mind you I'm not getting and leading. Just "pie plate" groups. I took time to examine the chamber & throat. I noticed that the rifling in both rifles had no taper/leade when approaching the throat. It just looks like the rifling is "chopped off" square. Me thinks that could be the problem. I've never done any throat work. So . . . I'm looking for advice as to what to do.
If someone else had of done to me what I did to myself . . . I'd have killed him. Humility is an asset. Heh - heh.