Polymer jacked solid core projectile

Patent metadata

Field	Value
Publication number	US-12460909-B2
Application number	US-202418591395-A
Country	US
Kind code	B2
Filing date	Feb 29, 2024
Priority date	Feb 29, 2024
Publication date	Nov 4, 2025
Grant date	Nov 4, 2025

Abstract

Provided is a polymer jacketed projectile with metal core. The projectile includes a metal bullet core and a monolithic polymer bullet jacket surrounding a portion of the bullet core. The jacket includes a series of radial driving bands cut into the jacket in a graduated configuration at increasing thicknesses. The graduation and increasing thickness of the driving bands allows gradual radial acceleration upon engraving of the rifling due to intentional radial deformation of the forward driving bands. Additionally, the bullet core) includes high-friction surfaces formed in a longitudinal direction or at a base of the bullet core. The modified surface increases friction between the bullet core and polymer, further decreasing radial slippage.

First claim

The invention claimed is:

1 . A firearm projectile comprising:
a bullet core comprising a high-friction surface formed from nose to tail in a longitudinal direction or at a base of said bullet core; and a monolithic polymer bullet jacket surrounding a portion of said bullet core and comprising a series of radial driving bands cut into said jacket in a graduated configuration at progressively increasing width from nose to tail.

2 . The firearm projectile of claim 1 , further comprising a high-temperature adhesive to bond said bullet core to said polymer jacket.

3 . The firearm projectile of claim 1 , wherein said monolithic polymer bullet jacket is constructed from nylon, radel, or a carbon containing polymer.

4 . The firearm projectile of claim 1 , further comprising an ablative material positioned behind said bullet core to act as an ablative that will protect the bore of the firearm from erosion while also reducing gas temperature and/or consuming any oxidizing compounds.

5 . The firearm projectile of claim 1 , further comprising a wax or ablative positioned behind said bullet core.

6 . The firearm projectile of claim 1 , further comprising a wax or ablative positioned in a pocket in the rear of the projectile.

7 . The firearm projectile of claim 1 , further comprising a boat tail with an anti-slip feature to increase friction between said bullet core and said bullet jacket.

8 . The firearm projectile of claim 1 , wherein a forward most driving band makes contact with rifling in a barrel, swages and undergoes radial deformation and initiates radial acceleration or rotation of the projectile.

9 . The firearm projectile of claim 8 , wherein a second driving band makes contact with said rifling in said barrel, swages and undergoes radial deformation and causes radial acceleration to increase due to the additional thickness of said second driving band.

10 . The firearm projectile of claim 9 , wherein radial acceleration continues to increase as remaining driving bands make contact with said rifling.

11 . A firearm projectile comprising:
a bullet core comprising a high-friction surface formed from nose to tail in a longitudinal direction or at a base of said bullet core; and a monolithic polymer bullet jacket surrounding a portion of said bullet core and comprising a series of radial driving bands cut into said jacket in a graduated configuration at progressively increasing width from nose to tail; wherein a forward most driving band makes contact with rifling in a barrel, swages and undergoes radial deformation and initiates radial acceleration or rotation of the projectile; wherein a second driving band makes contact with said rifling in said barrel, swages and undergoes radial deformation and causes radial acceleration to increase due to the additional thickness of said second driving band; wherein radial acceleration continues to increase as remaining driving bands make contact with said rifling.

12 . The firearm projectile of claim 11 , further comprising a high-temperature adhesive to bond said bullet core to said polymer jacket.

13 . The firearm projectile of claim 11 , wherein said monolithic polymer bullet jacket is constructed from nylon, radel, or a carbon containing polymer.

14 . The firearm projectile of claim 11 , further comprising an ablative material positioned behind said bullet core to act as an ablative that will protect the bore of the firearm from erosion while also reducing gas temperature and/or consuming any oxidizing compounds.

15 . The firearm projectile of claim 11 , further comprising a wax or ablative positioned behind said bullet core.

16 . The firearm projectile of claim 11 , further comprising a wax or ablative positioned in a pocket in the rear of the projectile.

17 . The firearm projectile of claim 11 , further comprising a boat tail with an anti-slip feature to increase friction between said bullet core and said bullet jacket.

Assignees

• Us Navy

Inventors

• Harris Michael R
• Armstrong David P
• Burkart Joseph T
• Taylor Iv Lucius A

Classifications

• F42B12/78

  of jackets for smallarm bullets {; Jacketed bullets or projectiles} · CPC title

• F42B14/06

  Sub-calibre projectiles having sabots; Sabots therefor · CPC title

• F42B30/02

  Bullets · CPC title

• F42B14/02 Primary

  Driving bands; Rotating bands (F42B14/04 takes precedence) · CPC title