AMMUNITION CASING

摘要

An ammunition article is provided which comprises a casing and a cap wherein the casing is formed from a polymeric material that has a room temperature notched Izod impact value greater than about 10 ft lbs/in and then has a ratio of notched Izod impact value at room temperature to notch Izod impact value at about -40 °C of less than about 4. Alternatively the casing may be formed from - a polyphenylsulf one or - a Siloxane-modif ied Bisphenol-A polycarbonate or - a Bisphenol-A polycarbonate with biphenyl linkages or - a blend comprising Bisphenol-A polycarbonate and an acrylic elastomer. There is also provided a method of improving the viscoelastic response of a polymeric ammunition cartridge casing material by blending the material with a high modulus polymer.