Non-jacketed expandable bullet and method of manufacturing a non-jacketed expandable bullet

1. A non-jacketed expandable bullet, comprising:

a monolithic sintered body comprising:

a base portion having a proximal end and a distal end; and

a deformed hollow nose portion extending distally from the distal end of the base portion,

wherein the base portion has a circular transverse cross-section, a distal portion of the base portion is tapered axially inwardly in a distally extending direction such that a transverse cross-sectional area of the distal portion of the base portion decreases in a direction from the proximal end of the base portion toward the distal end of the base portion, and a proximal portion of the base portion has a constant cross-sectional area,

the deformed hollow nose portion comprises a proximal end, a distal end, and a sidewall between the proximal end and the distal end, and

the sidewall defines an internal cavity and at least a portion of an inner surface of the internal cavity tapers inwardly in a direction extending from the proximal end of the deformed hollow portion toward the distal end of the deformed hollow portion.

2. The non-jacketed expandable bullet of claim 1 , wherein at least a portion of an inner surface of the internal cavity tapers outwardly in a direction extending from the proximal end of the deformed hollow portion toward the distal end of the deformed hollow portion.

3. The non-jacketed expandable bullet of claim 1 , wherein the monolithic sintered body is lead free.

4. The non-jacketed expandable bullet of claim 1 , wherein the monolithic sintered body includes at least one of copper, nickel, tin, zinc, or any combination thereof.

5. The non-jacketed expandable bullet of claim 1 , wherein the monolithic sintered body is made from copper or a copper-based alloy.

6. The non-jacketed expandable bullet of claim 5 , wherein the copper-based alloy includes at least 60% copper.

7. The non-jacketed expandable bullet of claim 5 , wherein the copper-based alloy includes at least one of nickel, tin, zinc, or any combination thereof.

8. Ammunition, comprising:

a non-jacketed bullet according to claim 1 ; and

a cartridge casing holding the non-jacketed bullet.

9. A method of manufacturing a non-jacketed expandable bullet according to claim 1 , the method comprising:

providing a monolithic sintered body comprising:

a base portion having a proximal end and a distal end; and

a hollow peripheral portion extending distally from the distal end of the base portion; and

forming the hollow peripheral portion into a shape of a hollow tapered nose;

wherein the base portion has a circular transverse cross-section, a distal portion of the base portion is tapered axially inwardly in a distally extending direction such that a transverse cross-sectional area of the distal portion of the base portion decreases in a direction from the proximal end of the base portion toward the distal end of the base portion, and a proximal portion of the base portion has a constant cross-sectional area, the deformed hollow nose portion comprises a proximal end, a distal end, and a sidewall between the proximal end and the distal end, and the sidewall defines an internal cavity and at least a portion of an inner surface of the internal cavity tapers inwardly in a direction extending from the proximal end of the deformed hollow portion toward the distal end of the deformed hollow portion.

10. The method of claim 9 , wherein providing the monolithic sintered body comprises:

providing a compacted powder preform comprising:

a base portion having a proximal end and a distal end; and

a hollow peripheral portion extending distally from the distal end of the base portion; and

sintering the compacted powder preform.

11. The method of claim 10 , wherein providing the compacted powder preform includes:

providing a powder to a cavity formed in a die between at least an upper punch and a lower punch; and

pressing the upper and lower punches together to compact the powder.

12. The method of claim 9 , wherein the hollow peripheral portion comprises a first end, a second end, and a sidewall between the first end and the second end.

13. The method of claim 12 , wherein the sidewall defines an internal cavity and at least a portion of the internal cavity has a transverse cross-section that is one of triangular, square, hexagonal, or octagonal.

14. The method of claim 9 , wherein the monolithic sintered body is lead free.

15. The method of claim 9 , wherein the monolithic sintered body includes at least one of copper, nickel, tin, zinc, or any combination thereof.

16. The method of claim 9 , wherein the monolithic sintered body is made from copper or a copper-based alloy.

17. The method of claim 16 , wherein the copper-based alloy includes at least 60% copper.

18. The method of claim 16 , wherein the copper-based alloy includes at least one of nickel, tin, zinc, or any combination thereof.

19. A non-jacketed expandable bullet, comprising:

a monolithic sintered body comprising:

a base portion having a proximal end and a distal end; and

a deformed hollow nose portion extending distally from the distal end of the base portion,

wherein the entire base portion of the monolithic sintered body tapers axially inwardly in a distally extending direction such that a transverse cross-sectional area of the distal portion of the base portion of the monolithic sintered body decreases in a direction from the proximal end of the base portion of the monolithic sintered body toward the distal end of the base portion of the monolithic sintered body;

the deformed hollow nose portion comprises a proximal end, a distal end, and a sidewall between the proximal end and the distal end, and the sidewall defines an internal cavity and at least a portion of an inner surface of the internal cavity tapers inwardly in a direction extending from the proximal end of the deformed hollow portion toward the distal end of the deformed hollow portion.