BRITISH 4 INCH QF MARK IV NAVAL GUN
This gun from the destroyer HMS Lance fired the first British gun-round of the First World War.
On 5th August 1914 HMS Lance, HMS Landrail and HMS Amphion of the 1st Destroyer Flotilla were on patrol in the North Sea. Off the Dutch coast they encountered the German minelayer, Konigin Luise, and by sinking her made her the first naval casualty of the war. HMS Lance fired the first round in the action.
The 4-inch Quick Firing Mark IV was semi-automatic with the recoil opening the breech and ejecting the cartridge. Insertion of a new cartridge closed the breech and the gun was then ready to fire again. Thus a rate of fire of 15-20 rounds a minute could be obtained by a trained gun crew.
CALIBRE: 4 inches(10,1 cm)
RANGE: 10,200 yards(9,326 m)
AMMUNITION: 31 lb(14 kg) high explosive
HMS Lance is launched, 25 February 1914