US20160356584A1

US20160356584A1 - Expanding bullets

Info

Publication number: US20160356584A1
Application number: US15/170,546
Authority: US
Inventors: Jonathan Ryan Monroe; Michael Eugene Stock
Original assignee: Olin Corp
Current assignee: Olin Corp
Priority date: 2015-06-02
Filing date: 2016-06-01
Publication date: 2016-12-08
Also published as: WO2017027086A2; WO2017027086A3

Abstract

An expanding bullet has a core having a proximal end, a distal end, and a sidewall therebetween. A tip is positioned at the distal end of the core, and has a generally conical distal section, and a generally cylindrical proximal section defining a proximally facing shoulder at their juncture. A jacket having a generally cylindrical proximal portion surrounding at least a portion of the core adjacent its proximal end, and a distal portion that tapers to an open end, the distal portion surrounding the distal portion of the core and the proximal section of the tip, with the distal end of the jacking abutting the shoulder on the tip to form a smooth tapering ogival surface with the tip. The maximum diameter of the tip preferably comprises a substantial portion (preferably at least about 65%) of the diameter of the bullet.

Description

CROSS-REFERENCED APPLICATION

This application claims priority to U.S. provisional application Ser. No. 62/170,118 filed on Jun. 2, 2015. The disclosure of the above-referenced application is incorporated herein by reference in its entirety.

FIELD

The present disclosure relates to expanding bullets.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.
This invention relates to bullets, and in particular to fast-expanding hunting bullets that expand upon impact with a target, creating a more effective wound channel.
There is a wide variation in bullet designs to achieve various desirable attributes, such as stable flight and in-target performance. One common bullet is the hollow point bullet, which typically comprises a core of a soft material such as lead or a lead alloy with a tapering open ended jacket of a harder material, such as copper or a copper alloy. This configuration allows the bullet to expand upon entering a target. Rifle bullets of this type will often also have a tapered polymeric tip to improve the aerodynamics of the bullet, which can be important for bullets fired at high velocities or over long distances. Typically, because the tip is provided solely for aerodynamics, and has no significant function on in-target performance of the bullet, this tip is made as small as possible while still providing a smooth, aerodynamic transition from the jacket ogive to a tip.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
Embodiments of the present invention provide expanding hollow point bullets with improved in-target performance. Bullets of the preferred embodiments more quickly expand in the target, providing more destruction and energy transfer than conventional hollow point bullets. Generally, a preferred embodiment of the expanding hollow point hunting bullet comprises a core having a proximal end, a distal end, and a sidewall therebetween, and a tip having a generally conical distal section, and a generally cylindrical proximal section defining a proximally facing shoulder at their juncture. A jacket has a generally cylindrical proximal portion surrounding at least a portion of the core adjacent its proximal end. The jacket also has a distal portion that tapers to an open end. The distal portion surrounds the distal portion of the core as well as the proximal section of the tip, with the distal end of the jacket abutting the shoulder on the tip to form a smooth tapering ogival surface with the tip. The diameter of the tip is preferably at least about 65% of the diameter of the bullet.
The core is preferably made of a malleable metal or metal alloy, such as lead of a lead alloy. The jacket is preferably made of a harder material than the core, such as copper or copper alloy. The tip is preferably made from a polymeric material, such as polycarbonate.
In some embodiments, the outside diameter of the jacket at the distal end of the core is substantially same as the inside diameter of the jacket at the cylindrical section. The proximal end of the tip abuts the distal end of the core. The jacket tapers from the proximal end of the distal section to the distal end of the jacket.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 is a longitudinal cross sectional view of a preferred embodiment of 7 mm expandable hollow point bullet in accordance with a preferred embodiment of this invention;

FIG. 2 is a longitudinal cross sectional view of a preferred embodiment of .30 caliber expandable hollow point bullet in accordance with a preferred embodiment of this invention;

FIG. 3 is a longitudinal cross sectional view of a preferred embodiment of .277 caliber expandable hollow point bullet in accordance with a preferred embodiment of this invention; and

FIG. 4 is a longitudinal cross sectional view of a preferred embodiment of .243 caliber expandable hollow point bullet in accordance with a preferred embodiment of this invention.

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

Example embodiments will now be described more fully with reference to the accompanying drawings.
Embodiments of the present invention provide expanding hollow point bullets with improved in-target performance. Preferred embodiments of a bullet in accordance with the principles of this invention are indicated generally as 20, 20′, 20″ and 20′″ in FIGS. 1-4. Each of the bullets 20, 20′, 20″ and 20′″ has an overall length A, an ogival length B, a tip length C, and a maximum tip diameter D. Preferred dimensions for the bullets 20, 20′, 20″ and 20″′ are given in Table 1:

TABLE 1

Preferred Dimensions

	Overall	Ogival	Tip	Maximum	Overall
	Length	Length	Length	Tip Diam-	Tip
Bullet	A	B	C	eter D	Length E

20	(7 mm)	1.288	0.756	0.323	0.190	0.403
20′	(.30 Cal)	1.188	0.692	0.320	0.220	0.400
20″	(.270 Cal)	1.272	0.675	0.323	0.190	0.403
20′″	(.243) Cal)	1.143	0.590	0.236	0.170	0.316

As shown in FIGS. 1-4. the bullets 20, 20′, 20″ and 20′″ comprise heel 22 at the proximal end, a generally cylindrical body 24 adjacent the proximal end, a tapering ogival portion 26 adjacent the distal end, and a tip 28 at the distal end. A cannelure 30 can be formed on the body generally between the generally cylindrical body 24 and the tapering ogival portion 26.
The bullets 20, 20′, 20″ and 20″′ each comprise a core 32, having a proximal end 34, a distal end 36, and a sidewall 38 therebetween. The bullets further comprise a tip 40 having a generally conical distal section 42, and a generally cylindrical proximal section 44 defining a proximally facing shoulder 46 at the juncture between the distal and proximal sections. A jacket 48 has a generally cylindrical proximal portion 50 surrounding at least a portion of the core 32 adjacent its proximal end 34. The jacket 48 also has a distal portion 52 that tapers to an open end 54. The distal portion 52 of the jacket 48 surrounds the distal portion of the core 32 as well as the proximal section 44 of the tip 40, with the distal end of the jacket abutting the shoulder 46 on the tip to form a smooth tapering ogival surface with the tip.
In contrast to conventional bullets, the tip is relatively larger, i.e., the ratio of the diameter of the tip to the diameter of the bullet is larger, and the ratio of the tip length to the ogive length is larger. As a consequence, the bullet expands much sooner than conventional bullets, beginning almost immediately upon impact. This results in increased disruption to the target, particularly in the initial portion of the wound channel.
Additional dimensions of bullets of the four preferred embodiments shown in FIGS. 1-4, and three comparative examples are given in Table 2, it being understood that variations in the dimensions are still within the scope of the invention:

TABLE 2

							%
							Ogive	%
						% area	length	length
	Bullet	Tip	Full	Tip		covered	covered	covered
Bullet Size	OD	OD	Ogive	Ogive	% dia.	by tip	by tip	by tip

.30	Cal	0.3075	0.22	0.692	0.32	71.5	51.2	46.2	26.9
7	mm	0.2835	0.19	0.756	0.323	67.0	44.9	42.7	25.3
.270	Cal	0.2765	0.19	0.675	0.323	68.7	47.2	47.9	25.4
.243	Cal	0.2415	0.17	0.59	0.236	70.4	49.6	40.0	20.6
0.223	Cal	0.223	0.09	0.45	0.115	40.4	16.3	25.6
0.020	Cal	0.203	0.11	0.38	0.137	54.2	29.4	36.1
0.017	Cal	0.172	0.1	0.285	0.14	58.1	33.8	49.1

The maximum diameter of the tip is preferably at least about 65% of the diameter of the bullet, and more preferably at least about 67% of the diameter of the bullet. The maximum cross-sectional area of the tip is preferably at least about 45% of the cross-sectional area of the bullet. Although it depends upon the shape of the ogival portion, the length of the tip is preferably at least about 40% of the length of the ogival portion.
The core 32 is preferably made of a malleable metal or metal alloy, such as lead of a lead alloy. The jacket 48 is preferably made of a harder material than the core 32, such as copper or copper alloy. The tip 30 is made from a polymeric material, such as polycarbonate. The tip 30 could include metal or other filler materials to provide balance or other desirable properties.
In some embodiments, the outside diameter of the jacket 48 at the distal end of the core 32 is substantially same as the inside diameter of the jacket at the cylindrical section. The proximal end of the tip 40 abuts the distal end 36 of the core 32. The jacket tapers from the proximal end of the distal section to the distal end of the jacket.
The action of the bullet with the larger tip is believed related to the energy of the bullet, which is in part related to the weight of the bullet. Table 3 shows the energy in ft-lbs at 200 yards for selected bullets, for selected cartridges that have been found to perform satisfactorily with tip configurations in accordance with the embodiments of this invention.

	TABLE 3

		Energy (ft-lbs) at
	Bullet Size	200 yards

300	WSM	2541
300	Win Mag	2541
30-06	SPRG	2012
308	Win	1867
7	mm Rem Mag	2278
270	Win	2015
270	WSM	2333
243	Win	1408

Table 4 shows the weight ranges and a preferred weight range for the four calibers of the four preferred embodiment, and for three comparative bullets. The bullets of the preferred embodiments preferably have a weight of between about 85 grains and about 185 grains, and more preferably a weight of between about 95 grains and about 150 grains. The bullets of the preferred embodiment are preferably loaded into cartridges that provide sufficient energy at the point of impact so that with the larger tip, the bullet will begin expanding almost immediately after initial impact. For example bullets having the 200 yard energies shown in Table 3, generally will have sufficient energy at the point of impact for most hunting applications to exhibit enhanced expansion from the enlarged tip.

TABLE 4

	Typical Weight	Preferred Embodiment
Bullet Size	Range (Grains)	Weight (Grains)

7	mm	140-160	140
0.30	Cal	120-220	150
0.270	Cal	130-150	130
0.243	Cal	55-95	95
0.223	Cal	35-77	N/A

It is believed by the inventors that the tip configurations in accordance with the principles of this invention expand faster and provide larger wound channels because less of the bullet's energy is depleated opening the jacket. This is reflected in the fact that less energy is required to form the jacket in the die because the jacket does not have to be deformed as much to form an aerodynamic tip.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

Claims

What is claimed is:

1. An expanding rifle bullet, comprising:

a core having a proximal end, a distal end, and a sidewall therebetween;

a tip having a generally conical distal section, and a generally cylindrical proximal section defining a proximally facing shoulder at their juncture;

a jacket having a generally cylindrical proximal portion surrounding at least a portion of the core adjacent its proximal end, and a distal portion that tapers to an open end, the distal portion surrounding the distal portion of the core, and the proximal section of the tip, with the distal end of the jacking abutting the shoulder on the tip to form a smooth tapering ogival surface with the tip, the maximum diameter of the tip is at least about 65% of the diameter of the bullet, the bullet weighing between about 85 grains and about 185 grains.

2. The expanding rifle bullet according to claim 1 wherein the bullet weighs between about 95 grains and about 150 grains.

3. The expanding rifle bullet according to claim 1 wherein the maximum diameter of the tip is at least about 67% of the diameter of the bullet.

4. The expanding rifle bullet according to claim 1 wherein the maximum cross-sectional area of the tip is at least about 45% of the cross-sectional area of the bullet.

5. The expanding rifle bullet according to claim 1 wherein the maximum cross-sectional area of the tip is at least about 50% of the cross-sectional area of the bullet.

6. The expanding rifle bullet according to claim 1 wherein the exposed length of the tip comprises at least about 40% of the length of the ogive.

7. The expanding rifle bullet according to claim 6 wherein the exposed length of the tip comprises at least about 42% of the length of the ogive.

8. The expanding rifle bullet according to claim 1 wherein the exposed length of the tip comprises at least about 20% of the length of the bullet.

9. The expanding rifle bullet according to claim 8 wherein the exposed length of the tip comprises at least about 25% of the length of the bullet.

10. The expanding bullet according to claim 1 wherein the core is made of a malleable metal or metal alloy.

11. The expanding rifle bullet according to claim 10 wherein the core is made of lead of a lead alloy.

12. The expanding rifle bullet according to claim 1 wherein the jacket is made of a harder material than the core.

13. The expanding rifle bullet according to claim 12 wherein the jacket is made of copper or copper alloy.

14. The expanding rifle bullet according to claim 1 wherein the jacket is made of copper or copper alloy.

15. The expanding rifle bullet according to claim 1 wherein the tip is made of a polymeric material.

16. The expanding rifle bullet according to claim 1 wherein the outside diameter of the jacket at the distal end of the core is substantially same as the inside diameter of the jacket at the cylindrical section.

17. The expanding rifle bullet according to claim 1 wherein the proximal end of the tip abuts the distal end of the core.

18. The expanding rifle bullet according to claim 1 wherein the thickness of the jacket tapers from the proximal end of the distal section to the distal end of the jacket.

19. An expanding rifle bullet, comprising:

a malleable metallic core having a proximal end, a distal end, and a generally cylindrical sidewall therebetween;

a jacket having a generally cylindrical proximal portion surrounding at least a portion of the core adjacent its proximal end, and a distal portion that tapers to an open end, the distal portion surrounding the distal portion of the core, and the proximal section of the tip, with the distal end of the jacking abutting the shoulder on the tip to form a smooth tapering ogival surface with the tip, the area of the open distal end of the jacket comprising at least 45% of the area of cross sectional area of the proximal section of the jacket, the bullet having a weight of between about 85 grains and 185 grains.

20. The expanding rifle bullet according to claim 19 wherein the bullet has a weight of between about 95 grains and about 150 grains.