A ball bat includes at least one disc member in the bat barrel. The at least one disc member may include at least one solid disc member or at least one non-solid disc member with an opening, or both. The outer perimeters of the disc members may optionally be separated from the inner wall of the ball bat by a buffer layer, such as a layer of open-cell foam or adhesive. In some embodiments, the ball bat may further include at least one positioning member, such as an insulation foam member. The at least one positioning member may be located between two disc members, and multiple positioning members may optionally be arranged in alternating fashion with disc members within the bat. The at least one positioning member may be an insulation foam member having a hollow center portion.