It was mounted on the following ships : Its 25-pound (11 kg) shell proved insufficiently powerful to make it much of an improvement on the 12-pounder.

From 1907 onwards it was succeeded in its class on new warships by the BL 4 inch gun Mk VIII, which fired a 31-pound (14 kg) shell.

[4] On 20 September 1914 the British cruiser HMS Pegasus was sunk by SMS Königsberg in Zanzibar harbour.

Her 8 QF 4-inch Mk III guns were recovered and used ashore in the East African campaign.

Two guns, and from 11 February 1916, three guns, were used by 10th Heavy Battery manned by the Royal Marines, mounted on improvised field carriages and towed by Packard lorries, supported by six REO lorries carrying ammunition.