Abstract: An ammunition cartridge has a plastic case and a metal base having a plurality of grooves around the periphery thereof. The plastic case has an interference fit with the base. The plastic creeps into the grooves after being interference fit over the base to relieve the stress in the plastic. A stress modulator ring surrounds the plastic member in the area of the grooves.

Abstract: Controlling the release from a conical ceramic crucible of molten thermite eaction products (generally, iron and alumina) to effect optimum penetration of metallic targets by said molten products through the use of metallic discs which are completely protected on their sides against the molten products, thus forcing these molten products to melt the discs sequentially from top to bottom, resulting in a delay of flow of the molten products from the conical crucible to thus permit the molten iron, heavier than the molten alumina, to substantially unimpededly transfer its heat to the metallic target, the molten iron being more efficient in melting metallic materials than the molten alumina.

Abstract: 1. A device including an expendable cartridge-barrel assembly comprising a cartridge casing forming a barrel, the wall thickness of said barrel being at least equal to about the diameter of the bore therein, a retainer affixed to and rearwardly of said casing, a high energy propellant enclosed within said assembly, a primer within said retainer and communicating with said propellant, a projectile frictionally fitted within and extending along the bore of said barrel and having a rear end in proximate relation to said propellant, said projectile being designed for high sectional density and minimum drag with water, and a watertight seal affixed to a front end of said cartridge-barrel assembly.