RML 7 pounder Mountain Gun

Ordnance RML 7 pounder Mk IV Mountain Gun
No. 4 (Hazara) Mountain Battery with RML 7 pounder circa. 1895
Type	Mountain gun
Place of origin	United Kingdom
Service history
In service	1873 - 19?
Used by	British Empire  India
Wars	Anglo-Zulu War First Boer War Second Boer War Anglo-Aro War
Specifications
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)
Traverse	nil
Muzzle velocity	968 ft/s (295 m/s)
Maximum firing range	3,000 yd (2,700 m)

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.

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It was superseded by the RML 2.5 inch Mountain Gun from 1879.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.

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.