Lead-free tin projectile

• US 6,016,754 A
• Filed: 12/18/1997
• Issued: 01/25/2000
• Est. Priority Date: 12/18/1997
• Status: Expired due to Term

• Current Assignee: OLIN Corporation
• Original Assignee: OLIN Corporation
• Inventors: Buenemann, Morris C. Jr., Enlow, Keith E.
• Primary Examiner(s): TUDOR, HAROLD JAY
• Application Number:
  US08/993,458
• Time in Patent Office: 768 Days
• Field of Search: 102/501, 102/507-510, 102/514-517, 420/557, 420/560, 420/561, 420/562
• US Class Current: 102/516
• CPC Class Codes: F42B 12/74 of the core or solid body

Abstract

There is provided a lead-free projectile suitable for use as a bullet to be fired from a pistol or rifle. The projectile has a metallic jacket enveloping a metallic core. The core is formed from a high purity tin and has deformation properties similar to that of lead based projectiles without the environmental hazards associated with lead.

Claims

1. A lead-free projectile used in a cartridge having a powdered chemical propellant, comprising:

a metallic jacket having an outer surface defining an aerodynamic profile and an inner surface defining at least one cavity; and

said at least one cavity being filled with essentially pure tin having a tin content of at least 99.85%, by weight, a yield strength of 11.0 MPa or less and a hardness of from about 3 to about 5 HB.

2. The lead-free projectile of claim 1 wherein said essentially pure tin has a maximum of 0.1%, by weight, of any one alloying addition.

3. The lead-free projectile of claim 2 wherein a maximum zinc content is less than 0.005%, by weight.

4. The lead free projectile of claim 3, wherein said essentially pure tin contains, by weight,

a maximum of 0.04% antimony,

a maximum of 0.05% arsenic,

a maximum of 0.030% bismuth,

a maximum of 0.001% cadmium,

a maximum of 0.04% copper,

a maximum of 0.015% iron,

a maximum of 0.05% lead,

a maximum of 0.01% sulfur,

less than 0.005% zinc, and

a maximum of 0.01% (nickel+cobalt).

5. The lead-free projectile of claim 3, wherein said metallic jacket is formed from a metal selected from the group consisting of copper, aluminum, copper alloys, aluminum alloys and steel.

6. The lead-free projectile of claim 5 wherein said metallic jacket is formed from a copper-zinc alloy.

7. The lead-free projectile of claim 5 being of a size effective to be fired from a pistol.

8. The lead-free projectile of claim 7, wherein said projectile has a nose portion formed from said essentially pure tin.

9. The lead-free projectile of claim 8 wherein said nose portion includes a rearwardly extending, forwardly open cylindrical cavity.

10. The lead-free projectile of claim 8 wherein said metallic jacket has a centrally disposed partition portion separating a rear cavity and a forward cavity with essentially pure tin being contained within both said rear cavity and said forward cavity.

11. The lead-free projectile of claim 5 being effective to be fired from a rifle.

12. The lead-free projectile of claim 11 wherein said projectile has a nose portion formed from said metallic jacket.

13. The lead-free projectile of claim 12 including at least one cup-shaped insert disposed in said at least one cavity between said essentially pure tin and said nose portion.