the first peripheral region 44 has a thickness range of 0 105 inch to 0 090 inch and the second peripheral region 46 has a thickness range of 0 075 inch to 0 050 inch preferably as shown in fig2 the central region 40 is 5 to 15 of the surface area of thee core face 49 of the striking plate 30 the core face 49 is defined as the central region 40 the transition region 42 and the first peripheral region 44 the core face area of the striking plate 30 has an area between 4 80 square inches and 5 50 square inches preferably between 5 10 square inches and 5 40 square inches and most preferably 5 38 square inches the transition region 42 is preferably 35 to 50 of the surface area of the core face 49 and the first peripheral region 44 is preferably 40 to 55 of the surface area of the core face 49 in a preferred embodiment the central region is 8 8 of the surface area of the core face 49 the transition region is 42 2 of the surface area of the core face 49 and the first peripheral region 44 is 50 of the surface area of the core face 49 fig7 illustrates an alternative embodiment of.