Three component bullet with core retention feature and method of manufacturing the bullet

A three component bullet with an improved core retention feature and a method of manufacturing the bullet is described including 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 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. The open end of the pre-form may be dropped through or forced through a malleable locking band of appropriate height, diameter and wall thickness. A relatively tight-fitting punch enters the open end of the pre-form generating sufficient axial force against the face of the metal core to radially swell the core and subsequently portions of the jacket fore and aft of the locking band, thereby securing the locking band in place while at the same time producing an inwardly-extending annular band of jacket material which embeds itself into the core material with the result that the core is permanently locked inside the jacket.