A method of making a ball, comprising: forming an inner core having a diameter of about 0.5 inches or lower; forming a plurality of outer core parts from an elastomeric material, each outer core part having an inner surface, an outer surface and at least one non planar mating surface, wherein the inner surface is concentrically disposed within the outer surface and comprises a cavity for receiving the inner core, and wherein the at least one nonplanar mating surface extends radially between the inner surface and the outer surface and comprises a plurality of mating ridges which extend from the inner surface to the outer surface; forming an outer core by mating the outer core parts about the inner core and joining the nonplanar mating surfaces by meshing the mating ridges to form a multi-layer core having a nonplanar parting line which extends about the outer surface circumferentially and intersects with the mating ridges at the outer surface; and molding a cover about the inner core, wherein the elastomeric material has a cohesive strength and the parting line has a mated strength equal to or greater than the cohesive strength.