be manufactured through injection molding a suitable polymer such as acrylonitrile butadiene styrene abs the rib stiffener 51 or most any other insert can be molded by injecting melted polymer resin such as abs into the mold and then allowing the mold to cool to form a solid part the stiffness of the injection molded part can be controlled by adding a small amount of carbon or glass fibers to the resin a prototype composite ribbed stiffener 51 such as that shown in fig1 and 13 has been manufactured and attached to the forward bourrelet 14 of a projectile using the methods described above the ribbed stiffener 51 was then tested by pushing inwardly on the forward bourrelet in the radial direction the ribbed stiffener 51 increased the radial stiffness of the forward bourrelet by 75 as compared to the unreinforced projectile the present invention can also be applied to the aft bourrelet 19 although all of the foregoing describes modifications to the forward bourrelet 14 it is not intended that the present invention be limited in application to only the forward bourrelet 14 if the aft bourrelet 19 is undercut the present invention may be applied to the aft bourrelet 19 in exactly the same manner as has been described for the forward bourrelet 14 furthermore although an important aspect of the present invention provides the ability to improve the performance of existing and or fielded rounds it must also be recognized that the principals of.