RML 64 pounder 58 cwt

Ordnance RML 64 pounder 58 cwt gun (converted)

64 Pounder (58 cwt) RML gun on iron depression carriage, c1872. One of several preserved in Gibraltar
Type Coast defence gun
Place of origin United Kingdom
Service history
In service 1870 - 1902
Used by British Army
British Colonies
Production history
Designer Lt Col William Dundas
Designed 1847
Manufacturer Royal Gun Factory
Variants One mark only
Weight 6,496 pounds (2,947 kg)
Barrel length 103.27 inches (2.623 m) (bore)[1]

Shell 64 pounds (29.03 kg)
Calibre 6.3-inch (160.0 mm)
Carriage Garrison carriage
Muzzle velocity 1,230 feet per second (370 m/s)[2]
Sights Centre 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 32-pounder 58 cwt gun, which previously fired a 32 pound solid shot. 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)

Unlike the 71 cwt converted gun, this nature of gun was issued for Land Service (LS) only. [3]

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

Surviving examples


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


  1. 1 2 3 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. Treatise on Construction and Manufacture of Service Ordnance (3rd ed), HMSO, 1886, page 219


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