Method of making a colored projectile
View Patent ↗A method of making a colored projectile is disclosed, as well as the projectile made thereby. In an embodiment, the method comprises mechanically plating a colored metal, typically in powdered form, onto the surface of a projectile, such as a frangible, copper-based bullet, a full metal jacket bullet or a total metal jacket bullet. The disclosed plating process imparts a uniform, desired color to the surface of the plated projectile.
1. A method of making a colored projectile, said method comprising:
mechanically plating a metal onto the surface of the projectile, wherein said plating comprises:
adding the projectile to a container comprising an aqueous slurry comprising at least one acid, at least one plating-assisting agent, and at least one particulate plating metal;
rotating the container to agitate the projectile in said slurry for a time sufficient to plate the particulate plating metal on the surface of said projectile to form a plated projectile;
rinsing the plated projectile; and
treating the rinsed projectile with a composition comprising at least one chromium compound, water-soluble polymer and dyes to the surface of said projectile.
2. The method of claim 1 , wherein said projectile is pre-treated prior to plating to clean the surface of unwanted contaminants chosen from oils, oxides, scale, and combinations thereof.
3. The method of claim 2 , wherein pre-treatment comprises placing the projectile in at least one alkaline based solution, acid based solution, water rinse, or combinations thereof.
4. The method of claim 3 , wherein pre-treatment in an acid based solution occurs in the container used for plating prior to adding at least one plating-assisting agent, or at least one particulate plating metal to the container, wherein the acid based solution comprises at least one acid chosen from sulfuric, hydrochloric and citric acids.
5. The method of claim 1 , wherein the projectile is agitated in a slurry comprising said at least one acid to remove oxides from the surface of the bullet prior to the addition of at least one plating agent, and at least one particulate plating metal.
6. The method of claim 1 , further comprising adding impact media to the container prior to rotating, wherein the impact media comprises a mixture of spherical glass beads ranging in size from 0.3 mm to 5.0 mm.
7. The method of claim 6 , wherein the impact media is added in a substantially equal quantity, by volume, to the projectile.
8. The method of claim 1 , wherein the temperature of the solution in the container ranges from 70° F. to 80° F.
9. The method of claim 1 , wherein the at least one particulate plating metal has a diameter ranging from 3 to 20 microns in diameter.
10. The method of claim 1 , wherein the aqueous slurry used for plating has a pH of 2.0 or less.
11. The method of claim 1 , wherein the at least one plating-assisting agent comprises a coppering agent, an accelerator, a chemical promoter or combinations thereof.
12. The method of claim 1 , wherein the particulate plating metal comprises zinc, tin, copper or aluminum.
13. The method of claim 1 , wherein the composition compound imparts a desired color chosen from red, blue, green, yellow, orange, purple, and combinations thereof.
14. The method of claim 1 , wherein the projectile contains a cohesive microstructure that is substantially free of intermetallics and exhibits a density ranging from 7.0 to 8.2 g/cc.
15. The method of claim 1 , wherein the projectile comprises a frangible metal bullet comprising a compacted mixture of copper powder comprising partially sintered particles that are physically bonded to each other to form a cohesive and ductile microstructure.
16. The method of claim 15 , wherein the frangible metal bullet is lead free.
17. The method of claim 15 , which further comprises a step to cannelure a groove into the frangible metal bullet.
18. The method of claim 1 , wherein the projectile comprises a full metal jacket or a total metal jacket bullet.
19. A method of making a colored frangible bullet, said method comprising:
mechanically plating a metal onto the surface of a frangible metal bullet, the frangible
metal bullet comprising a compacted mixture of copper powder comprising partially sintered
particles that are physically bonded to each other to form a cohesive and ductile microstructure,
wherein said plating comprises:
adding the frangible metal bullet to a container comprising an aqueous slurry comprising at least one acid, at least one plating-assisting agent, and at least one particulate plating metal;
rotating the container to agitate the frangible metal bullet in said slurry for a time sufficient to plate the particulate plating metal on the surface of said frangible metal bullet to form a plated frangible metal bullet;
rinsing the plated frangible metal bullet; and
treating the rinsed bullet with a composition comprising at least one chromium compound, water-soluble polymer and dyes to the surface of said plated frangible metal bullet.
20. A projectile made according to the method of claim 1 , said projectile selected from a frangible bullet, a full metal jacket bullet, or a total metal jacket bullet.