Firearm casing with shroud

A casing, for use as part of a cartridge for a firearm, comprising

• a sleeve and a base connected to each other, the base comprised of a base substrate and a shroud;
• each of the sleeve, base, base substrate, and shroud having a length, a lengthwise axis, a distal end, a proximal end, and an exterior surface;
• the base and the sleeve having abutting exterior surfaces that comprise a casing exterior surface;
• the base substrate having a lengthwise passageway, wherein a portion of the passageway is a recess at the distal end of the base substrate shaped for receiving a primer, the recess defining a shoulder within the passageway;
• the sleeve having a length, a proximal end comprising a mouth opening shaped for receiving a bullet, a circular wall portion running in the direction of the sleeve distal end, a bulkhead integrally connected to said wall portion at a bulkhead circular outer edge and running substantially transverse to the sleeve length, and a nipple extending lengthwise from the bulkhead in the direction of the base distal end;
• wherein the nipple is positioned within said passageway of the base substrate and secured therein by an outwardly flaring lip of the nipple which is in contact with the shoulder of the base substrate;
• and,
• wherein the shroud is mounted on a portion of the exterior surface of the base substrate and comprises a substantially cylindrical ring portion;
• wherein a portion of the base substrate exterior surface and a portion of the shroud exterior surface in combination form the exterior surface of the base;
• wherein the proximal ends of both the shroud and the base substrate form a base proximal end surface which is in contact with or in close proximity to said sleeve bulkhead;
• and,
• wherein the shroud proximal end has an exterior diameter matching the diameter of the circular outer edge of the sleeve bulkhead.