 The 5½" barrel models were called the "Artillery," and the "Cattleman" or "Cowboy" models.And, 7½" barrel models were called the "Army", the "Cavalry" and the "Standard" models.The British Bull Dog was a popular type of 5-shot, solid-frame, double action, pocket revolver introduced by Philip Webley & Son of Birmingham, England, in 1872, and subsequently copied by gunmakers in continental Europe and the United States.