A c1856 Beaumont–Adams Revolver in super condition and untouched. The c1856 Beaumont–Adams revover is a black powder, double action percussion revolver. Originally adopted by the British Army in .442 calibre (54 bore, 11.2 mm) in 1856, it was replaced in British service in 1880 by the .476 calibre (11.6 mm) Enfield MK1 revolver.