Abstract: A method of manufacturing a casing for an ammunition cartridge includes injection molding a first polymer forming a first part of the casing. The first part is cylindrically shaped along a longitudinal axis extending from a projectile end opposite a stepped end. The stepped end forms a first end of a mechanical connection. A portion of the injection mold is removed and an additional injection mold is disposed about the stepped end of the first end of the first part and a second polymer injected forms a second part of the casing. The second part includes a second stepped end forming a second end of the mechanical connection. The first and second end are mechanically locked together preventing a separation of the first part from the second part. A thermal swagging tool forms a conical tapered region along the projectile end of the first part.

Abstract: A method of manufacturing a casing for an ammunition cartridge includes injection molding a polymer forming the casing using an injection mold. The casing is cylindrically shaped along a longitudinal axis extending from a base to a distal end with a blind hole formed therein. The blind hole has a primer retention feature disposed at the base and leads into a flash hole. An insulator and/or reflector is placed around at least a portion of the casing separating the base from the neck. A heater directly heats the neck of the casing while not directly heating the base. A stretch rod is inserted into the blind hole stretching the neck. The casing is inserted into a blow mold and pressurized causing the neck of the casing to be blow molded. At least a portion of the distal end of the casing is removed.