It is well recognized in the art of propellant charge casings that reducing the deadload component is desireable, particularly in cartridged ammunition. One arrangement for doing so is disclosed in U.S. Pat. No. 2,991,168, wherein the ammunition propellant charge casing is at least partially made out of a combustible material. In contradistinction to conventional propellant charge casings, which are made completely of metal, this state-of-the-art casing has a metallic component which is at most the cartridge casing bottom, a reusable part of the casing. However, the manufacture of a combustible casing part involves many steps and is quite complex and expensive. Moreover, the partially combustible casing material has an unsatisfactory mechanical strength.
USPTO Backgrounds
USPTO Backgrounds