US Patent 9091516 Ammunition cartridge case bodies made with polymeric nanocomposite material

The present invention is directed to a three-part ammunition cartridge casing body comprising a head or base portion, a case portion and a cap portion. The cartridge casing body further comprises: the base portion, made of metal or polymeric resin, having a closed end and an open end; a substantially cylindrical case portion, open on both ends, joined to the open end of the base portion and comprising a nanocomposite material of a nanoclay dispersed in a polyamide resin matrix; and a cap portion, made of a nanocomposite material of a nanoclay dispersed in a polyamide resin matrix and further comprising glass fibers, joined to the other end of the case portion, wherein the case portion is more ductile than the cap portion.