Multi-component bullet with core retention feature and method of manufacturing the bullet
View Patent ↗A three component bullet with an improved core retention feature and a method of manufacturing the bullet includes a cylindrical jacket having an open end and a closed end containing a malleable metal core which is forced into a forming die having a bottleneck shaped interior, wherein the outside diameter of the open-ended forward portion of the jacket is smaller than the outside diameter of its closed rearward portion. The open end of the pre-form may be dropped through or forced through a malleable non-rigid locking band. A relatively tight-fitting punch enters the open end of the pre-form, to radially swell the core and subsequently portions of the jacket fore and aft of the non-rigid locking band, thereby securing the non-rigid locking band in place. An inwardly-extending annular band of jacket material embeds itself into the core material to lock the core inside the jacket.
1. A bullet, comprising:
a malleable core having a section with a first end and a second end;
a jacket surrounding the malleable core, the jacket having a first end and a second end; and
a non-rigid locking band surrounding a portion of the jacket configured to retain the malleable core with the jacket during use, at least a portion of the locking band extending along a circumferential depression in a wall of the jacket and the malleable core;
wherein the locking band comprises a deformable material such that upon impact, the locking band moves away from the circumferential depression, exposing a hinge area defined adjacent the circumferential depression and about which at least a portion of the jacket folds during expansion of the bullet.
2. The bullet of claim 1 , wherein the locking band comprises a plastic material having a reduced weight such that a combined weight of the jacket and the locking band does not exceed 25% of a total bullet weight.
3. The bullet of claim 2 , wherein the locking band comprises a filled or unfilled thermoplastic polymer material.
4. The bullet of claim 3 , wherein the polymer material of the locking band further includes at least one of a reinforcing material comprising approximately 20% to 40% carbon fiber, a hardness range of approximately 95-114 on the Rockwell M scale, or a melting temperature of at least approximately 400° F. or higher.
5. The bullet of claim 2 , wherein the polymer material of the non-rigid locking band further comprises approximately 0.25%-5.0% of a lubricant.
6. The bullet of claim 1 , wherein the locking band comprises a polymer material selected from the group comprising: Polycarbonate, polyetherimide, poly ether ketone, poly phenylene sulfides and oxides, high density polyethylene, polystyrene, polyoxymethylene, and polyamide materials.
7. The bullet of claim 1 , wherein the non-rigid locking band comprises an outside diameter that is equal to or less than an outside diameter of an outermost portion of the bullet.
8. The bullet of claim 1 , wherein the malleable core further comprises a centrally aligned recess formed in the first end of the malleable core.
9. The bullet of claim 1 , wherein an outside diameter of the locking band is substantially equal to or less than an outside diameter of the jacket.
10. The bullet of claim 1 , wherein the locking band has an axial wall height of about 0.075-0.125 inches.
11. The bullet of claim 1 , the jacket further comprising a jacket weakening feature adjacent the first end of the jacket.
12. The bullet of claim 11 , wherein the jacket weakening feature comprises a plurality of longitudinally projecting spaced slits forming a plurality of spaced petals.
13. The bullet of claim 1 , wherein the locking band comprises a metal material, and further comprises a series of weakened areas formed at spaced locations about a circumference of the locking band.
14. A method of manufacturing a bullet, comprising:
filling a jacket with a core material;
applying a non-rigid, deformable band about the jacket;
forming a circumferential depression about the jacket and the core material within the jacket with the non-rigid band being received within the circumferential depression formed in the jacket and the malleable core; and
expanding the core material and jacket adjacent the circumferential depression such that the jacket and the malleable core material are retained together with the non-rigid band positioned within the circumferential depression formed around the jacket;
wherein forming the circumferential depression comprises urging portions of the jacket and malleable core inwardly to define a hinge area at a selected location along the body of the bullet below an ogive portion thereof, whereby upon impact of the bullet, the ogive portion of the bullet folds about the hinge area to facilitate expansion of the bullet.
15. The method of claim 14 , further comprising:
radially expanding the jacket and the malleable core material to form shoulder areas in the jacket adjacent first and second end edges of the non-rigid locking band received within the circumferential depression.
16. The method of claim 14 , further comprising:
configuring jacket-weakening features in an open end of the jacket.
17. The method of claim 14 , wherein applying a non-rigid deformable band about the jacket comprises injection molding a polymer material locking band at an intermediate location along a length of the jacket.