Engineered neck angle ammunition casing

An ammunition article comprising;

• a casing defining a generally cylindrical hollow body having internal and external walls, the casing having a cap at a first end thereof and a pressure vessel at a second end thereof, the pressure vessel having a proximal end defining a body region and a distal end defining a neck region, wherein the cap is interconnected with the proximal end of said pressure vessel such that the casing at least partially encloses an internal volume, and wherein the diameter of the pressure vessel narrows from a first diameter at the body region to a second diameter at the neck region;
• wherein at least the neck region of the pressure vessel at least partially comprises a substantially polymeric material;
• and
• wherein the geometry of the internal and external walls of the casing in the neck region of the casing are independent of each other.