Method of making a primer insert for use in polymer ammunition

Patent metadata

Field	Value
Publication number	US-9933241-B2
Application number	US-201715406844-A
Country	US
Kind code	B2
Filing date	Jan 16, 2017
Priority date	Nov 10, 2010
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

One embodiment of the present invention provides a polymeric ammunition cartridge and methods of making and using the same. The cartridge includes a substantially cylindrical insert connected to a substantially cylindrical polymeric middle body. The substantially cylindrical insert includes a top surface opposite a bottom surface and a substantially cylindrical coupling element that extends from the bottom surface, a primer recess in the top surface that extends toward the bottom surface, a primer flash hole 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. The substantially cylindrical polymeric middle body includes a substantially cylindrical polymeric bullet-end and a substantially cylindrical polymeric coupling end connected by a powder chamber, wherein the substantially cylindrical polymeric coupling end extends over the substantially cylindrical coupling element and covers a circumferential surface of the primer flash hole.

First claim

What is claimed is:

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

2. The method of claim 1 , wherein the metal primer insert is a 5.56 mm, 7.62 mm, .223, 308, 338, 3030, 3006, and .50 caliber primer insert.

3. The method of claim 1 , wherein the metal primer insert is a 380 caliber, 38 caliber, 9 mm, 10 mm, 20 mm, 25 mm, 30 mm, 40 mm, 45 caliber and the like.

4. The method of claim 1 , wherein the insert blank is a metal, an alloy, or a ceramic alloy.

5. The method of claim 1 , wherein the insert blank is stainless steel or brass.

6. The method of claim 1 , wherein the insert blank is a 102, 174, 201, 202, 300, 302, 303, 304, 308, 309, 316, 316L, 316Ti, 321, 405, 408, 409, 410, 415, 416, 416R, 420, 430, 439, 440, 446 or 601-665 grade stainless steel.

7. The method of claim 1 , wherein the insert blank is a Ti 6 Al 4 V.

Assignees

• True Velocity Inc

Inventors

• Burrow Lonnie

Classifications

• F42B33/02

  Filling cartridges, missiles, or fuzes; Inserting propellant or explosive charges {(F42B33/004 takes precedence)} · CPC title

• B22F3/004

  Filling molds with powder (feeding material to presses in general B30B15/302) · CPC title

• B22F5/06

  of threaded articles, e.g. nuts · CPC title

• F42B5/313

  all elements made of plastics · CPC title

• F42B5/025

  characterised by the dimension of the case or the missile · CPC title