The British adopted a new fully-jacketed projectile, the Mark VI, in January 1904. Gotta research “zip guns”. This advantage was even more significant as the transition to smaller cartridges coincided with the transition from single-shot rifles to manually-operated repeaters, predominately bolt-actions. Dum Dums come in different flavors - the explosive bullets MI spoke of, the wooden bullets supposedly used by the Japanese (actually intent was to have it disintegrate after short flight for close quarter fighting) as well as mercury filled rounds and flat heads. Professor Alexander Ogston of the Surgical Department of the University of Aberdeen was a major critic of von Bruns’ papers. The infamous bullet design was created by the Dum Dum Arsenal, located just outside Calcutta. expansion upon impact. British bullet with the jacket nose left open to expose the lead core in the hope of increasing effectiveness. Photograph courtesy of Photos of the Great War website,