BL 13.5-inch Mk VI naval gun

The BL 13.5-inch Mk VI gun was a British heavy naval gun, originally ordered by the Ottoman Navy to equip its dreadnoughts around 1911. The one ship completed was seized by the British Government when World War I began in August 1914 and became HMS Erin. Only 10 guns were built by Vickers to a design similar to that of their 45-calibre BL 13.5-inch Mk V naval gun. The smaller chamber in the Mk VI gun meant that less propellant could be used which reduced muzzle velocity by 55 ft/s and range by 630 yd.

Weapons of comparable role, performance and era

 * 340mm/45 Modèle 1912 gun French equivalent