http://www.navweaps.com/Weapons/WNRussian_16-45_m1914.htm DiGiulian, Tony, Britain: 8"/120 (20.5 cm) sub-caliber Mark I] A weapon of similar concept, the "8-inch sub-calibre Mark II", was converted from a 12-inch gun (either Mark XI, XI*, or XII), producing a 205 mm /75 calibre weapon.