For what? And it totally depends on the gun. I have a 444 marlin that shoots jacketted way better than cast and a 336 that shoots cast much better than jacketted. I have loaded jacketted bullets that don't do so hot in thick brush and jacketted bullets that could easily kill a bear on the other side of a small tree.
For a 30-30, even a gas checked hard cast is at a disadvantage at longer distance. A 32 special probably can't develop enough pressure to really take advantage of a jacketted bullet. The 444 and 45-70 are both oddballs in that the only bullets light enough to develop the speed necessary to demand jacketted bullets are so light that they lack the BC to make up the difference at longer ranges. So I think you'd pick the bullet weight and composition that the gun shoots best.
In a ruger no. 1 or mauser conversion chambered in 45-70, I suspect you could load up some 400+gr JFPs that would have a long distance advantage over any cast boolit on moose, elk, buffalo, brownies, and other very large game. It sounds like you're talking lever guns though.
