Britain
Early 6" (15.2 cm) Breech Loaders


6"/26 (15.2 cm) BL Mark I
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6"/26 (15.2 cm) BL Mark II
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6"/26 (15.2 cm) BL Mark III
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6"/26 (15.2 cm) BL Mark IV
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6"/30 (15.2 cm) BL Mark V
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6"/26 (15.2 cm) BL Mark VI

Updated 30 November 2015


This page is a collection of early British 6" (15.2 cm) breech loader bag guns from the late 1800s.  These guns shared common characteristics including weak design and few of them survived in active service after 1900.  Rate of fire for all of these guns was about four rounds per minute.

Many of these weapons were converted to QF guns in the 1890s.

As detailed information for these guns is limited, rather than creating a page for each one, I have decided to combine them into a single page.

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6"/26 (15.2 cm) BL Mark I
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This was Elswick Pattern 'D' and 19 were purchased by the Royal Navy in 1879 - 1880.  Used on corvettes Constance, Cordelia and on the following gunboats for a limited time:  Curlew, Landrail, Blazer, Bulldog and Kite.  Construction was steel 'A' tube into which the breech mechanism screwed.  The 'A' tube had a layer of three wrought iron coils and a second layer of two wrought iron coils with a forged wrought iron trunnion ring between them.  These guns were too weakly made, so part of the 'A' tube and the foremost inner coil was removed and then the guns were chase hooped.  This consisted of two shrunk-on steel hoops extending to the muzzle and another steel hoop being added ad a new outer layer.  Elswick cup obturation was used.  Unlike all other British 6" (15.2 cm) guns, this gun fired an 80 lbs. (36.3 kg) shell.  Bore length was 26.3 calibers as built and 25.53 calibers as chase hooped.  Mountings were Armstrong Broadside (AB Mark I) allowing an elevation range of -8 to +13 degrees.

A charge of 34 lbs. (15.4 kg) SP gave a muzzle velocity of 1,880 fps (573 mps) and range was 7,025 yards (6,420 m) at +13 degrees.

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6"/26 (15.2 cm) BL Mark II
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A Fraser design from the Royal Gun Factory at Woolwich.  Gun lists show usage on Agamemmon, Ajax, Hotspur, Raleigh, Boadicea, Bacchante, Euryalus, Volage, Active, Canada, Cordelia, Emerald, Dolphin, Pelican, Wanderer, Wild Swan, Spinx, Heroine and Satellite, although it is not certain that all of these ships actually received these guns.  Constructed of a thick steel barrel into which the breech mechanism screwed.  A coiled wrought iron jacket was welded to the forged trunnion ring.  Cup obturation was used.  For some reason, only 31 guns were chase hooped, which involved shortening the barrel by 12 inches (30.5 cm) and shrinking on five steel hoops from jacket to muzzle.  A total of 143 guns were manufactured.  Mark IIP indicated a percussion lock and Mark IIPA had special breech fittings to suit the corvettes Heroine and Satellite.  Bore length was 26.0 calibers as built and 24.0 calibers as chase hooped.

Most mountings were AB Mark I and VB Mark I which allowed a range of elevation of -6 to +16 degrees.  Some guns had VCP Mark I or Mark I* which allowed -7 to +20 degrees elevation.  The battleships Agamemmon and Ajax had Albini CP mountings with the guns recoiling in an arc of a circle and had an elevation range of -10 to +15 degrees.

These guns were weakly made and several ships suffered damage, including one on the corvette Active which had five feet (1.5 m) of the chase blown off.  After one of these gun burst on Cordelia in June 1891, killing six crewman and wounding thirteen, all of these guns were deactivated and then used only for drill purposes.  To increase their usefulness in this role, 43 were converted to QF drill guns.

A charge of 36 lbs. (16.3 kg) EXE gave a muzzle velocity of 1,672 fps (510 mps) and range was 7,590 yards (6,940 m) at +15 degrees.

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6"/26 (15.2 cm) BL Mark III
6"/26 (15.2 cm) BL Mark IV
6"/26 (15.2 cm) BL Mark VI
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These guns were interchangeable and mixed batteries were not uncommon, although the Mark III was 0.47 calibers shorter than the other Marks.  All guns were of steel construction.  These guns were used on battleships from the Colossus class to Victoria and Sans Pareil, large cruisers of the Imperieuse, Aurora and Blake classes, smaller cruisers of the Calliope, Calypso, Leander, Archer, Mersey, Medea classes and all Apollo class except for Aeolus, Brilliant and Iphigenia.  They also replaced the Mark II guns in all ships except Bacchante, Euryalus, Heroine and Wanderer.  They were used for a brief time in Achilles, Bellerophon, Black Prince, Northumberland, Rupert, Champion, Cleopatra, Curacoa, Tourmaline, Curlew, Landrail and the school gunboats Blazer, Bulldog, Kite and Plucky.

The Mark III had an 'A' tube with a breech piece taking the breech block and a hoop.  These were linked by a two part key ring.  Over these were five hoops including the trunnion hoop.  Again, these guns prooved to be weakly constructed and so they were chase hooped with the first layer comprising the breech piece and six hoops to the muzzle.  The second layer consisted of five hoops and a new trunnion ring interlocking with the breech piece and the hoop next to it.  The trunnions were moved 4.4 inches (11 cm) closer to the muzzle in order to restore balance.  This rebalancing meant that this gun did not need to be shortened as in previous chase hoopings and so retained its full length.  Actual bore length was 25.53 calibers.

The Mark IV was constructed of 'A' tube and breech piece, which held the breech block, 'B' tube, three hoops to the muzzle with a one piece jacket which held the trunnions and interlocked with the 'B' tube.  There was also one hoop over this.  Actual bore length was 26.0 calibers.

Mark VI was the same as the Mark IV except that a second 'B' tube replaced the three hoops to the muzzle.  Actual bore length was 26.0 calibers.

Most mountings were AB Mark I and VB Mark I with some Albini CP mountings.  The latter were replaced about 1892 with VB Mark II and III which allowed an elevation range of -7 to +16.  There were also BCP Mark III mountings with an elevation range of -7 to +20 degrees.  The AB mountings were restricted to 3/4 charges unless they had been specially strengthened.

In service with the Royal Navy were 112 Mark III, 326 Mark IV and 113 Mark VI.  There were also 65 Mark IV and about 88 Mark BVI land service guns used for coast defense, some in mobile siege gun mountings used particularly in India.

By July 1888 forty guns were still not chase hooped and 31 of these were on the battleships Rupert and Bellerophon, the cruisers Leander and Phaeton, corvette Tourmaline and gunboat Bulldog.  These guns were restricted to 3/4 charges and were soon replaced except for those on Bellerophon.

CPC and HE common shells were used, both of 100 lbs. (45.3 kg).  HE Common had a burster of 9.25 lbs. (4.2 kg) and the projectile was 26.5 in (67.3 cm) long.

A charge of 48 lbs. (21.8 kg) EXE or PBl gave a muzzle velocity of 1,960 fps (597 mps) and range was 8,830 yards (8,070 m) at +15 degrees.

Images at Australian War Memorial

6" (15.2 cm) gun on a VB Mounting

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6"/30 (15.2 cm) BL Mark V
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These were ten guns made by Elswick to their pattern K1 and were used in the defenses of Hong Kong.  Actual bore length was 30.58 calibers and they had a muzzle velocity of 1,920 fps (585 mps) with 100 lbs. (45.3 kg) shells.  A number of similar or identical guns were purchased for the coastal defenses of New Zealand, Australia and also mounted in the colonial gunboats Gayundah, Paluma, Protector and Albert.  A few Australian coast defense guns were converted to QFC and then had a muzzle velocity of 2,081 fps (634 mps).
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Data from
"British Naval Guns 1880-1945 No 10" article by John Campbell in "Warship Volume VII"
"British Battleships:  1860 - 1950" by Oscar Parkes
Page History

20 October 2008 - Benchmark
28 August 2010 - Added rate of fire
11 February 2012 - Updated to latest template
30 November 2015 - Updated links to Australian War Memorial