BULLET WITH CONTROLLED FRAGMENTATION

• US 20150083011A1
• Filed: 11/04/2013
• Published: 03/26/2015
• Est. Priority Date: 09/23/2013
• Status: Active Grant

• Current Assignee: Hornady Manufacturing Company
• Original Assignee: Hornady Manufacturing Company
• Inventors: Emary, David E.
• Granted Patent: US 9,121,677 B2
• Time in Patent Office: Days
• US Class Current: 102/506
• 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 in the form of a generally cylindrical body 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 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.

2. The bullet of claim 1 further comprising the drive band having forward edge defining a step.

3. The bullet of claim 2 wherein the cannelure has a rear limit forward of the step by less than the first wall thickness.

4. The bullet of claim 2 wherein the cannelure has a rear limit forward of the step by less than the second wall thickness.

5. The bullet of claim 2 wherein the cannelure has a rear limit forward of the step by less than the width of the cannelure.

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

7. The bullet of claim 6 wherein a rear portion of the bulge forms an acute angle with respect to the step.

8. The bullet of claim 2 wherein the cannelure has a depth of greater than 40 percent of the width of the cannelure.

9. The bullet of claim 2 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.

10. The bullet of claim 2 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.

11. The bullet of claim 1 wherein the cavity has a deepest floor portion, and wherein the floor portion is rearward of a forward-most portion of the cannelure.

12. The bullet of claim 11 wherein the floor portion is forward of a rear-most portion of the cannelure.

13. 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.

14. The bullet of claim 1 wherein the core has a selected diameter at the drive band portion of the jacket, and has a greater diameter rearward of the drive band.

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

16. A cartridge for an auto-loading pistol comprising:

a rimless case having a case mouth;

a bullet received in the case mouth and partially protruding therefrom; and

the bullet defining a circumferential cannelure groove.

17. The cartridge of claim 16 wherein the cartridge is selected from the group of calibers including 9 mm Luger, 40 S&

W, and 45 ACP.

18. The cartridge of claim 16 wherein the case mouth has a circumferential outer corner edge, and wherein the case mouth is crimped into the cannelure groove by a limited amount such that the outer corner edge is exposed in a forward direction for headspacing.

19. The cartridge of claim 18 wherein the bullet has a first diameter immediately forward of the cannelure groove, and wherein the case mouth outer corner edge has a greater second diameter.

20. The cartridge of claim 16 wherein the case mouth is axially offset from the cannelure.