Method of manufacturing a frangible slug

• US 7,658,137 B1
• Filed: 04/22/2009
• Issued: 02/09/2010
• Est. Priority Date: 02/03/2006
• Status: Active Grant

• Current Assignee: R. Stresau Laboratory, Inc.
• Original Assignee: Stresau West, Inc.
• Inventors: Romero, Michael A.
• Primary Examiner(s): Carone; Michael
• Assistant Examiner(s): Weber; Jonathan C
• Application Number:
  US12/427,986
• Time in Patent Office: 293 Days
• Field of Search: 86/54, 86/55, 102/506, 102/507, 102/502, 102/513, 102/517, 102/520, 102/527, 264/259, 264/267, 264/268, 264/328.18, 264/163, 419/64, 419/65, 419/66
• US Class Current: 86/55
• CPC Class Codes: F42B 12/74 of the core or solid body
• CPC Class Codes: F42B 33/001 Devices or processes for assembling ammunition, cartridges or cartridge elements from parts
• CPC Class Codes: F42B 7/10 Ball or slug shotgun cartridges
• CPC Class Codes: F42B 8/16 containing an inert filler in powder or granular form

Abstract

Methods and articles are provided for frangible slugs. A method of manufacturing a frangible slug includes heating substantially spherical metallic powdered particles, where substantially all of the powdered particles have diameters larger than 125 microns and smaller than 250 microns, to form heated powdered particles. The method includes heating a microcrystalline wax to form a melted wax. The method also includes combining the heated powdered particles with the melted wax to form a liquid mixture. The method further includes filling a payload cavity of a slug container with the liquid mixture to form a liquid mixture payload, where the slug container is configured to retain a solidified frangible payload as the frangible slug until impact with a solid object.

Claims

1. A method of manufacturing a frangible firearm slug, comprising:

holding a firearm slug container with an open end, a closed end, and a payload cavity having a circumferential rib therein in a tooling device that includes a top surface so the open end of the container is even with the top surface of the tooling device;

overfilling the payload cavity with a liquid mixture of powdered particles and a binder at a temperature above a melt point of the binder;

vibrating the tooling device holding the slug container to settle the powdered particles in the liquid mixture toward a bottom of the payload cavity;

cooling the liquid mixture to form a solidified mixture, using the circumferential rib within the payload cavity to retain the solidified mixture inside the payload cavity until impact with a solid object after firing, wherein during impact the frangible payload substantially disintegrates reducing ricochet, wherein a portion of the solidified mixture is outside the payload cavity and above the top surface of the tooling device; and

removing the portion of the solidified mixture that is outside the payload cavity and above the top surface of the tooling device.

2. The method of claim 1, including forming the frangible slug as a composite of a portion of the solidified mixture remaining inside the payload cavity and the slug container.

3. The method of claim 2, wherein forming the frangible slug includes removing the frangible slug from the tooling device.

4. The method of claim 1, including forming the slug container from a rigid material.

5. The method of claim 1, wherein overfilling the top of the payload cavity includes overfilling the liquid mixture above the top of the payload cavity and onto the top surface of the tooling device.

6. The method of claim 1, including using substantially spherically shaped metal particles, wherein substantially all have diameters larger than 125 microns and smaller than 250 microns.

7. The method of claim 1, including using the binder wherein the binder has a melt point from 160 to 200 degrees Fahrenheit.

8. The method of claim 1, including agitating the liquid mixture prior to overfilling the top of the payload cavity to wet substantially all of the powdered particles with the binder.

9. The method of claim 1, where vibrating the tooling device includes using a vibration table to vibrate the tooling device.

10. The method of claim 1, wherein vibrating the tooling device to settle the powdered particles includes the binder floating to the top of the overfilled payload cavity substantially free of the powdered particles.

11. The method of claim 1, wherein removing the portion of the solidified mixture includes drawing a blade of a cutting tool across the top surface of the tooling device, removing an overfill that is outside the payload cavity and above the top surface of the tooling device, and forming a surface on an open end of the top of the payload cavity.

12. The method of claim 1, wherein overfilling the top of the payload cavity with the liquid mixture of powdered particles and the binder at the temperature above the melt point of the binder includes heating the powdered particles to a temperature of at least 190 degrees Fahrenheit.

13. The method of claim 12, wherein overfilling the top of the payload cavity with the liquid mixture of powdered particles and the binder at the temperature above the melt point of the binder includes combining the heated powdered particles with a melted microcrystalline wax.

14. The method of claim 13, wherein combining includes combining the heated powdered particles with the melted microcrystalline wax to form a liquid mixture in which the heated powdered particles form at least 90 percent of a weight of the liquid mixture.

15. The method of claim 1, including forming the slug container from a frangible material.