Intended for the cruisers Mersey and Severn with three guns and one mounting included in the 1884-1885 estimates, but later cancelled. Also known as the "7-inch 10 ton gun."
An experimental Army gun of the same or similar design was built and delivered in 1887-1888.
Constructed of A tube, breech piece taking the screw block and hooped to the muzzle. The outer layer consisted of a long hoop, trunnion hoop and another hoop.
With 160 lbs. (72.6 kg) shell and 100 lbs. (45.4 kg) of pebble charge the muzzle velocity was 2,250 fps (686 mps).
This gun was later relined to a long experimental 4.7" (12 cm) QF type.