RML 64-pounder 58 cwt

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Ordnance RML 64 pounder 58 cwt gun (converted)
Cannon in Gibraltar.JPG
64 Pounder (58 cwt) RML gun on iron depression carriage, c1872. One of several preserved in Gibraltar
TypeCoast defence gun
Place of originUnited Kingdom
Service history
In service1870–1902
Used byBritish Army
British Colonies
Production history
DesignerLt Col William Dundas
ManufacturerRoyal Gun Factory
VariantsOne mark only
Mass6,496 pounds (2,947 kg)
Barrel length103.27 inches (2.623 m) (bore)[1]

Shell64 pounds (29.03 kg)
Calibre6.3-inch (160.0 mm)
CarriageGarrison carriage
Muzzle velocity1,230 feet per second (370 m/s)[2]
SightsCentre sighted

The RML 64-pounder 58 cwt guns (converted) were British rifled muzzle-loading guns converted from obsolete smoothbore 32-pounder 58 cwt guns.[note 1]


When Britain adopted rifled ordnance in the 1860s it still had large stocks of serviceable but now obsolete smoothbore guns. Gun barrels were expensive to manufacture, so the best and most recent models were selected for conversion to rifled guns, for use as second-line ordnance, using a technique designed by William Palliser. The Palliser conversion was based on what was accepted as a sound principle that the strongest material in the barrel construction should be innermost, and hence a new tube of stronger wrought iron was inserted in the old cast iron barrel, rather than attempting to reinforce the old barrel from the outside.[1]

This gun was based on the cast-iron barrel of the Dundas Pattern 32-pounder 58 cwt gun, which previously fired a 32-pound solid shot.[3] The gun was bored out to 10.5 inches and a new built-up wrought iron inner tube with inner diameter of 6.29 inches was inserted and fastened in place. The gun was then rifled with 3 grooves, with a uniform twist of 1 turn in 40 calibres (i.e. 1 turn in 252 inches), and proof fired. The proof firing also served to expand the new tube slightly and ensure a tight fit in the old iron tube.[1]


2nd Hampshire Artillery Volunteers with 64 Pounder (58 cwt) gun at drill, Southsea, c1895 (IWM Q41452)

This nature of gun did see Naval Service (NS) with the Naval Forces of the Colony of Victoria in Australia aboard the ex Ship-of-the-Line Nelson. To maintain maximum capability the gunners aboard the Nelson were drilled for both Smooth Bore and Rifled ammunition, and so the guns retained the original Millar Pattern sights as well as having one set of R.M.L. sights placed to the right of the centre line - otherwise the sighting arrangement normally used in British service was a single set of R.M.L. sights on the centre line. The mountings used on this vessel were Wood Naval Standing Carriages.

The gun mountings for coast defence in both British and colonial locations varied enormously. Carriages in both wood and iron varied in complexity – from a simple wooden garrison carriage, traversing carriages, right through to some guns mounted on Moncrieff Disappearing gun carriages.

They became obsolete for coast artillery use in 1902, whereupon most of them were scrapped and disposed of.

See also[edit]

Surviving examples[edit]


  1. ^ "58 cwt" refers to the gun's weight rounded up to differentiate it from other "64-pounder" guns : 1 cwt = 112 pounds.


  1. ^ a b c Treatise on Construction and Manufacture of Service Ordnance, 1879, pages 233-238, 292
  2. ^ 1,230 feet/second firing 64-pound projectile with charge of 8 pounds gunpowder. Treatise on Construction of Service Ordnance 1879, page 94
  3. ^ Blackmore, H L, (1976). The Armouries of the Tower of London: The Ordnance, (HMSO, London), p91
  4. ^ [1]


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