Subsonic small-caliber ammunition and bullet used in same

• US 20110290142A1
• Filed: 04/25/2011
• Published: 12/01/2011
• Est. Priority Date: 05/25/2010
• Status: Abandoned Application

• Current Assignee: Engel Ballistic Research
• Original Assignee: Engel Ballistic Research
• Inventors: Luchini, Chris, Engel, John Whitworth
• Application Number:
  US13/066,780
• Publication Number:
  US 20110290142A1
• Time in Patent Office: Days
• US Class Current: 102/439
• CPC Class Codes: F42B 12/74 of the core or solid body
• 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
• CPC Class Codes: F42B 30/02 Bullets
• CPC Class Codes: F42B 5/16 characterised by composition or physical dimensions or form of propellant charge, with or without projectile, or powder chemical composition C06B; F42B5/24 takes precedence

Abstract

A bullet comprises a casing engaging segment, a rifling leade mating segment, and a tip segment. The rifling leade mating segment has a frusto-conical shape tapering from a first diameter at a first end portion thereof to a second diameter at a second end portion thereof. The rifling leade mating segment extends from a first end portion of the casing engaging segment. The tip segment extends from the second end portion of the rifling leade mating segment. The first diameter is greater than the second diameter.

Claims

1. A bullet, comprising:

a casing engaging segment;

a rifling leade mating segment extending from a first end portion of the casing engaging segment, wherein the rifling leade mating segment has a frusto-conical shape tapering from a first diameter at a first end portion thereof to a second diameter at a second end portion thereof and wherein the first diameter is greater than the second diameter; and

a tip segment extending from the second end portion of the rifling leade mating segment.

2. The bullet of claim 1 wherein:

the tip segment includes a barrel bore engaging portion extending from the second end portion of the rifling leade mating segment; and

the barrel bore engaging portion having a substantially cylindrical shape.

3. The bullet of claim 2 wherein a diameter of the barrel bore engaging portion is substantially the same as the second diameter.

4. The bullet of claim 2 wherein:

the tip segment includes a nose portion and a barrel bore engaging portion extending between the tip portion and the second end portion of the rifling leade mating segment;

the barrel bore engaging portion has a substantially cylindrical shape; and

the nose portion has a substantially hemi-spherical shape.

5. The bullet of claim 4 wherein a diameter of the barrel bore engaging portion is substantially the same as the second diameter.

6. The bullet of claim 1 wherein the rifling leade mating segment has a conical taper of between about 2.4 degrees and 3.2 degrees.

7. The bullet of claim 6 wherein:

the rifling leade mating segment has a length of about 0.2 inches; and

the second diameter is about 0.2 inches.

8. A bullet, comprising:

a jacket drawn from a copper alloy material, wherein the jacket has a casing engaging segment, a rifling leade mating segment, and a tip segment, wherein the rifling leade mating segment linearly tapers from a first diameter at a first end portion thereof to a second diameter at a second end portion thereof, wherein the rifling leade mating segment extends from the first end portion of the casing engaging segment, wherein the tip segment extends from the second end portion of the rifling leade mating segment, wherein the first diameter is greater than the second diameter, wherein the casing engagement segment defines a bearing surface portion of the jacket, wherein the bearing surface portion has a nominal thickness less than about 0.010″

, and wherein the copper alloy material of at least the bearing surface portion of the jacket has a nominal hardness that is substantially greater than an as-drawn hardness of the copper alloy material of the bearing surface portion of the jacket; and

a lead core provided within the jacket

9. The bullet of claim 8 wherein:

the tip segment includes a barrel bore engaging portion extending from the second end portion of the rifling leade mating segment;

the barrel bore engaging portion having a substantially cylindrical shape; and

a diameter of the barrel bore engaging portion is substantially the same as the second diameter.

10. The bullet of claim 9 wherein:

the tip segment includes a nose portion and a barrel bore engaging portion extending between the tip portion and the second end portion of the rifling leade mating segment;

the barrel bore engaging portion has a substantially cylindrical shape; and

the nose portion has a substantially hemi-spherical shape.

11. The bullet of claim 10 wherein:

the rifling leade mating segment has a taper of between about 2.4 degrees and 3.2 degrees

12. The bullet of claim 8 wherein the bearing surface portion of the jacket is at least partially coated with a friction-reducing material composition.

13. The bullet of claim 12 wherein the friction-reducing material composition is molybdenum disulfide.

14. The bullet of claim 13 wherein the bearing surface portion is coated in its entirety with the friction-reducing material composition.

15. The bullet of claim 8 wherein:

the nominal hardness of the copper alloy material of at least bearing surface portion corresponds to a tensile strength of between about 32 ksi and about 44 ksi;

the bearing surface portion of the jacket is at least partially coated with a friction-reducing material composition; and

the bearing surface portion of the jacket has a thickness between about 0.004″ and

about 0.008″

.

16. A round of ammunition configured for providing sufficient energy for cycling a bolt carrier in a rifle having a gas-energized bolt carrier actuation mechanism, comprising:

a small-caliber cartridge casing configured in accordance with an original equipment manufacturer (OEM) specification for the rifle;

a bullet having a casing engaging segment, a rifling leade mating segment, and a tip segment, wherein the rifling leade mating segment has a frusto-conical shape tapering from a first diameter at a first end portion thereof to a second diameter at a second end portion thereof, wherein the rifling leade mating segment extends from the first end portion of the casing engaging segment, wherein the tip segment extends from the second end portion of the rifling leade mating segment, wherein the first diameter is greater than the second diameter, wherein the casing engagement segment defines a bearing surface portion of the bullet engaged within a bullet receiving opening of the small-caliber cartridge casing thereby forming a propellant-receiving cavity within the small-caliber cartridge casing; and

a propellant within the propellant-receiving cavity of the small-caliber cartridge casing, wherein the propellant is configured by a manufacturer thereof for being used in medium caliber ammunition.

17. The round of ammunition of claim 16 wherein:

the bullet has a core made of a metal having lead as its major constituent component and a jacket drawn from metal having copper as its major constituent component;

the bearing surface portion has a nominal thickness less than about 0.010″

; and

the copper alloy material of at least the bearing surface portion of the jacket has a nominal hardness that is substantially greater than an as-drawn hardness of the copper alloy material of the bearing surface portion of the jacket

18. The round of ammunition of claim 16 wherein:

the bullet has a core made of a metal having lead as its major constituent component and a jacket drawn from metal having copper as its major constituent component;

a nominal thickness of the jacket is less than about 0.010″

; and

at least the bearing surface portion of the jacket has a nominal hardness that is substantially greater than an as-drawn hardness of the jacket.

19. The round of ammunition of claim 16 wherein:

the tip segment includes a barrel bore engaging portion extending from the second end portion of the rifling leade mating segment;

the barrel bore engaging portion having a substantially cylindrical shape; and

a diameter of the barrel bore engaging portion is substantially the same as the second diameter.

20. The round of ammunition of claim 16 wherein:

the nominal hardness of the copper alloy material of at least bearing surface portion corresponds to a tensile strength of between about 32 ksi and about 44 ksi;

the bearing surface portion of the jacket is at least partially coated with a friction-reducing material composition; and

the bearing surface portion of the jacket has a thickness between about 0.004″ and

about 0.008″

.