A stackable wire core assembly for a bedding foundation which may be nestably stacked with numerous other such assemblies for transportation, thereby avoiding the need to compress and tie the assembly for shipping. The wire core assembly includes an upper wire grid, including a border wire and support wires extending between the ends of the border wire. Each support wire has resilient portions extending downwardly from the plane of the upper wire grid, each resilient portion having a flat bottom adapted to be secured to a wooden base frame and curved arms extending upwardly from opposed ends of the flat bottom.