I have found using a greased felt wad, card over powder in a larger bore rifle with a slightly rougher bore than is ideal seems to shoot a lot better. I have a .72 English hunting rifle that. I am still cleaning the bore up. In fact I have to start again as the rifle was destroyed in a fire and I had it subsequently rebuilt. The barrel being of wrought iron was not affected by the fire. I have since re proofed it and been shooting it again . I have also done this wad over powder in a .62 original Baker sporting rifle with a similar improvement in accuracy .