# US 10,309,756 B2 · Bullet comprising a compacted mixture of copper powder

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- Number: US 10,309,756 B2
- Document ID: US10309756B2
- Status: Granted
- Kind: B2
- Application number: 15/406,003
- Filed: 2017-01-13
- Published: 2017-07-20
- Granted: 2019-06-04
- Earliest claimed: 2016-01-20
- Assignees: SinterFire Inc.
- Applicants: Michael Sloff; Brian Benini; Kevin Geist
- Inventors: Michael Sloff; Brian Benini; Kevin Geist
- Web page: https://patentgrep.com/patent/US10309756B2

## CPC

- F42B 12/74: of the core or solid body
- F42B 5/02: Cartridges, i.e. cases with charge and missile
- F42B 12/367: {Projectiles fragmenting upon impact without the use of explosives, the fragments creating a wounding or lethal effect (practice or training projectiles disintegrating upon impact F42B8/14; projectiles of high-explosive type with fragmentation-hull construction F42B12/22)}
- F42B: EXPLOSIVE CHARGES, e.g. FOR BLASTING, FIREWORKS, AMMUNITION (explosive compositions C06B; fuzes F42C; blasting F42D)

## Abstract

A bullet comprising a compacted mixture of copper powder comprising particles that are physically bonded to each other to form a cohesive and ductile microstructure is disclosed. Methods of making such a bullet through powdered metallurgy techniques, which provide sufficient properties to allow the bullet to be loaded into a cartridge and crimped without fracture are also disclosed. Such bullets have sufficient strength to maintain their integrity during firing but may fragment upon impact and can be formulated lead-free.

## Claims

### Claim 1

A bullet comprising a compacted mixture of a single metal powder comprising at least 98.5% by weight of copper, wherein the single metal powder comprises partially sintered copper particles that are physically bonded to each other via metallic bonds to form a cohesive and ductile microstructure that is substantially free of intermetallic alloys.

### Claim 2 (depends on 1)

The bullet of claim 1, which exhibits a density ranging from 7.0 to 8.2 g/cc.

### Claim 3 (depends on 1)

The bullet of claim 1, further comprising an admixed lubricant.

### Claim 4 (depends on 3)

The bullet of claim 3, wherein said lubricant comprises at least one chosen from molybdenum disulfide, lithium stearate, zinc stearate, carbon, synthetic wax, and a polymer.

### Claim 5 (depends on 4)

The bullet of claim 4, wherein the synthetic wax comprises N,N′ Ethylene Bis-Stearamide or N,N′ Distearoylethylenediamine.

### Claim 6 (depends on 1)

The bullet of claim 1, wherein the bullet is lead free.

### Claim 7 (depends on 1)

The bullet of claim 1, wherein the bullet further comprises at least one component chosen from a heel, driving band, nose, ogive and a meplat.

### Claim 8 (depends on 7)

The bullet of claim 7, wherein the heel further comprises a concave base to aid in compaction in the nose of the projectile.

### Claim 9 (depends on 7)

The bullet of claim 7, further comprising a fixed-fill nose or ogive section.

### Claim 10 (depends on 1)

The bullet of claim 1, which further comprises at least one cannelure groove, a tipped point, a hollow point, boat-tailed, ring, or groove.

### Claim 11 (depends on 1)

The bullet of claim 1, wherein the single metal powder comprises at least 99.5% by weight of copper.