RML 64 pounder 64 cwt gun

RML 64 pounder 64 cwt gun
Fortification mounted MK III gun firing at Fort Glanville Conservation Park, South Australia
Type	Naval gun Fortification gun
Place of origin	United Kingdom
Service history
In service	1865 - 190?
Used by	British Empire
Production history
Designer	Woolwich Arsenal
Designed	1864
Manufacturer	Woolwich Arsenal Elswick Ordnance Company
Variants	Mk I, II, III
Specifications
Weight	64-long-hundredweight (3,300 kg)
Length	9 ft 10 inches
Barrel length	97.5 inches bore
Shell	64 pounds (29 kg)
Calibre	6.3 inches (160 mm)
Action	RML
Breech	none – muzzle-loading
Muzzle velocity	wrought-iron tube : 1,252 feet per second (382 m/s) Mk III steel tube : 1,390 feet per second (420 m/s)
Effective firing range	5,000 yards (4,600 m)

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 pounds (29 kg). "64 cwt" refers to the gun's weight rounded up to differentiate it from other "64-pounder" guns.

The calibre of 6.3 inches was chosen to enable it to fire remaining stocks of spherical shells originally made for the obsolete 32 pounder guns if necessary.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

The gun's standard shell was "common shell", for firing on troops in cover, ships and buildings, weighed 57.4 pounds (26.0 kg) when empty with a bursting charge of 7.1 pounds (3.2 kg). Shrapnel shells could also be fired; a 66.6 pounds (30.2 kg) shell with a 9-ounce (260 g) bursting charge propelling 234 metal balls.