Patent attributes
A casing for use in a cartridge for a firearm comprises a sleeve and attached base. The sleeve has cylindrical portion with a mouth for holding a bullet and an opposing bulkhead from which extends a nipple. At the terminal end of the nipple is a lip that radially decreases in thickness and has curved surface portions; the lip forms a first seal region within a passageway that runs through the base. Preferably a second seal zone around the nipple near the bulkhead. A bulkhead comprises a circumferential wave or ridge that creates a hollow on the surface facing the base. A sleeve is preferably made of austenitic stainless steel that has differential hardness and magnetic properties along the sleeve length; and the base has a hardness less than any portion of the sleeve.
