Reusable Plastic Ammunition Casing

Abstract

A reloadable plastic ammunition casing is provided for firearm use. The plastic casing is preferably constructed from currently available polymeric materials using plastic injection molding techniques. In the preferred embodiment the casing includes a cylindrical body having a top portion and a bottom portion. The top portion having an open end for receiving a propellant and a top lip for retaining a projectile. The bottom portion has an internal casing floor that includes at least one concentric step down towards a centrally located primer pocket such that an installed primer is located in blast communication with the concentric steps on the casing floor. The concentric steps uniformly disburse, distribute, and deflect the heat and gas pressures within the casing when fired, thereby avoiding structural failure, allowing for multiple reloads of a casing constructed entirely out of plastic.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority under 35 U.S.C. §119(e)(1) to U.S. Ser. No. 61 / 955,105 filed Mar. 18, 2014, which is hereby incorporated by reference in its entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT[0002]Not ApplicableBACKGROUND OF THE INVENTION[0003]1. Technical Field[0004]This invention relates generally to ammunition casings, specifically casings constructed entirely of plastic materials or injection moldable non-metallic materials.[0005]2. Background of Prior Art[0006]Although the word bullet is often used synonymously with a cartridge, for the purposes of this disclosure the term bullet only refers to the projectile. The cartridge includes several discrete parts, a bullet, a primer, propellant, and a casing. The bullet acts as a projectile that shoots out of the firearm. The primer is a detonation cap located within the base of the cartridge, containing a compound that directionally detonates to ignite...

AI Technical Summary

Benefits of technology

The invention is a plastic casing for ammunition that can be reused, made from a strong polymer material that withstands fire. The casing has internal steps that disperse force evenly, preventing any damage to the casing during firing. This allows for multiple reloads, similar to a brass casing.

Problems solved by technology

When the cartridge is fired, the primer is struck causing the primer to explode directionally forcing the blast into the propellant, which in turn combusts to make a larger explosion with the massive gas pressures necessary to project the bullet on its trajectory.

Brass mediums have been preferred in constructing cartridge casings due to the ready availability of brass, its strength, temperature stability, and durability that allows a brass cartridge to be reloaded several times. The downsides of brass include a relatively heavy weight, increasing cost of the raw material, and significant tooling is necessary to manufacture.

Further, brass is often deformed after just one shot, requiring resizing if reloaded.

Padgett does not teach an integrally formed casing constructed of a continuous flow of plastic medium able to be manufactured in a single shot injection process.

Instead Padgett's design is limited to multi-components that rely upon ‘plastic welds’ that are expected to hold for just one shot, and would be unloadable thereafter.

The lower portion is then partially filled with plastic, rather than allowing adequate space for propellant, thus limiting Trivette's casing application to limited propellant loads as used for blanks or target only.

The projectile end is proximal to the thinnest part of the casing wall at the location where the projectile seats and is one of the common failures of plastic casings.

Primer pocket failures are another common failure area of the plastic casting.

The gas pressures at the primer pocket are greatly magnified by the nozzle like effect of the Trivette's conical interior that literally focusses the opposing blast forces within the casing directly at the primer, causing leak by or burn through of the primer to primer pocket seal.

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