The present invention provides polymer ammunition 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 polymer ammunition 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 method of manufacturing an iron soap is disclosed herein. The method comprising the steps of: reacting, at a temperature equal to or lower than a crystal transition initiation temperature of the iron soap to be manufactured, between a straight-chain saturated fatty acid alkali metal salt aqueous solution having from 12 to 22 carbons and a trivalent iron salt aqueous solution with pH of 0.1 to 5.5 so as to prepare an iron soap slurry; and adjusting pH of the prepared iron soap slurry to from 0.1 to 6.0.

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 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 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 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 powder mixture for powder metallurgy includes a raw material powder, a binder, and a graphite powder, where the raw material powder contains an iron-based powder in a content of 90 mass % or more of the raw material powder, the graphite powder has an average particle size of less than 5 μm, a ratio in mass of the binder to the sum the raw material powder and the graphite powder is 0.10 mass % to 0.80 mass %, a ratio of mass of the graphite powder to the sum of mass of the raw material powder and mass of the graphite powder is 0.6 mass % to 1.0 mass %, surface of the raw material powder is covered with at least a part of the binder, and surface of the binder covering the surface of the raw material powder is covered with at least a part of the graphite powder.

The powder mixture for powder metallurgy includes a raw material powder, a binder, and a graphite powder, where the raw material powder contains an iron-based powder in a content of 90 mass % or more of the raw material powder, the graphite powder has an average particle size of less than 5 μm, a ratio in mass of the binder to the sum the raw material powder and the graphite powder is 0.10 mass % to 0.80 mass %, a ratio of mass of the graphite powder to the sum of mass of the raw material powder and mass of the graphite powder is 0.6 mass % to 1.0 mass %, surface of the raw material powder is covered with at least a part of the binder, and surface of the binder covering the surface of the raw material powder is covered with at least a part of the graphite powder.

Fine metal particles of any one of Ag, Cu or Zn having a dispersing agent that is coordinated on the surfaces thereof, the dispersing agent having an acid value and an amine value which are both in a range of 0 to 20 mgKOH/g (wherein when either the acid value or the amine value is 0, the other one is not 0), and a dispersion solution in which the fine metal particles are dispersed. The fine metal particles and the dispersion solution containing the fine metal particles can be diluted with various kinds of solvents of either the water type or the organic type, and feature excellent dispersion property even after having been diluted.