Reduced friction expanding bullet with improved core retention feature and method of manufacturing the bullet

摘要

A low-cost, reduced friction expanding bullet with an improved core retention feature and a method of manufacturing the bullet is described wherein a cylindrical jacket containing a compacted malleable metal core having an open end and a closed end is forced into a forming die having a bottleneck shaped interior resulting in a bottleneck shaped pre-form wherein the outside diameter of the open-ended forward portion of the jacket is smaller than the outside diameter of its closed rearward portion and wherein a transition shoulder separates the two diameters. The pre-form is then placed in a profile die wherein a base punch exerts an axial force against said pre-form which axially collapses a portion of the jacket wall forward of the transition shoulder subsequently forcing said portion of the jacket wall radially inwardly providing a reduction in bearing surface and forming an internal core-locking radius while at the same time forming an ogival bullet nose. The bullet thus formed provides reduced friction and ultimately higher muzzle velocity per any given chamber pressure level while also providing a core-locking feature comprising a wide-area, circumferential indentation which serves as a living hinge that ultimately expedites uniform bullet expansion.

主权项

1. An expanding multi-component bullet comprising:
a malleable metal core having a first end and a second end; a metal jacket surrounding the malleable core, the jacket having a wall, a first end defining an ogive portion therealong, and a second end; and a core retention feature formed along a shank portion of the jacket adjacent the ogive portion and configured to retain the malleable core within the jacket upon impact and expansion of the core and jacket, the core retention feature comprising an axially collapsed circumferential depression extending into the wall of the jacket and forming a mating circumferential depression in the malleable core, wherein the circumferential depression defines a hinge area located rearward of the ogive portion and configured to facilitate flexing of the ogive portion to foster expansion of the jacket and malleable core upon impact of the bullet.