Bullet with controlled fragmentation

• US 9,121,677 B2
• Filed: 11/04/2013
• Issued: 09/01/2015
• Est. Priority Date: 09/23/2013
• Status: Active Grant

• Current Assignee: Hornady Manufacturing Company
• Original Assignee: Hornady Manufacturing Company
• Inventors: Emary, David E.
• Primary Examiner(s): TILLMAN, JR, REGINALD S
• Application Number:
  US14/071,351
• Publication Number:
  US 20150083011A1
• Time in Patent Office: 666 Days
• Field of Search: 102506-510, 102514-516
• US Class Current: 1/1
• CPC Class Codes: F42B 12/02 characterised by the warhead or the intended effect
• CPC Class Codes: F42B 12/24 with grooves, recesses or other wall weakenings F42B12/26, F42B12/28 take precedence
• CPC Class Codes: F42B 12/34 expanding before or on impact, i.e. of dumdum or mushroom type
• CPC Class Codes: F42B 12/78 of jackets for smallarm bullets ; Jacketed bullets or projectiles
• CPC Class Codes: F42B 14/02 Driving bands; Rotating bands F42B14/04 takes precedence

Abstract

A bullet with controlled fragmentation has a core in the form of a generally cylindrical body having a forward end and a rear end and intermediate side portions extending there between, the forward end of the core defining a cavity, a jacket encompassing the rear end and at least selected portions of the sides of the core, the jacket having a sidewall having a first drive band portion having a first wall thickness, and a second portion immediately forward of the drive band portion having a second thickness less than the first thickness, the exterior of the jacket defining a cannelure groove encircling the bullet, and the cannelure groove being positioned forward of the first drive band portion. The drive band may have forward edge defining a step. The bullet of the present invention may also be received in the case mouth of a rimless case and be partially protruding therefrom.

Claims

1. A jacketed hollow-point bullet comprising:

a core having a forward end and a rear end and intermediate side portions extending therebetween;

the forward end of the core defining a cavity;

a jacket encompassing the rear end and at least selected portions of the sides of the core;

the jacket having a sidewall having a first portion having a first wall thickness, and a second portion immediately forward of the first portion having a second wall thickness less than the first wall thickness;

the first portion having forward edge defining a step;

the exterior of the second portion of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned adjacent to the first portion of the jacket sidewall; and

wherein the cannelure has a rear limit forward of the step by less than the first wall thickness.

2. The bullet of claim 1 wherein the second portion of the jacket defines a bulge associated with the cannelure.

3. The bullet of claim 2 wherein a rear portion of the bulge forms an acute angle with respect to the step.

4. The bullet of claim 1 wherein the cannelure has a depth of greater than 40 percent of the width of the cannelure.

5. The bullet of claim 1 wherein the cannelure has a depth of at least 70 percent of wall thickness in which the cannelure is formed.

6. The bullet of claim 1 wherein the core is primarily lead, and has an antimony content of at least 3 percent.

7. The bullet of claim 1 further comprising:

the interior of the jacket defining a bulge associated with the cannelure; and

the bulge being positioned adjacent to the first portion of the jacket sidewall.

8. The bullet of claim 1 wherein the core is in the form of a generally cylindrical body.

9. A jacketed hollow-point bullet comprising:

a core having a forward end and a rear end and intermediate side portions extending therebetween;

the forward end of the core defining a cavity;

a jacket encompassing the rear end and at least selected portions of the sides of the core;

the jacket having a sidewall having a first portion having a first wall thickness, and a second portion immediately forward of the first portion having a second wall thickness less than the first wall thickness;

the first portion having forward edge defining a step;

the exterior of the second portion of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned adjacent to the first portion of the jacket sidewall; and

wherein the cannelure has a rear limit forward of the step by less than the second wall thickness.

10. A jacketed hollow-point bullet comprising:

a core having a forward end and a rear end and intermediate side portions extending therebetween;

the forward end of the core defining a cavity;

a jacket encompassing the rear end and at least selected portions of the sides of the core;

the jacket having a sidewall having a first portion having a first wall thickness, and a second portion immediately forward of the first portion having a second wall thickness less than the first wall thickness;

the first portion having forward edge defining a step;

the exterior of the second portion of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned adjacent to the first portion of the jacket sidewall; and

wherein the cannelure has a rear limit forward of the step by less than the width of the cannelure.

11. A jacketed hollow-point bullet comprising:

a core having a forward end and a rear end and intermediate side portions extending therebetween;

the forward end of the core defining a cavity;

a jacket encompassing the rear end and at least selected portions of the sides of the core;

the jacket having a sidewall having a first portion having a first wall thickness, and a second portion immediately forward of the first portion having a second wall thickness less than the first wall thickness;

the first portion having forward edge defining a step;

the exterior of the second portion of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned adjacent to the first portion of the jacket sidewall; and

wherein the step joins the inner surface of the second portion of the jacket at an interior junction, and wherein the cannelure has a rear wall and a floor surface joining at a rear cannelure junction, and wherein a line connecting the interior junction to the rear cannelure junction forms greater than a 45 degree angle with respect to a primary central axis of the bullet.

12. A jacketed hollow-point bullet comprising:

a core having a forward end and a rear end and intermediate side portions extending therebetween;

the forward end of the core defining a cavity;

a jacket encompassing the rear end and at least selected portions of the sides of the core;

the jacket having a sidewall having a first portion having a first wall thickness, and a second portion immediately forward of the first portion having a second wall thickness less than the first wall thickness;

the first portion having forward edge defining a step;

the exterior of the second portion of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned adjacent to the first portion of the jacket sidewall; and

wherein the axial distance between the step and a rearmost portion of the cannelure is less than the radial distance between the interior of the second portion of the jacket at the step and the deepest portion of the cannelure.

13. A jacketed hollow-point bullet comprising:

a core having a forward end and a rear end and intermediate side portions extending therebetween;

the forward end of the core defining a cavity;

a jacket encompassing the rear end and at least selected portions of the sides of the core;

the jacket having a sidewall having a first portion having a first wall thickness, and a second portion immediately forward of the first portion having a second wall thickness less than the first wall thickness;

the exterior of the second portion of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned adjacent to the first portion of the jacket sidewall; and

wherein the cavity has a deepest floor portion, and wherein the floor portion is rearward of a forward-most portion of the cannelure.

14. The bullet of claim 13 wherein the floor portion is forward of a rear-most portion of the cannelure.

15. A jacketed hollow-point bullet comprising:

a core having a forward end and a rear end and intermediate side portions extending therebetween;

the forward end of the core defining a cavity;

a jacket encompassing the rear end and at least selected portions of the sides of the core;

the jacket having a sidewall having a first portion having a first wall thickness, and a second portion immediately forward of the first portion having a second wall thickness less than the first wall thickness;

the exterior of the second portion of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned adjacent to the first portion of the jacket sidewall;

the jacket having a sidewall having a first drive band portion having a first wall thickness, and a second portion immediately forward of the drive band portion having a second thickness less than the first thickness;

the exterior of the jacket defining a cannelure groove encircling the bullet;

the cannelure groove being positioned forward of the first drive band portion;

the drive band having forward edge defining a step; and

wherein the cannelure has a rear limit forward of the step by less than the first wall thickness.

16. The bullet of claim 15 wherein the cannelure has a rear limit forward of the step by less than the second wall thickness.

17. The bullet of claim 15 wherein the cannelure has a rear limit forward of the step by less than the width of the cannelure.

18. The bullet of claim 15 wherein the step joins the inner surface of the second portion of the jacket at an interior junction, and wherein the cannelure has a rear wall and a floor surface joining at a rear cannelure junction, and wherein a line connecting the interior junction to the rear cannelure junction forms greater than a 45 degree angle with respect to a primary central axis of the bullet.

19. The bullet of claim 15 wherein the axial distance between the step and a rearmost portion of the cannelure is less than the radial distance between the interior of the second portion of the jacket at the step and the deepest portion of the cannelure.