Polymer jacketed powder core projectile
A method is disclosed for coating a projectile for use in an ammunition cartridge. A polymer jacket is applied to an undersized projectile core of a first standard caliber to bring the outer dimensions of the jacketed projectile into compliance with those of a second, larger caliber projectile. The polymer jacket coating may produce a non-uniform outer diameter of the polymer jacketed projectile and may include a plurality of circular cavities defined therein. The polymer-jacketed projectile may be a bullet for pistol or rifle ammunition, or a pellet, or shot for use in a shotgun shell.
1. A polymer jacketed projectile, comprising:
an undersized core having a first diameter and a first length, wherein the first diameter is equal to a standard diameter for a first caliber projectile and wherein the first length is equal to a standard length for the first caliber projectile;
a jacket covering an outer surface of the undersized core and made from polymer, wherein the jacket forms a second outer diameter and a second outer length, wherein the second outer diameter is equal to a standard diameter for a second caliber projectile and wherein the second outer length is equal to a standard length for the second caliber projectile; and
wherein the jacket has a nonuniformed outer surface and wherein the polymer jacketed projectile has a weight less than a standard weight of the second caliber projectile.
2. The polymer-jacketed projectile of claim 1 , wherein the nonuniformed outer surface is formed by a plurality of dimples defined in the outer surface.
3. The polymer-jacketed projectile of claim 2 , wherein the dimples have a semi-circular shape.
4. The polymer-jacketed projectile of claim 2 , wherein the dimples have a hexagonal shape.
5. The polymer-jacketed projectile of claim 2 , wherein the dimples have a pentagonal shape.
6. The polymer-jacketed projectile of claim 1 , wherein the undersized core is formed from one or more metal powders.
7. The polymer-jacketed projectile of claim 6 , wherein the metal powder is a high density tungsten metal powder.
8. The polymer-jacketed projectile of claim 6 , wherein the metal powder further comprises one or more fillers.
9. The polymer-jacketed projectile of claim 8 , wherein the filler is an aluminum filler material.
10. The polymer-jacketed projectile of claim 1 , wherein the first caliber projectile is a 7 mm caliber projectile and wherein the second caliber projectile is a .308 caliber projectile.
11. The polymer-jacketed projectile of claim 1 , wherein the undersized core has a first end defining an ogive region and a second opposite end with a boat tail.
12. The polymer-jacketed projectile of claim 11 , wherein the jacket has an ogive region corresponding to the ogive region of the undersized core and a boat tail corresponding to the boat tail of the undersized core.
13. The polymer-jacketed projectile of claim 1 , wherein the jacket forms a hollow point at a tip-end of the projectile.
14. The polymer-jacketed projectile of claim 1 , wherein the jacket forms a rounded nose at a tip-end of the projectile.
15. The polymer-jacketed projectile of claim 1 , wherein the projectile comprises a pellet.
16. The polymer-jacketed projectile of claim 1 , wherein the projectile comprises a ball.
17. A method for manufacturing a polymer-jacketed projectile, comprising:
preforming an undersized core from one or more metal powders by metal injection molding, wherein the undersized core has a first diameter and a first length which are equal to a standard diameter and standard length for a first caliber projectile; and
molding a jacket, composed of one or more polymers, over the undersized core to form a polymer jacket with a nonuniformed outer surface, wherein the polymer jacket has a second diameter and a second length which are equal to a standard diameter and a standard length for a second caliber projectile, wherein the polymer-jacketed projectile has a weight that is less than a standard weight of the second caliber projectile.
18. The method of claim 17 , wherein the preforming step further comprises placing the undersized core in a first die to form a boat tail.
19. The method of claim 17 , wherein the preforming step further comprises placing the undersized core in a second die to form an ogive region.
20. The method of claim 17 , wherein the nonuniformed outer surface of the molded jacket comprises a plurality of dimples each having a semi-circular shape.