POLYMER PROJECTILE HAVING AN INTEGRATED DRIVING BAND

• US 20140318402A1
• Filed: 11/30/2012
• Published: 10/30/2014
• Est. Priority Date: 11/30/2011
• Status: Active Grant

• Current Assignee: General Dynamics OTS Incorporated (General Dynamics Corporation)
• Original Assignee: Alliant Techsystems Incorporated (Northrop Grumman Corporation)
• Inventors: Carlson, Erik K., Edel, Joshua L., Head, Lawrence P.
• Granted Patent: US 9,494,397 B2
• Time in Patent Office: Days
• US Class Current: 102/439
• CPC Class Codes: F42B 12/40 of target-marking, i.e. impact-indicating type F42B12/48, F42B12/50 take precedence
• CPC Class Codes: F42B 12/76 of the casing
• CPC Class Codes: F42B 14/02 Driving bands; Rotating bands F42B14/04 takes precedence
• CPC Class Codes: F42B 30/02 Bullets
• CPC Class Codes: F42B 33/00 Manufacture of ammunition; Dismantling of ammunition; Apparatus therefor F42B5/188 takes precedence; manufacturing processes for hollow charges F42B1/036; manufacture of blasting cartridge initiators F42B3/195
• CPC Class Codes: F42B 5/145 for dispensing gases, vapours, powders, particles or chemically-reactive substances from projectiles F42B12/46

Abstract

A lightweight projectile having an integrated driving band positioned around the exterior of the polymer base of the projectile for engaging the rifling of a barrel to impart spin stabilization to the projectile. The driving band protrudes from the polymer base to minimize the contact between the polymer base and the rifling to reduce friction between the barrel and the projectile as the projectile is fired. The reduced friction allows the lightweight projectile to be propelled with minimal propellant force while still retaining the ballistic advantages of a spin stabilized projectile.

Claims

1. A lightweight projectile in combination with a telescoping casing, the projectile adapted to be fired through a rifled barrel sized for 5.56 NATO ammunition, comprising:

a bullet shaped projectile sized to be fired in barrel for firing traditional 5.56 NATO ammunition, the projectile having a body with a sealed interior space therein with marking media sealed in the space;

the projectile body comprising a frangible polymer cap for releasing the marking media on impact; and

at least one metal driving band extending circumferentially around the projectile body and having an embedded portion inset within the projectile body and a projecting portion extending radially outward, wherein the projecting portion is adapted to engage the rifling of the barrel to impart spin stabilization to the projectile, wherein the driving band comprises metal.

2. The lightweight projectile and casing of claim 1, wherein the projectile is a 5.56 mm projectile and weighs less than 7 grains.

3. The lightweight projectile and casing of claim 2, wherein the driving band comprises a ring shape extending radially in a plane perpendicular to an axis of the projectile, and wherein the embedded portion has the same thickness as the protruding portion.

4. The lightweight projectile and casing of claim 1 wherein the embedded portion is wider than the protruding portion.

5. The lightweight projectile and casing of claim 4, wherein the protruding portion and the embedded portion is arranged in one of a T-shape and a L-shape when viewed in cross section.

8. The lightweight projectile and casing of claim 1, wherein the protruding portion comprises a flexible material such that a portion of the protruding portion folds over upon engagement by the rifling of the barrel.

9. The lightweight projectile of claim 1, wherein the frangibile polymer cap cooperating engages a polymer projectile.

10. The lightweight projectile of claim 1, wherein the driving band is formed of one of copper and brass.

11. The lightweight projectile of claim 1, wherein the frangible cap has a second driving band to prevent engagement of the polymer base by the rifling as the projectile travels down the barrel.

12. The lightweight projectile base of claim 9, wherein the driving band is positioned at a juncture between the cap and base.

14. The lightweight projectile of claim 1, wherein the driving band is adjacent to an outwardly protruding polymer rib extending from the projectile body.

6-7. -7. (canceled)

13. (canceled)

15. (canceled)

16. A cartridge for firing a lightweight projectile from a conventional firearm having a rifled barrel, comprising:

a lightweight projectile comprising;

a polymer projectile body comprising a cap and a base, the body adapted to rotate around a longitudinal axis;

at least one driving band defined radially around the projectile base having an embedded portion inset within the projectile base and a projecting portion extending radially outward from the longitudinal axis, wherein the projecting portion is adapted to engage the rifling of the barrel to impart spin stabilization to the projectile, the driving band formed of a material different than that of the projectile base.

a cartridge casing comprising an elongated hollow base defining a first opening, a second opening and a reduced diameter portion between the first opening and second opening;

an polymer insert insertable into the first opening and defining a seating portion for receiving a portion of the lightweight projectile, wherein the driving band engages the polymer insert to limit the extent to which the projectile is insertable into the polymer insert; and

a primer positioned proximate to the second opening of the cartridge casing and adapted to generate a quantity of gas when ignited, wherein the reduce diameter portion forms the generated gases into a gas jet to propel the projectile out of the seating portion of the polymer insert.

17. The cartridge of claim 16, wherein the casing further comprises:

a telescoping insert insertable into the second opening of the cartridge casing elongated hollow base and defining a channel for receiving the primer, wherein the channel conveys gases generated by igniting the primer toward the reduced diameter portion, wherein gases generated by the primer also extend the telescoping insert out of the second opening of the cartridge casing.

18. The cartridge of claim 16, wherein the at least one driving band comprises a flat band.

20. The cartridge of claim 16, wherein the at least one driving band comprises a material selected from a group consisting of gilding metals, rigid polymers and metal impregnated polymers.

19. (canceled)

21. A method for reducing friction between a lightweight projectile weighing less that 5 grains and having an exterior surface and comprising a polymer and a rifled barrel of a firearm, comprising:

forming at least one driving band from copper or brass; and

positioning the at least one driving band so that it extends around the exterior surface of the projectile, wherein the driving band protrudes radially outwardly from the exterior surface of the projectile such that the driving band is engagable by the rifled barrel to impart spin to projectile.

22. The method of claim 21 further comprising putting the driving band in a mold before injection molding the polymer of the projectile.

23. A method for reducing friction between a lightweight projectile having an exterior surface and comprising a polymer and a rifled barrel of a firearm, comprising:

forming at least one driving band from copper or brass; and

positioning the at least one driving band in a mold for a component of the projectile;

injecting polymer into the mold so that the driving band is partially embedded into the component of the projectile and so that the driving band extends around the exterior surface of the component, and wherein the driving band protrudes radially outwardly from the exterior surface of the component such that the driving band is engagable by the rifled barrel to impart spin to projectile.

24. The method of claim 23 further comprising assembling the component with another component after putting marking material into the component or the another component.

25-42. -42. (canceled)