RML 2.5 inch Mountain Gun
Encyclopedia
The Ordnance RML 2.5 inch mountain gun was a British rifled muzzle-loading mountain gun
of the late 19th century designed to be broken down into four loads for carrying by man or mule. It was primarily used by the Indian Army
.
It was intended as a more powerful successor to the RML 7 pounder Mountain Gun
. Some writers incorrectly refer to the 2.5 inch gun as a "7 pounder" because it also fired a shell of approximately 7 pounds, but its official nomenclature was 2.5 inch RML.
In 1877 Colonel le Mesurier of the Royal Artillery proposed a gun in 2 parts which would be screwed together. The Elswick Ordnance Company made 12 Mk I guns based on his design and they were trialled in Afghanistan in 1879. Trials were successful and Mk II with some internal differences made by the Royal Gun Factory
entered service.
The gun was a rifled muzzle-loader. Gun and carriage were designed to be broken down into their basic parts so they could be transported by pack animals (4 mules) or men. The barrel and breech were carried separately, and screwed together for action, hence the name "screw gun".
The gun was used in the Second Boer War
(1899–1902) on its standard mountain gun carriage, and also with the Natal Field Battery at Elandslaagte
and Diamond Fields Artillery at Kimberley
on field carriages which had larger wheels and gave greater mobility.
A major defect in the war was that the gun's cartridges still used gunpowder
as a propellant, despite the fact that smokeless cordite
had been introduced in 1892. The gunpowder generated a white cloud on firing, and as the gun could only be aimed using direct line of sight, this made the gunners easy targets for Boer marksmen as the gun lacked a shield.
It proved to be ineffectual and outclassed by Boer ordnance and was replaced by the BL 10 pounder Mountain Gun
from 1901.
. Writers who refer to "7 pounders" in WWI are in fact referring to this 2.5 inches (63.5 mm) gun.
Mountain gun
Mountain guns are artillery pieces designed for use in mountain warfare and areas where usual wheeled transport is not possible. They are similar to infantry support guns, and are generally capable of being broken down into smaller loads .Due to their ability to be broken down into smaller...
of the late 19th century designed to be broken down into four loads for carrying by man or mule. It was primarily used by the Indian Army
British Indian Army
The British Indian Army, officially simply the Indian Army, was the principal army of the British Raj in India before the partition of India in 1947...
.
History
RML 7 pounder Mountain Gun
The Ordnance RML 7 pounder Mk IV "Steel Gun" was a rifled muzzle-loading mountain gun primarily used by the Indian Army. 7 pounder referred to the approximate weight of the shell it fired.-History:...
. Some writers incorrectly refer to the 2.5 inch gun as a "7 pounder" because it also fired a shell of approximately 7 pounds, but its official nomenclature was 2.5 inch RML.
In 1877 Colonel le Mesurier of the Royal Artillery proposed a gun in 2 parts which would be screwed together. The Elswick Ordnance Company made 12 Mk I guns based on his design and they were trialled in Afghanistan in 1879. Trials were successful and Mk II with some internal differences made by the Royal Gun Factory
Royal Arsenal
The Royal Arsenal, Woolwich, originally known as the Woolwich Warren, carried out armaments manufacture, ammunition proofing and explosives research for the British armed forces. It was sited on the south bank of the River Thames in Woolwich in south-east London, England.-Early history:The Warren...
entered service.
The gun was a rifled muzzle-loader. Gun and carriage were designed to be broken down into their basic parts so they could be transported by pack animals (4 mules) or men. The barrel and breech were carried separately, and screwed together for action, hence the name "screw gun".
Second Boer War
Second Boer War
The Second Boer War was fought from 11 October 1899 until 31 May 1902 between the British Empire and the Afrikaans-speaking Dutch settlers of two independent Boer republics, the South African Republic and the Orange Free State...
(1899–1902) on its standard mountain gun carriage, and also with the Natal Field Battery at Elandslaagte
Battle of Elandslaagte
The Battle of Elandslaagte was a battle of the Second Boer War, and one of the few clear-cut tactical victories won by the British during that conflict...
and Diamond Fields Artillery at Kimberley
Siege of Kimberley
The Siege of Kimberley took place during the Second Boer War at Kimberley, Cape Colony , when Boer forces from the Orange Free State and the Transvaal besieged the diamond mining town. The Boers moved quickly to try to capture the British enclave when war broke out between the British and the two...
on field carriages which had larger wheels and gave greater mobility.
A major defect in the war was that the gun's cartridges still used gunpowder
Gunpowder
Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...
as a propellant, despite the fact that smokeless cordite
Cordite
Cordite is a family of smokeless propellants developed and produced in the United Kingdom from 1889 to replace gunpowder as a military propellant. Like gunpowder, cordite is classified as a low explosive because of its slow burning rates and consequently low brisance...
had been introduced in 1892. The gunpowder generated a white cloud on firing, and as the gun could only be aimed using direct line of sight, this made the gunners easy targets for Boer marksmen as the gun lacked a shield.
It proved to be ineffectual and outclassed by Boer ordnance and was replaced by the BL 10 pounder Mountain Gun
BL 10 pounder Mountain Gun
The Ordnance BL 10 pounder mountain gun was developed as a BL successor to the RML 2.5 inch screw gun which was outclassed in the Second Boer War.-History:...
from 1901.
World War I
Either 4 or 6 guns (sources appear imprecise) were returned to service from Southern African garrisons in 1916 and were employed by the Nyasaland-Rhodesian Field Force in the campaign in German East AfricaEast African Campaign (World War I)
The East African Campaign was a series of battles and guerrilla actions which started in German East Africa and ultimately affected portions of Mozambique, Northern Rhodesia, British East Africa, Uganda, and the Belgian Congo. The campaign was effectively ended in November 1917...
. Writers who refer to "7 pounders" in WWI are in fact referring to this 2.5 inches (63.5 mm) gun.
Surviving examples
- Restored gun is displayed at Firepower, the Royal Artillery Museum. Woolwich London
- Two 2.5 inches (63.5 mm) RMLs on Field carriages and one on a Mountain carriage, at Fort Klapperkop Military Museum, Pretoria, South Africa.