RML 7 pounder Mountain Gun
|Ordnance RML 7 pounder Mk IV Mountain Gun|
No. 4 (Hazara) Mountain Battery with RML 7 pounder circa. 1895
|Place of origin||United Kingdom|
|In service||1873 - 19?|
|Used by|| British Empire
First Boer War
Second Boer War
|Weight||200 pounds (90.72 kg) barrel|
|Barrel length||3 feet (914 mm)|
|Shell||7lb 11 oz (Shrapnel)
7lb 4oz (Common)
12lb 4oz (Double)
|Calibre||3 inches (76.2 mm)|
|Muzzle velocity||968 ft/s (295 m/s)|
|Maximum firing range||3,000 yd (2,700 m)|
Development began in 1864 to replace the RBL 6 pounder 2.5-inch (64 mm) gun of 3cwt, which had proved too heavy for a mountain gun. Several Mks of 7 pounder RML of 2 cwt were tried in 1865 by boring out and rifling old SBML bronze guns, but were still too heavy.
Several Mks of new steel barrels (the first British all-steel gun, hence the name "Steel Gun") were then produced of 190 lb (86 kg) and 150 lb (68 kg) but were not considered powerful enough.
Mk IV of 200 lb (91 kg) with a longer bore was settled on for production in 1873.
It was superseded by the RML 2.5 inch Mountain Gun from 1879.
It could be assembled and a round loaded in 20 seconds. Its Common shell was considered ineffective. To give it a high angle capability, a Double shell was produced of increased length and containing a larger bursting charge. This was fired with a reduced charge, but the low muzzle velocity did not always arm the fuze, or prevent the over-long projectile from somersaulting. Shell rotation was effected by studs on the body of the shell. Elevation was by quoin or wedge and by screw. 
Britain deployed several guns mounted on Colonial (or "Kaffraria") carriages : light field gun type carriages with larger wider-spaced wheels suited for being horse-drawn across long grass.
Britain deployed 4 guns mounted on standard small mountain carriages during the war.
The gun was employed mounted on armoured trains and used by local militia forces early in the war.
It was also employed mounted on normal field carriages with larger wheels which increased mobility in the long grass and allowed it to be towed by horses.
Column No. 4 of The British assembled Aro Field Force deployed one 7 pounder gun during the battles in and around Arochukwu.
Today, several examples of the guns still exist around the world :
- at the Regional Military Training Center in Darulaman Garrison, Kabul. The garrison is near the palaces, and south of the Bala Hissar where the British had their headquarters during the Anglo-Afghan wars.
- A gun at Royal Armouries, Fort Nelson, Hampshire, UK
- Royal Artillery Museum, London
- South African National Museum of Military History, Johannesburg, South Africa
Notes and references
- Hall, December 1972
- Hall, June 1971
- Major Darrell D Hall, "Guns in South Africa 1899-1902" in The South African Military History Society Military History Journal - Vol 2 No 1, June 1971
- Major Darrell D. Hall, "Field Artillery of the British Army 1860-1960. Part I, 1860 - 1900" in The South African Military History Society. Military History Journal - Vol 2 No 4, December 1972 (web page is incorrectly titled 1900-1914)
- W. L. Ruffell, The Gun - Rifled Ordnance: Mountain Artillery. RML 7 pounder
- Major D.D. Hall, The South African Military History Society Military History Journal Vol 4 No 4, December 1978. "ARTILLERY IN THE ZULU WAR - 1879"
- Major D.D. Hall, The South African Military History Society Military History Journal - Vol 5 No 2, December 1980. "The Artillery of the First Anglo-Boer War 1880 - 1881"
- MAJOR G. TYLDEN, ED, The South African Military History Society Military History Journal - Vol 1 No 2, June 1968. Further Notes on Early Rhodesian Military Units and Early Rhodesia's Weapons
|Wikimedia Commons has media related to RML 7 pounder Mountain Gun.|
- Diagram of carriage, 7-pounder gun of 200 Lbs Mk I and Text at Victorian Forts and Artillery website.