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 inches (63.5 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 (86.2 kg) and 150 lb (68 kg) but were not considered powerful enough.

Mk IV of 200 lb (90.7 kg) with a longer bore was settled on for production in 1873.

It was superseded by the RML 2.5 inch Mountain Gun

RML 2.5 inch Mountain Gun

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.-History:...

 from 1879.
It could be assembled and a round loaded in 20 seconds.