One embodiment of the present invention provides a method of stamping a metal primer insert for a polymeric ammunition cartridge comprising the steps of: providing an insert blank for stamping; stamping the insert blank to form a top surface having a flange that extends circumferentially about an outer edge of the top surface; stamping the insert blank to form a substantially cylindrical coupling element that extends from the flange to a coupling tip; stamping the insert blank to form an inner coupling element from the coupling tip to a bottom surface, wherein the bottom surface is opposite the top surface; stamping the insert blank to form a primer recess in the top surface that extends toward the bottom surface; stamping the insert blank to form a primer flash aperture in the primer recess through the bottom surface; and stamping the insert blank to form a groove in the primer recess around the primer flash aperture adapted to receive a polymer overmolding.

A fragment-free propulsion of a cartridge-type ammunition, including a propellant casing and a high-pressure chamber, wherein the high-pressure chamber accommodates a propellant powder and, in the bottom region, a primer, having at least one overflow bore. To avoid fragments, a membrane, which separates the high-pressure chamber and a low-pressure chamber from one another and which does not tear to connect the high-pressure chamber to the low-pressure chamber when pressure is built up but instead is bent, is embedded in the high-pressure chamber. For this purpose, the high-pressure chamber additionally has a cap, the membrane, and a body. The membrane is embedded in the body and is secured by the cap. In addition, the membrane covers a gap that is formed by an outer diameter of the cap and an inner diameter of the body, and into which the membrane is bent when pressure is built up.

A propellant is made from a flexible sheet that in some examples is nitrocellulose. An ignitable material is deposited on one side of the flexible sheet. The ignitable material is a series of triangles having a base adjacent to one edge of the sheet, and an apex adjacent to the other side of the sheet. Some examples of the ignitable material may be thermite compositions. The flexible sheet is rolled around a nonburnable tube and placed within a firearm casing, with the triangle bases being adjacent to the back of the casing, and the triangle apexes being adjacent to the front of the casing. The nonburnable tube is disposed over the primer pocket, so that ignition products from the primer travel through the tube, igniting the propellant adjacent to the front of the casing.

The present invention provides a single piece polymer ammunition cartridge and polymer ammunition and methods of forming a single piece polymer ammunition cartridge and polymer ammunition.

The present invention provides a single piece polymer ammunition cartridge and polymer ammunition and methods of forming a single piece polymer ammunition cartridge and polymer ammunition.

The present invention provides a single piece polymer ammunition cartridge and polymer ammunition and methods of forming a single piece polymer ammunition cartridge and polymer ammunition.

The present invention provides a polymer ammunition cartridge having a primer insert having: a top surface; a bottom surface opposite the top surface; a coupling element that extends from the bottom surface, wherein the coupling element comprises an interior surface and an exterior surface, wherein the interior surface comprises: a transition region that transitions from the bottom surface to a second segment wherein the transition region has a radius of from 0.02 to 0.08; a first segment extending from the second segment and terminates at a tip, wherein the first segment has a first segment distance from 0.05 to 0.09 inches and the second segment has a second segment distance from 0.05 to 0.09 inches, wherein the second segment has a second segment angle from +3 to 3 degrees relative to the first segment angle and the first segment has a first segment angle from +6 to 6 degrees from perpendicular to the top surface; a primer recess in the top surface that extends toward the bottom surface; a primer flash aperture positioned in the primer recess through the bottom surface; and a flash aperture groove in the primer recess and positioned around the primer flash aperture and adapted to receive a polymer overmolding through the primer flash aperture.

The present invention provides a polymer ammunition cartridge having a primer insert having: a top surface; a bottom surface opposite the top surface; a coupling element that extends from the bottom surface, wherein the coupling element comprises an interior surface and an exterior surface, wherein the interior surface comprises: a transition region that transitions from the bottom surface to a second segment wherein the transition region has a radius of from 0.1 to 0.2; a first segment extending from the second segment and terminates at a tip, wherein the first segment has a first segment distance from 0.06 to 0.14 inches and the second segment has a second segment distance from 0.05 to 0.15 inches, wherein the second segment has a second segment angle from +3 to 3 degrees relative to the first segment angle and the first segment has a first segment angle from +6 to 6 degrees from perpendicular to the top surface; a primer recess in the top surface that extends toward the bottom surface; a primer flash aperture positioned in the primer recess through the bottom surface; and a flash aperture groove in the primer recess and positioned around the primer flash aperture and adapted to receive a polymer overmolding through the primer flash aperture.

The present invention provides a polymer ammunition cartridge having a primer insert having: a top surface; a bottom surface opposite the top surface; a coupling element that extends from the bottom surface, wherein the coupling element comprises an interior surface and an exterior surface, wherein the interior surface comprises: a transition region that transitions from the bottom surface to a second segment wherein the transition region has a radius of from 0.02 to 0.2; a first segment extending from the second segment and terminates at a tip, wherein the first segment has a first segment distance from 0.02 to 0.18 inches and the second segment has a second segment distance from 0.02 to 0.18 inches, wherein the second segment has a second segment angle from +3 to 3 degrees relative to the first segment angle and the first segment has a first segment angle from +6 to 6 degrees from perpendicular to the top surface; a primer recess in the top surface that extends toward the bottom surface; a primer flash aperture positioned in the primer recess through the bottom surface; and a flash aperture groove in the primer recess and positioned around the primer flash aperture and adapted to receive a polymer overmolding through the primer flash aperture.

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 radially-running bulkhead from which extends a nipple that is secured within a passageway of the base by a lip at the nipple terminal end. There are one or more seal regions in the passageway. A sleeve is preferably made of austenitic stainless steel and there are differing hardness and magnetic properties along the sleeve length. Particularly for high pressure rounds, the bulkhead has a frusto-conical portion with one or more circumferential waves and mates with a conical depression in the surface of the base; optionally, a skirt around the periphery of the base provides support to the sleeve bulkhead. A base has a deep cannelure with a continuously curving groove bottom, enabling a base to be made of an iron alloy into which carbon is diffused to enable hardening, after machining.