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.

The present invention provides an injection molded primer insert for polymer ammunition comprising: a top surface opposite a bottom surface; a primer flash hole aperture positioned in the top surface extending through to the bottom surface; a substantially cylindrical coupling element extending away from the bottom surface forming an interior surface inside the substantially cylindrical coupling element and an exterior surface; a primer recess in the top surface that extends toward the bottom surface, a primer flash aperture positioned in the primer recess to extend through the bottom surface, and a flange that extends circumferentially about an outer edge of the top surface, wherein the flange is adapted to receive a polymer overmolding.

The present invention provides a diffuser cup adapted to fit a primer recess in an ammunition cartridge comprising: a diffuser ring sized to fit in a primer recess for an ammunition cartridge comprising a diffuser top surface opposite a diffuser bottom surface, a diffuser aperture positioned through the diffuser top surface and the diffuser bottom surface such that the diffuser aperture can align with a flash hole, a diffuser neck positioned about the diffuser aperture to extend away from the diffuser top surface, wherein the diffuser neck is sized to fit at least partially through the flash hole; a ring connected to the diffuser neck, wherein the ring comprises a ring aperture connected to the diffuser neck to align the ring aperture and the diffuser aperture; and a cup wall attached to the diffuser ring to extend away from the diffuser bottom surface, wherein the cup wall is configured to frictionally fit a primer and frictionally fit a primer recess.

A .22 caliber rimfire cartridge includes a generally cylindrical casing having a rearward rimfire end and an opposing mouth end, wherein the rearward rimfire end has an annular rim connecting to a cylindrical casing portion extending to a casing forward edge and a bullet is disposed in the forward mouth end. In embodiments, the bullet comprises copper and a polymer binder. In embodiments, the bullet has a forward tapering portion with a central cavity, a first cylindrical portion with a first diameter and a cylindrical surface directly rearward of the tapering portion, a cylindrical driving band directly rearward of the first cylindrical portion, the cylindrical driving band having a second diameter greater than the first diameter and having an outer second cylindrical surface, a third cylindrical portion directly rearward of the cylindrical driving band, the third cylindrical portion having a third cylindrical surface with a diameter equal to the first diameter. In embodiments, the bullet is positioned with the third cylindrical surface mostly or entirely within the casing. In embodiments, the casing has a circumferential crimp positioned at the third circumferential portion. In embodiments, the third circumferential surface having a circumferential indentation at the circumferential crimp.

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

Devices and methods for chambering and releasing a high pressure cartridge case from a firearm. In some embodiments, a static chamber insert of high elastic modulus is disclosed. In some embodiments, a dynamic or adaptable chamber insert that radially expands in an out-of-battery configuration and radially contracts in a battery configuration is disclosed.

Devices and methods for an 8 mm semiautomatic handgun cartridge providing a reduced form factor for carrying a greater number of rounds in a smaller space while maintaining ballistic performance.

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.

Disclosed is an extended range multi-caliber in-bore laser boresight system for sighting in a firearm. The device includes one or more hollow cartridge cases that resemble a standard firearm case lacking a bullet, a laser module, and an external electronic package. The laser module fits within the hollow cartridge case and is positioned within a firearm chamber. The laser exits the hollow cartridge through the firearm barrel to aid with zeroing a firearm sighting system. The laser diode is powerful enough to be visible at extended ranges in bright sunlight. The inventive boresight system can be used for zeroing any desired caliber, such as from 5.56 NATO to .50 BMG at extended range.

Devices and methods for reducing tension force on a projectile by a neck of a cartridge case. A two-stage neck has a clearance band and an interference band, the clearance band providing a reduced retention force on the projectile relative to the interference band.