Light weight ammunition and firearm systems

Patent metadata

Field	Value
Publication number	US-12460907-B2
Application number	US-202218086046-A
Country	US
Kind code	B2
Filing date	Dec 21, 2022
Priority date	May 19, 2020
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

A firearm system includes a bolt carrier with an internal cavity, a piston disposed within the internal cavity, a forward configuration where the piston is in a forwardmost position relative to the bolt carrier, and an aft configuration where the piston is in a rearmost position relative to the bolt carrier. The piston slides forward and aft relative to the bolt carrier. In the forward configuration, the entire piston remains disposed within the bolt carrier.

First claim

That which is claimed is:

1 . A primerless firearm ammunition comprising:
a cartridge case comprising a rear face, a rim configured to interface with an extractor of a firearm, a rear cavity recessed from the rear face, and an internal cavity; a bullet disposed at least partially within the internal cavity, wherein: the rear cavity remains open to a rear side and empty; a rear membrane separates the rear cavity from the internal cavity; the rear membrane is thinner than all other portions of the cartridge case; and the rear membrane is a continuous barrier between the rear cavity and the internal cavity.

2 . The primerless firearm ammunition of claim 1 , wherein the cartridge case comprises a polymer material.

3 . The primerless firearm ammunition of claim 1 , wherein the rear cavity comprises at least one selected from the group of a paraboloid or a conical shape.

4 . The primerless firearm ammunition of claim 1 , wherein the internal cavity comprises at least one selected from the group of a paraboloid or a conical shape.

5 . The primerless firearm ammunition of claim 1 , further comprising a flammable material within the internal cavity.

6 . The primerless firearm ammunition of claim 1 , wherein the rear membrane is designed to be burned by a stream of fluid such that the stream of fluid would ignite a flammable material within the internal cavity.

7 . The primerless firearm ammunition of claim 1 , wherein the rear membrane is designed to be pierced by a stream of fluid such that the stream of fluid would ignite a flammable material within the internal cavity.

8 . The primerless firearm ammunition of claim 1 , wherein the cartridge case is overmolded onto the bullet.

9 . The primerless firearm ammunition of claim 1 , wherein the cartridge case comprises a portion where the total wall thickness is approximately 70% to 80% of the total diameter of the cartridge case.

10 . The primerless firearm ammunition of claim 1 , wherein the rear membrane is approximately 0.005 in thick.

11 . The primerless firearm ammunition of claim 1 , wherein the rear cavity comprises a circular opening at the rear face and tapers down to a smaller circular shape at the rear membrane.

12 . The primerless firearm ammunition of claim 1 , wherein the cartridge case comprises a mechanical feature for engaging the bullet.

13 . A primerless firearm ammunition comprising:
a cartridge case comprising a rear face, a rim configured to interface with an extractor of a firearm, a rear cavity recessed from the rear face, and an internal cavity; a bullet disposed at least partially within the internal cavity, wherein: a rear membrane separates the rear cavity from the internal cavity; the rear membrane is thinner than all other portions of the cartridge case; and the internal cavity comprises a mechanical feature for engaging the bullet.

14 . The primerless firearm ammunition of claim 13 , wherein the mechanical feature comprises an annular protrusion extending toward a center of the internal cavity and the mechanical feature is offset from a forward edge of the cartridge case.

15 . The primerless firearm ammunition of claim 14 , wherein the bullet comprises a corresponding groove designed to engage the annular protrusion.

16 . The primerless firearm ammunition of claim 13 , wherein the rear cavity remains open to a rear side and empty and the rear cavity comprises at least one selected from the group of a paraboloid or a conical shape.

17 . The primerless firearm ammunition of claim 13 , wherein the rear membrane is a continuous barrier between the rear cavity and the internal cavity and the rear membrane is designed to rupture to actuate/fire the firearm ammunition.

18 . The primerless firearm ammunition of claim 13 , wherein the cartridge case comprises a polymer material.

19 . The primerless firearm ammunition of claim 13 , wherein the rear membrane is approximately 0.005 in thick.

20 . The primerless firearm ammunition of claim 13 , wherein the rear cavity comprises a circular opening at the rear face and tapers down to a smaller circular shape at the rear membrane.

Assignees

• Underwood James Matthew
• Underwood Larry Cullen

Inventors

• Underwood James Matthew
• Underwood Larry Cullen

Classifications

• F41A5/18

  gas-operated · CPC title

• F41A3/26

  semi-automatically or automatically operated, e.g. having a slidable bolt-carrier and a rotatable bolt · CPC title

• F41A3/12

  Bolt action, i.e. the main breech opening movement being parallel to the barrel axis · CPC title

• F42B5/30

  of plastics {, i.e. the cartridge-case tube is of plastics} · CPC title

• F42B5/307 Primary

  formed by assembling several elements · CPC title