1-pounder

QF 1 pdr Mark I & II ("pom-pom")
Mk II gun dated 1903, on anti-aircraft mounting, at the Imperial War Museum, London.
Type
Place of origin	United Kingdom of Great Britain and Ireland
Service history
In service	1890s–1918
Used by	South African Republic British Empire German Empire Belgium United States
Wars	Spanish–American War Second Boer War World War I
Production history
Designer	Hiram Maxim
Designed	Late 1880s
Manufacturer	Maxim-Nordenfelt Vickers, Sons & Maxim DWM
Variants	Mk I, Mk II
Specifications
Weight	410 pounds (186.0 kg) (gun & breech)
Length	6 ft 1 in (1.85 m) (total)
Barrel length	3 ft 7 in (1.09 m) (bore)
Shell	37 x 94R. 1 lb (0.45 kg) Common Shell
Calibre	37-millimetre (1.457 in)
Barrels	1
Action	automatic, recoil
Rate of fire	~300 rpm (cyclic)
Muzzle velocity	1,800 ft/s (550 m/s)
Maximum firing range	4,500 yards (4,110 m) (Mk I+ on field carriage)
Filling weight	270 grains (17 g) black powder

The QF 1 pounder, universally known as the pom-pom due to the sound of its discharge, was a 37 mm British , the first of its type in the world. It was used by several countries initially as an infantry gun and later as a light anti-aircraft gun.

Hiram Maxim originally designed the Pom-Pom in the late 1880s as an enlarged version of the Maxim machine gun. Its longer range necessitated exploding projectiles to judge range, which in turn dictated a shell weight of at least 400 grams (0.88 lb), as that was the lightest exploding shell allowed under the St. Petersburg Declaration of 1868 and reaffirmed in the Hague Convention of 1899.

Early versions were sold under the Maxim-Nordenfelt label, whereas versions in British service (i.e. from 1900) were labelled Vickers, Sons and Maxim (VSM) as Vickers had bought out Maxim-Nordenfelt in 1897. They are all effectively the same gun.

The Belgian Army used the gun on a high-angle field carriage mounting.

A version was produced in Germany for both Navy and Army.

In World War I, it was used in Europe as an anti-aircraft gun as the Maxim Flak M14. Four guns were used mounted on field carriages in the German campaign in South West Africa in 1915, against South African forces.

The British government initially rejected the gun but other countries bought it, including the South African Republic (Transvaal) government. In the Second Boer War, the British found themselves being fired on with success by the Boers with their 37 mm Maxim-Nordenfelt versions with ammunition made in Germany.

In response, Vickers-Maxim of Britain shipped either 57 or 50 guns out to the British Army in South Africa, with the first three arriving in time for the Battle of Paardeberg of February 1900. These early Mk I versions were mounted on typical field gun type carriages.