Polymeric cartridge assembly

1. A polymeric cartridge subassembly for use in medium caliber weaponry, comprising:

a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween, the rearward surface including a primer recess for receiving a primer, the primer recess having an opening extending into an interior portion of the subassembly forming a combustion chamber;

a polymeric casing having a forward end opening, an opposite end, and a middle body portion therebetween, the forward end opening adapted to receive a projectile, the opposite end forming a coupling end sized to and being mated with the base coupling element, the polymeric casing formed from a graphene-reinforced polymer matrix composite; and

a retaining insert received within a combustion chamber of the polymeric casing, the retaining insert ensuring engagement between the polymeric casing and the metallic base;

wherein the base includes a plurality of apertures disposed around an arch length of the base and in communication with the combustion chamber of the polymeric casing, and a mechanical fastening member received in each of the plurality of apertures forming a compression assembly between the polymeric casing, the metallic base, and the retaining insert.

2. The polymeric cartridge subassembly of claim 1 , wherein the polymeric casing includes a shoulder portion for couplable engagement with the metallic base forward surface such that a ledge member of the metallic base receives the casing opposite end during subassembly.

3. A polymeric cartridge subassembly for use in medium caliber weaponry, comprising:

a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween, the rearward surface including a primer recess for receiving a primer, the primer recess having an opening extending into an interior portion of the subassembly forming a combustion chamber;

a polymeric casing having a forward end opening, an opposite end, and a middle body portion therebetween, the forward end opening adapted to receive a projectile, the opposite end forming a coupling end sized to and being mated with the base coupling element, the polymeric casing formed from a graphene-reinforced polymer matrix composite;

wherein the graphene-reinforced polymer matrix composite comprises 35% graphite in 65% polyether-ether-ketone (PEEK) polymer that has been fully exfoliated.

4. A polymeric cartridge subassembly for use in medium caliber weaponry, comprising:

a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween, the rearward surface including a primer recess for receiving a primer, the primer recess having an opening extending into an interior portion of the subassembly forming a combustion chamber;

a polymeric casing having a forward end opening, an opposite end, and a middle body portion therebetween, the forward end opening adapted to receive a projectile, the opposite end forming a coupling end sized to and being mated with the base coupling element, the polymeric casing formed from a graphene-reinforced polymer matrix composite;

wherein the graphene-reinforced polymer matrix composite comprises 20% graphite in 80% polyphenylene sulfide (PPS) that has been fully exfoliated.

5. The polymeric cartridge subassembly of claim 1 , wherein the graphene-reinforced polymer matrix composite is formed from a thermoplastic selected from the group consisting of: high density polyethylene, polyethylene terephthalate, polystyrene, polyamide 6-6, polysulfone, polyphenylene sulfide, and polyether-ether-ketone.

6. The polymeric cartridge subassembly of claim 3 including a retaining insert received within a combustion chamber of the polymeric casing, the retaining insert ensuring engagement between the polymeric casing and the metallic base.

7. The polymeric cartridge subassembly of claim 6 , wherein the base includes a plurality of apertures disposed around an arch length of the base and in communication with the combustion chamber of the polymeric casing, and a mechanical fastening member received in each of the plurality of apertures forming a compression assembly between the polymeric casing, the metallic base, and the retaining insert.

8. The polymeric cartridge subassembly of claim 1 wherein the forward end opening includes at least one protrusion on an interior surface and extending radially inwards towards the polymeric casing.

9. The polymeric cartridge subassembly of claim 8 , wherein the at least one protrusion comprises an Acme thread pattern and a tear perf at a root of the Acme thread pattern.

10. The polymeric cartridge subassembly of claim 1 , wherein the subassembly comprises a medium caliber ammunition subassembly for use with medium handheld, crew-served, ground, platform, and aircraft mounted weapons.

11. A polymeric cartridge subassembly for use in medium caliber weaponry, comprising:

a metallic base having a rearward surface, an open forward surface, and a coupling element therebetween, the rearward surface including a primer recess for receiving a primer, the primer recess having an opening extending into an interior portion of the base;

a polymeric casing having a forward end opening, an opposite end, and a middle body portion therebetween, the forward end opening adapted to receive a projectile, the coupling end sized to and being mated with the base coupling element; and

a retaining insert received within a combustion chamber of the polymeric casing, the retaining insert ensuring engagement between the polymeric casing and the metallic base;

wherein the base includes a plurality of apertures disposed around an arch length of the base and in communication with the combustion chamber of the polymeric casing, and a mechanical fastening member received in each of the plurality of apertures forming a compression assembly between the polymeric casing, the metallic base, and the retaining insert.

12. The polymeric cartridge subassembly of claim 11 , wherein the polymeric casing includes a shoulder portion for couplable engagement with the metallic base forward surface such that a ledge member of the metallic base receives the casing opposite end during subassembly.

13. The polymeric cartridge subassembly of claim 11 , wherein the polymeric casing is formed from a graphene-reinforced polymer matrix composite.

14. The polymeric cartridge subassembly of claim 13 , wherein the graphene-reinforced polymer matrix composite comprises 35% graphite in 65% polyether-ether-ketone (PEEK) polymer that has been fully exfoliated.

15. The polymeric cartridge subassembly of claim 13 , wherein the graphene-reinforced polymer matrix composite comprises 20% graphite in 80% polyphenylene sulfide (PPS) that has been fully exfoliated.

16. The polymeric cartridge subassembly of claim 13 , wherein the graphene-reinforced polymer matrix composite is formed from a thermoplastic selected from the group consisting of: high density polyethylene, polyethylene terephthalate, polystyrene, polyamide 6-6, polysulfone, polyphenylene sulfide, and polyether-ether-ketone.

17. The polymeric cartridge subassembly of claim 11 wherein the forward end opening includes at least one protrusion on an interior surface.

18. The polymeric cartridge subassembly of claim 17 , wherein the at least one protrusion comprises an Acme thread pattern and a tear perf at a root of the Acme thread pattern.

19. A method of assembling a polymeric cartridge for use in medium caliber weaponry, the method comprising the steps of:

securing a coupling end of a polymeric casing to a coupling element of a metallic base such that the coupling element encapsulates an interior combustion chamber of the polymeric casing;

inserting a primer into a primer recess of the base;

inserting a propellant charge within the combustion chamber;

seating a projectile onto a forward end opening of the polymeric casing to encapsulate the combustion chamber, wherein the polymeric casing is formed from a graphene-reinforced polymer matrix composite;

inserting a retaining insert within the combustion chamber;

securing a mechanical fastening member within each of a plurality of apertures disposed on an arch length of the base such that the mechanical fastening member is received by the retaining stamping and the base; and

forming a compression assembly between the casing, the base, and the retaining insert.

20. The method of claim 19 , wherein the projectile comprises a medium caliber projectile.

21. The method of claim 19 , wherein the forward end opening includes at least one protrusion on an interior surface to ensure a contact point with the projectile and a predetermined cartridge overall length elevation during assembly.