Polymer ammunition cartridge having a metal injection molded primer insert

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.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of application Ser. No. 14 / 320,961, filed 1 Jul. 2014. The contents of which is incorporated by reference in its entirety.TECHNICAL FIELD OF THE INVENTION[0002]The present invention relates in general to the field of ammunition, specifically to compositions of matter and methods of making and using substantially cylindrical inserts made by metal injection molding.STATEMENT OF FEDERALLY FUNDED RESEARCH[0003]None.INCORPORATION-BY-REFERENCE OF MATERIALS FILED ON COMPACT DISC[0004]None.BACKGROUND OF THE INVENTION[0005]Without limiting the scope of the invention, its background is described in connection with lightweight polymer cartridge casing ammunition. Conventional ammunition cartridge casings for rifles and machine guns, as well as larger caliber weapons, are made from brass, which is heavy, expensive, and potentially hazardous. There exists a need for an affordable lighter weight replacement for brass ...

AI Technical Summary

Benefits of technology

The present invention provides an ammunition cartridge with a molded primer insert that has a flash hole and a flange. The molded primer insert is made of a metal, alloy, or ceramic alloy and is designed to be inserted into a polymer middle body and a polymer projectile end. The first polymer composition is the same as the second polymer composition and forms a flash hole. The flange is a combination of a circumferential groove and one or more notches. The technical effect of this invention is to provide a more reliable and efficient ammunition cartridge with improved performance and reliability.

Problems solved by technology

Conventional ammunition cartridge casings for rifles and machine guns, as well as larger caliber weapons, are made from brass, which is heavy, expensive, and potentially hazardous.

Plastic cartridge casings have been known for many years but have failed to provide satisfactory ammunition that could be produced in commercial quantities with sufficient safety, ballistic, handling characteristics, and survive physical and natural conditions to which it will be exposed during the ammunition's intended life cycle; however, these characteristics have not been achieved.

Shortcomings of the known methods of producing plastic or substantially plastic ammunition include the possibility of the projectile being pushed into the cartridge casing, the bullet pull being too light such that the bullet can fall out, the bullet pull being too insufficient to create sufficient chamber pressure, the bullet pull not being uniform from round to round, and portions of the cartridge casing breaking off upon firing causing the weapon to jam or damage or danger when subsequent rounds are fired or when the casing portions themselves become projectiles.

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