RML 64 pounder 64 cwt gun

The RML 64 pounder 64 cwt gun was a Rifled, Muzzle Loading (RML) naval, field or fortification artillery gun manufactured in England in the 19th century, which fired a projectile weighing approximately 64 lb. "64 cwt" refers to the gun's weight rounded up to differentiate it from other "64-pounder" guns : 1 hundredweight (cwt) = 112 pounds.

Description
The calibre of 6.3 inches was chosen to enable it to fire remaining stocks of spherical shells originally made for the obsolete 32 pounder guns if necessary.

Mark I (adopted in 1864) and Mark II (adopted 1866) guns, and Mark III guns made from 1867 - April 1871 had wrought-iron inner "A" tubes surrounded by wrought-iron coils.

Mark III guns made after April 1871 were built with toughened mild steel "A" tubes, and earlier Mark III guns were re-tubed with steel and were classified as a siege gun in land service. Remaining guns with iron tubes were used for sea service.

Rifling of all guns consisted of 3 grooves, with a uniform twist of 1 turn in 40 calibres (i.e. 1 turn in 252 inches).

Ammunition
The gun's standard shell was "common shell", for firing on troops in cover, ships and buildings, weighed 57.4 lb when empty with a bursting charge of 7.1 lb. Shrapnel shells could also be fired; a 66.6 lb shell with a 9 oz bursting charge propelling 234 metal balls.

Surviving examples

 * Mk I, Mk II and Mk III guns at Fort George, near Inverness, Scotland, UK
 * At Nothe Fort, Weymouth, UK
 * A Mk III gun at Fort Brockhurst, Gosport, UK
 * On board HMS Gannet, Chatham Dockyard, UK
 * At Pendennis Castle, Cornwall, UK
 * At Fort Glanville, Adelaide, South Australia
 * Mk III gun no. 739 of 1878 at Townsville, Queensland, Australia
 * Two guns at Fort Lytton, Brisbane, Australia
 * Lei Yue Mun Fort's Central Battery, Hong Kong
 * 6 guns at Fort Siloso, Singapore. See also Mk III gun No. 767 of 1874
 * RML 64-pr 64 cwt Mk 3 at Albert Park, Auckland, Auckland, New Zealand