These were 6"/26 (15.2 cm) BL guns converted to take the same cartridge case and charges as the 6"/40 (15.2 cm) QF guns. A total of 73 Mark III, 247 Mark IV and 81 Mark VI were altered and there were eight different Mark numbers assigned, although they were always referred to only as 6" (15.2 cm) QFC guns in gun lists.

These QFC guns were mounted from 1895 on the battleships of the Colossus class to the Sans Pareil and in cruisers of the Imperieuse, Aurora, Leander, Archer, Mersey and Medea classes. A few survived to serve on DAMS during World War I as pictured below and two were mounted at Ft. Bedford, Ascension Island.

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. In the designations shown below, the first mark number before the "/" represents the original BL designation and the number following the "/" represents the modification made to that particular BL Mark.

6"/26 (15.2 cm) Marks I/IV and I/VI

Elswick conversion design. Modified chamber and used a short bore liner to the start of original liner, or further if the rifling was worn. The liner engaged screw threads cut on the breech piece and jacket and a breech ring was shrunk on over the rear of the jacket.

6"/26 (15.2 cm) Marks II/III, II/IV and II/VI

Woolwich conversion design with the liner and breech bush being two separate components. The liner was secured by a screw collar at the rear end of the 'A' tube and extended to the start of the rifling, half way up the bore or to the muzzle, depending upon the wear. Breech ring added.

6"/26 (15.2 cm) Marks III/IV and III/VI

Elswick conversion design. Like the Mark II, but different breech bush, pinned through the jacket, and a shorter breech ring.

6"/26 (15.2 cm) Marks III/III

Elswick conversion design. Like the Mark II but with differences in the securing of the breech ring and liner.

Other Details

Gun weight was 5.107 tons (5.3 mt) for most conversions.

Mountings were all of the Vavasseur type and comprised VB Mark IC (-6 / +12 degrees), VB Mark IIC and Mark IIIC (-7 / +16 degrees), VCP Mark IC (-7 / +16.5 degrees) and VCP Mark IIC (-7 / +20 degrees).

A charge of 29.75 lbs. (13.5 kg) EXE gave a muzzle velocity of 1,913 fps (583 mps) and a range of 8,625 yards (7,890 m) at an elevation of 15 degrees.

A charge of 13.25 lbs. (6.0 kg) Cord 30 gave a muzzle velocity of 2,061 fps (628 mps) and a range of 9,275 yards (8,480 m) at an elevation of 15 degrees.

The Royal Sovereign class carried 200 rounds per gun upon completion. During design, it had been planned to carry about 150 rounds per gun, which would have been made up of 10 AP, 38 Palliser, 128 Common and 24 Shrapnel.

Armor Penetration

100 lbs. (45.3 kg) CPC
Range Wrought Iron Vertical Armor
0 yards (0 m) 12.5 in (318 mm)
200 yards (180 m) 8.0 in (203 mm)

Data from "Warship Volume IV" article by R.A. Burt.

Range Wrought Iron Vertical Armor
1,000 yards (910 m) 10.5 in (267 mm)

Data from "British Battleships: 1860 - 1950" by Oscar Parkes.


Data from:

  • "The Magnificent 7: The Royal Sovereign Class of 1889" article by R.A. Burt in "Warship Volume IV"
  • "British Naval Guns 1880-1945 No 10" article by John Campbell in "Warship Volume VII"
  • "British Battleships: 1860 - 1950" by Oscar Parkes


Page History

27 March 2007
29 August 2011
Corrected typographical error
11 February 2012
Updated to latest template