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

Abstract

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.

Dependencies are inferred from the claim text.