The QF 5.25-inch Mark I gun was the heaviest dual-purpose gun used by the Royal Navy during the Second World War. Although considered less than completely successful, it saw extensive service. 267 guns were built.
5.25-inch turret on HMS Sirius. The empty cartridge cases from firing in support of the Allied invasion of Normandy, June 1944
QF 5.25-inch Mark I turret on HMS King George V
Inside a 5.25-inch gun turret on HMS King George V in 1943.
Twin naval anti-aircraft mounting at Primrose Hill, London, August 1943
A dual-purpose gun is a naval artillery mounting designed to engage both surface and air targets.
The Mark 37 Modification 6 5-inch dual-purpose gun on display at the National Museum of the Pacific War. The gun had a range of over 6 miles and could fire 22 rounds a minute.