the tip is further chosen such that overall top eccentricity after truncation does not exceed three ounces in accordance with abc guidelines application_number US 6677593 A description as seen initially in fig1 the weight block of the present invention from which the core is formed has a head portion 10 a body portion 12 and a tip portion 14 typically formed out of a mass of one or more appropriate compounds typically polyesters or urethanes compounded and combined as known in the art to an appropriate overall density to allow the combination of the core and the shell 16 of the ball to fall within the 16 pound limit typically the weight block is of a greater total density than the shell although the density of the portions of the block may be variable controlled by the compounds utilized for the block and their relative positioning therein as used herein the term 34 density of the weight block 34 refers to the composite overall density of the block as a whole the density may be constant or variable through the different regions of the block the weight block is symmetric in shape about its centerline 24 prior to establishment of the line of demarcation for truncation as shown the head portion 10 is defined as a spherical segment whose top surface 18 is generally concentric with the outer surface of the ball as a regulation bowling ball is of 8 59 inch diameter the radius of curvature 42 for top surface 18 is in the order of 3 07 to 3 80 inches corresponding to a spacing distance between the ball surface and.