Second gun born from a British Army technical specification inspired from Rheinmetall guns bought in 1900, the 18 pounder gun, planned for a Field Artillery usage was nearly abandonned before 1914, and replaced by the Horse Artillery more manoeuvrable 13 pounder, from the same generation.

Only the inpired intervention from the Prime Minister Balfour saved its deployment in the Army from 1906.

The first fights of 1914 proved this decision was wise, the 'QF 18-pounder gun' being more efficient (particularly in power - with its heavier shell), in both its Mk I and Mk II versions. Equipped with a screw breech mechanism, its main weaknesses were the relatively low range induced by its tubular trail, that limited the elevation angle, and the fragile hydro-mechanic recuperating system.

The range issue was only solved by the substitution of the pole trail with a polygonal one on the Mk IV version (that only participated in the late battles in small quantities).The recuperator weakness was fixed during the war by the addition of a oil reservoir box at the front end of the classical break, or by the substitution of the whole system with hydro-pneumatic system (that gave to the break front end a characteristic torpedo-like shape).

1135 such guns were produced before WW1, and 8393 other ones during the war. They were distributed to all the British Empire armies (Canada, South Africa, Australia and New Zealand). USA manufactured anoyher 851 guns for the United Kingdom before 1917, then modified the design so that this gun could fire French 75mm shells. These guns were named 'Gun, 75mm, M1917 (British)' and used by the American Expeditionary Forces (AEF) in Europe.

Main characteristics :

• Weight in firing position : 1285 kg
• Calibre : 83.8 mm (3.3 in.)
• Tube length : 29.4 calibres
• Poids du projectile : 8.4 kg
• Initial velocity : 492 m/s
• Maximum range : 8700 / 10150 m
• Elevation range : -5 / +16 degrees
• Direction range : 8 degrees total range