# RML 7-pounder mountain gun

The Ordnance RML 7-pounder Mk IV "Steel Gun" was a British rifled muzzle-loading mountain gun. 7-pounder referred to the approximate weight of the shell it fired.

## History

Development began in 1864 to replace the RBL 6-pounder 2.5-inch (64 mm) gun of 3 long hundredweight (340 lb; 150 kg), which had proved too heavy for a mountain gun. Several Mks of 7-pounder RML of 2 long hundredweight (220 lb; 100 kg) 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It was superseded by the RML 2.5-inch Mountain Gun from 1879.

## Combat use

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.

### Anglo-Zulu War 1879

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. Two of these guns deployed as field guns of the N/5th Brigade, Royal Field Artillery were lost in the disastrous Battle of Isandlwana.

### Second Anglo-Afghan War

An RML 7-pounder Mountain Gun appears to be present in a photograph by John Burke (photographer) from the Second Anglo-Afghan War (November 1878 – September 1880). The war began when Great Britain, fearful of what it saw as growing Russian influence in Afghanistan, invaded the country from British India. The first phase of the war ended in May 1879 with the Treaty of Gandamak, which permitted the Afghans to maintain internal sovereignty but forced them to cede control over their foreign policy to the British. Fighting resumed in September 1879, after an anti-British uprising in Kabul, and finally concluded in September 1880 with the decisive Battle of Kandahar.

### First Boer War 1880–1881

Britain deployed 4 guns mounted on standard small mountain carriages during the war.

### War of the Golden Stool 1900

The West African Frontier Force fielded a number of guns in the War of the Golden Stool, their use being fairly heavily referenced by Willcocks, Armitage and Montanaro in their books on the campaign. Bartlett also references the Central African Regiment having a battery of 7-pounder guns attached to A Company in 1898, with the Central African Regiment taking part in the war.

### Second Boer War 1899–1902

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.

### Anglo-Aro War

Column No. 4 of The British assembled Aro Field Force deployed one 7-pounder gun during the battles in and around Arochukwu.