The BL 15-inch Mark I succeeded the BL 13.5-inch Mk V naval gun. It was the first British 15-inch (380 mm) gun design and the most widely used and longest...

The BL 18-inch Mk I naval gun was a breech-loading naval rifle used by the Royal Navy during World War I. It was the largest and heaviest gun ever used...

The BL 6-inch gun Mark VII (and the related Mk VIII) was a British naval gun dating from 1899, which was mounted on a heavy travelling carriage in 1915...

The BL 16-inch Mark I was a British naval gun introduced in the 1920s and used on the two Nelson-class battleships. A breech-loading gun, the barrel was...

The BL 14-inch Mk VII naval gun was a breech loading (BL) gun designed for the battleships of the Royal Navy in the late 1930s. This gun armed the King...

The BL 12 inch Gun Mark X was a British 45-calibre naval gun which was mounted as primary armament on battleships and battlecruisers from 1906. It first...

The Breech Loading 5.5-inch Mk I was a naval gun used by the British Royal Navy during both World Wars. This weapon was developed by Coventry Ordnance...

British BL 6-inch gun Mk XIX was introduced in 1916 as a lighter and longer-range field gun replacement for the obsolescent BL 6-inch gun Mk VII. The majority...

The BL 8 inch guns Mark I to Mark VII were the first generations of British rifled breechloaders of medium-heavy calibre. They were initially designed...

The BL 4-inch Mk IX naval gun was a British medium-velocity naval gun introduced in 1917 as secondary armament on the Renown-class battlecruisers and...

The BL 8 inch gun Mark VIII was the main battery gun used on the Royal Navy's County-class cruisers, in compliance with the Washington Naval Treaty of...

nominally 4.5 inch naval guns, the QF Mk I has an actual calibre of 4.45 inches (113 mm). From the BL Mark I gun of 1916 the 4.7-inch (120 mm) calibre was...

The BL 12-inch Mark VIII naval gun was one of the first large British rifled breech-loading naval guns designed for the higher pressures generated by the...

The BL 4-inch gun Mk VII was a British high-velocity naval gun introduced in 1908 as an anti-torpedo boat gun in large ships, and in the main armament...

The BL 13.5 inch naval gun Mk I ("67-ton gun") was Britain's first successful large breechloading naval gun, initially designed in the early 1880s and...

The BL 6-inch Mark XII naval gun was a British 45 calibre naval gun which was mounted as primary armament on light cruisers and secondary armament on...

end of the War. The gun replaced the BL 8 inch Mk VIII naval gun used on earlier Washington Naval Treaty cruisers. These built-up guns consisted of a tube...

The BL 13.5 inch Mk V gun was a British heavy naval gun, introduced in 1912 as the main armament for the new super-dreadnought battleships of the Orion...

The BL 9.2-inch Mk I–VII guns were a family of early British heavy breechloading naval and coast defence guns in service from 1881 to the end of World...

The BL 10 inch guns Mks I, II, III, IV were British rifled breechloading 32-calibre naval and coast defence guns in service from 1885. The British 10-inch...

The BL 6-inch gun Marks II, III, IV and VI were the second and subsequent generations of British 6-inch rifled breechloading naval guns, designed by the...

February 1915. The Mark I–V had many relatively minor differences in the carriages and trails and Mk IV, Mk VI and QF Mk II 6-inch naval gun barrels were used...

The BL 4-inch Mark VIII naval gun was a British medium-velocity wire-wound naval gun introduced in 1908 as an anti-torpedo boat gun in smaller ships whose...

The BL 9.2-inch Mk IX and Mk X guns were British breech loading 9.2-inch (234 mm) guns of 46.7 calibre, in service from 1899 to the 1950s as naval and...

also used as a coast defence gun. This QF gun was introduced to provide a higher rate of fire than the BL 4 inch Mk VII. It first appeared in 1914 as...

The BL 12 inch naval gun Mk I was a British rifled breech-loading naval gun of the early 1880s intended for the largest warships such as battleships and...

The QF 4.7-inch Gun Mks I, II, III, and IV were a family of British quick-firing 4.724-inch (120 mm) naval and coast defence guns of the late 1880s and...

The BL 6-inch Mark XI naval gun was a British 50 calibres high-velocity naval gun which was mounted as primary armament on cruisers and secondary armament...

Elswick BL 16.25 inch naval gun was an early British superheavy rifled breech-loading naval gun, commonly known as the 110-ton gun or 111-ton gun. Elswick...

The BL 6-inch Mk XXII gun was a British high-velocity 6-inch 50-calibre wire-wound naval guns deployed on the Nelson-class battleships from the 1920s...