Bullet with spherical nose portion
A bullet includes a frontward facing aperture. Contained within the aperture is a relatively hard bullet frontal element that provides advantageous bullet impact performance. In one embodiment, the frontal element is a steel sphere that provides advantageous penetration and weight retention when the bullet impacts laminated glass., such as an automobile windshield.
1. A method for manufacturing a bullet, comprising the steps of:
providing a metallic precursor;
impact extruding the metallic precursor to form a body comprising a rear portion defining a heel, and an opposing front compartment;
inserting a spherical frontal element into a die;
inserting the body into the die such that the spherical frontal element is adjacent to the front compartment; and
punching the heel of the body to depress the body in the die and inwardly deform the front compartment to form a nose portion on the body and to engage the spherical frontal element, the engagement being effective to retain the spherical frontal element partially protruding from the front compartment.
2. The method of claim 1 wherein the metallic precursor has a length to diameter ratio of between 0.5 and 3.0.
3. The method of claim 1 wherein the providing step comprises:
cutting a length of metal wire;
consolidating said length to a more cylindrical form; and
annealing the consolidated length to soften it.
4. The method of claim 1 wherein:
the impact extrusion forms a transverse partition separating the front compartment from a rear compartment; and
the method further comprises inserting a rear core into the rear compartment, the rear core having a density higher than a density of the precursor.
5. The method of claim 1 wherein:
the impact extrusion forms the front compartment along a majority of a length of the body; and
the method further comprises inserting a core into the front compartment, the core having a density higher than a density of the metallic precursor and a mass at least half that of the metallic precursor.
6. The method of claim 1 wherein the impact extrusion includes the acts of:
punching a first indentation in a front end of the metallic precursor, the first indentation having a first depth and a first maximum diameter;
punching a second indentation to extend rearward from a base of the first indentation, the second indentation having a second depth and a second maximum diameter, the second depth being greater than the first depth and the second maximum diameter being less than the first maximum diameter; and
coning the punched metallic precursor to smooth a transition between areas defined by the first and second indentations so as to substantially form said front compartment.
7. The method of claim 6 further comprising cutting a plurality of longitudinal grooves in at least a portion of an interior surface defining said front compartment.
8. The method of claim 6 wherein:
the impact extrusion includes providing a rear compartment which includes punching a third indentation in a rear end of the precursor;
the method further comprises inserting a rear core into the rear compartment, the rear core being of a material denser and more deformable than the body.
9. The method of claim 8 wherein:
the third indentation is punched simultaneously with said coning.
10. The method of claim 1 wherein said spherical frontal element has a specific gravity of at least 2.5 and has been processed to have a hardness in excess of 60 DPH.
11. The method of claim 1 wherein said spherical frontal element retains a spheroid shape after engagement in said nose portion.