REDUCED FRICTION EXPANDING BULLET WITH IMPROVED CORE RETENTION FEATURE AND METHOD OF MANUFACTURING THE BULLET

摘要

A low-cost, reduced friction expanding bullet (160) with an improved core retention feature (130) and a method of manufacturing the bullet (160) is described wherein a cylindrical jacket (100) containing a compacted malleable metal core (110) having an open end (105) and a closed end is forced into a forming die having a bottleneck shaped interior resulting in a bottleneck shaped pre-form (1 14) wherein the outside diameter of the open-ended forward portion of the jacket (100) is smaller than the outside diameter of its closed rearward portion and wherein a transition shoulder (125) separates the two diameters. The pre-form (114) is then placed in a profile die (148) wherein a base punch exerts an axial force against said pre-form (114) which axially collapses a portion of the jacket wall forward of the transition shoulder (125) 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 (150). The bullet (160) thus formed provides reduced friction and ultimately higher muzzle velocity per any given chamber pressure level while also providing a core-locking feature (130) comprising a wide- area, circumferential indentation (130) which serves as a living hinge (163) that ultimately expedites uniform bullet (160) expansion.