| CPC F42B 33/001 (2013.01) [B21D 37/10 (2013.01); F42B 12/06 (2013.01)] | 20 Claims |
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1. A multi-stage process of forming a bullet of a predetermined caliber, the process comprising:
providing a multi-stage die assembly, each stage of the assembly comprising: a stationary die comprising a die cavity extending from a first end to a second end and defining a cavity diameter, a punch configured to press into the first end of the die, and an eject stem defining a stem diameter, the eject stem configured to extend into the second end of the die;
in one or more preliminary stages:
forming a rear component comprising: a core, a jacket comprising a cylindrical jacket body portion extending axially forward of the core, a tapering boat tail shape rearward of the jacket body portion, and a rear face defining a base diameter,
the jacket body portion defining an inner jacket diameter and an outer jacket diameter, the outer jacket diameter being substantially equal to the predetermined caliber of the bullet;
in a loose-fit stage:
placing the rear component in the die with the rear face toward the second end of the die, and
assembling the bullet by inserting a penetrator into the jacket via the punch applying a loose-fit force on the penetrator, the penetrator comprising: a base defining a penetrator diameter sized to press-fit relative to the inner jacket diameter, an ogive portion tapering in diameter from the base, and a forward tip;
in a press-fit stage:
placing the bullet in the die with the rear face toward the second end of the die,
seating the penetrator fully against the core by the punch applying a press-fit force to the penetrator, the press-fit force being greater than the loose-fit force,
radially expanding the jacket in response to the press-fit force, the expanded outer jacket diameter being greater than the predetermined caliber, and
supporting an annulus of the rear face of the rear component against the die, the die of the press-fit stage comprising a ledge extending radially inwardly to engage the annulus of the rear face; and
in a jacket-forming stage:
placing the bullet in the die with the rear face toward the second end of the die,
decreasing the outer jacket diameter via the punch applying a jacket-forming force, and
pressing a forward portion of the jacket against the ogive portion of the penetrator,
in one or more finishing stages:
placing the bullet in the die with the rear face toward the second end of the die, and
the punch applying force to one or more of: the forward tip of the penetrator, the ogive portion of the penetrator, and the forward portion of the jacket,
wherein, in the press-fit stage, the stem diameter is less than the stem diameter in at least one of the loose-fit stage and the jacket-forming stage.
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