Bullet with spherical nose portion

• US 7,487,727 B2
• Filed: 06/18/2004
• Issued: 02/10/2009
• Est. Priority Date: 11/09/2001
• Status: Expired due to Term

• Current Assignee: OLIN Corporation
• Original Assignee: OLIN Corporation
• Inventors: Hayes, Richard A., Eberhart, Gerald T.
• Primary Examiner(s): Parsley; David J
• Application Number:
  US10/872,261
• Publication Number:
  US 20050066845A1
• Time in Patent Office: 1,698 Days
• Field of Search: 73/120.5, 731/67, 102507-510, 102/514, 102/516, 102/519, 86/55
• US Class Current: 102/510
• CPC Class Codes: F42B 12/34 expanding before or on impact, i.e. of dumdum or mushroom type
• CPC Class Codes: F42B 12/74 of the core or solid body

Abstract

A bullet includes a frontward facing aperture. Contained within the aperture is a relatively hard bullet frontal element that provides advantageous bullet impact performance. In one embodiment, the frontal element is a steel sphere that provides advantageous penetration and weight retention when the bullet impacts laminated glass, such as an automobile windshield.

Claims

1. A method for defeating a barrier utilizing a bullet having a body having a diameter between 0.22 and 0.50 inch (0.56 and 1.27 cm) and a spherical frontal element accommodated at least partially within a front compartment and having a specific gravity of at least 2.5, said method comprising:

forming said bullet to have a generally cylindrical rear portion and an ogival front portion that terminates at a forward rim, said ogival front portion having a profiled side wall that defines a coaxial front compartment extending inwardly from said forward rim and terminating at a rear surface, said side wall having a profiled thickness that is thin at the forward rim and gradually increased in thickness towards the rear surface of the front compartment, said thin wall thickness at the forward rim being configured to provide expansion at low impact velocities, and said increased thickness being configured to resist fragmentation of material from the bullet;

locating said spherical frontal element at least partially in said front compartment whereby on impact said spherical frontal element has initial contact with said barrier; and

impacting the bullet against the barrier at a velocity and angle relative to normal so that the frontal element initiates a crushing of an outer of the barrier and permits a full penetration of the barrier by at least 90 percent of an initial mass of the bullet.

2. The method of claim 1 wherein said body, velocity and angle are such that with an otherwise identical alternate bullet having an alternate frontal element of identical diameter to said frontal element and consisting essentially of polycarbonate when so impacted against such a barrier less than 90 percent of an initial mass of such alternate bullet would fully penetrate the barrier as a unit.

3. The method of claim 1 wherein the barrier is a laminated glass barrier.

4. The method of claim 3 wherein the spherical frontal element is steel.

5. The method of claim 4 wherein the spherical frontal element has a hardness in excess of 60 DPH.

6. The method of claim 3 wherein the laminated glass barrier is laminated automobile safety glass.

7. The method of claim 6 wherein the laminated automobile safety glass is one quarter inch thick.

8. A method for defeating a laminated glass barrier comprising:

providing a bullet comprising;

a body having a diameter between 0.22 and 0.50 inch (0.56 and 1.27 cm), a profiled side wall that defines a front compartment, and a spherical frontal element accommodated at least partially within front compartment and having a specific gravity of at least 2.5, the side wall having a profiled thickness that is thin at the forward rim and gradually increased in thickness towards the rear surface of the front compartment, said thin wall thickness at the forward rim being configured to provide expansion at low impact velocities, and said increased thickness being configured to resist fragmentation of material from the bullet; and

impacting the bullet against the laminated glass barrier at a velocity and angle relative to normal so that the frontal element initiates a crushing of an outer glass layer of the laminated glass barrier and permits a full penetration of the laminated glass barrier by at least 90 percent of an initial mass of the bullet.

9. The method of claim 8 wherein the spherical frontal element is steel.

10. The method of claim 9 wherein the spherical frontal element has a hardness in excess of 60 DPH.

11. The method of claim 8 wherein the laminated glass barrier is laminated automobile safety glass.

12. The method of claim 11 wherein the laminated automobile safety glass is one quarter inch thick.