GB841901A - Ammunition cartridges - Google Patents

Abstract

841,901. Ammunition cartridges. OLIN MATHIESON CHEMICAL CORPORATION. Sept. 16, 1957, No. 29135/57. Class 9(1). A shot-gun cartridge having a case of pliable resinous material such as polyethylene with a liner of non- resinous material separating the shot from the case is formed by moulding, a brass washer 10 being placed in the die around the pin used to form the primer cavity 3 before introducing the plastic material. The case wall 1 is tapered in thickness from the base 2 to the mouth 4. After the moulded case has cooled a primer assembly is inserted in the cavity 3, a wad 15 followed by a propellant charge 6 and further wads 7, 8 are then introduced into the case. A paper liner 9 is placed on the wad 8 and filled with shot 20 before inserting a closure wad 12 and bending or crimping the case over the wad 12 at about 75‹C. A paper disc is forced through a die by means of a punch to form the liner 9 having pleats 16, in the sidewall, Fig. 4. Alternatively the liner 9 may be made from three discs of stepped diameter arranged concentrically before being forced through the die. The discs may be glued together. A liner, which may be partially embedded in the case, open at both ends may be used. The moulding resin may be 80 parts polyethylene mixed with 20 parts calcium carbonate moulded at 450‹F.,the injection pressure being 10,000 lbs. p.s.i. Fibre glass may be added to the resin composition. The primer 11 instead of having force fit in the cavity 3 may be secured by adhesive. The liner 9 may be slit at intervals to remove excess paper and the resulting edges overlapped to form the tube.