Introduced to the Royal Navy in March of 1915 as a large-caliber AA MG. Generally similar to the later 2-pdr Mark VIII including using the same water-cooled barrel, but the automatic mechanism was lighter and less robust. First models used a 25-round fabric belts, the later Mark II*C used a 14-round steel-link belt. Used only in single mountings. Britain produced a total of 795 guns of which 577 were still available in 1939.

The original Mark II design was prone to faults and the later Mark II* was a modified version which improved reliability. Stoppages and jams were still frequent in these models, as the rounds slipped out of their holders and the fabric belts often stretched and tore.

Actual bore length was 39.37 calibers.

Some fifty of these guns were sold to the Italian Navy. They were then manufactured under license by Terni (Italy) until the early 1930s. The Terni version used a 50 round ammunition box.

Russia ordered a number of these guns from Vickers during World War I and by 1916 forty of them were on hand in the Russian Navy (20 each in the Baltic and Black Sea fleets). In 1916 the Russian Navy ordered sixty additional guns from the Obukhov factory with at least twelve of them being delivered by 1917. All of these weapons used 25 round belts.

There was also an earlier Mark I version, but I lack details as to what were the differences between it and the Mark II.

The data that follows is for the British version except where otherwise noted.

Gun Characteristics

Designation British: Vickers 2-pdr QF Mark II
Italian: 40 mm/39 Vickers-Terni 1915/1917
Russian: 40 mm/39 Vickers Automatic Model 1914
Ship Class Used On Many
Date Of Design about 1914
Date In Service British: 1915
Italian: about 1917
Russia: 1915
Gun Weight British and Italian: 550 lbs. (249 kg) including cooling water
Russian: 504.9 lbs. (229 kg) (probably does not include water)
Gun Length oa 96.0 in (2.438 m)
Bore Length 62.0 in (1.575 m)
Rifling Length 54.84 in (1.293 m)
Grooves (12) 0.0141 in deep x 0.322 (0.358 x 8.18 mm)
Lands 0.894 in (2.271 mm)
Twist Uniform RH 1 in 30
Chamber Volume 9.98 in3 (0.165 dm3)
Rate Of Fire 200 rounds per minute cyclical
about 50 - 75 rounds per minute practical


Type Fixed
Weight of Complete Round HE: 2.95 lbs. (1.34 kg)
Projectile Types and Weights
(see Note)
HE: 2.0 lbs. (0.9 kg)
Bursting Charge 0.21 lbs. (0.1 kg)
Projectile Length N/A
Complete round: 11.995 in (30.47 cm)
Propellant Charge 0.243 lbs. (0.11 kg) HSCT/K 134-055
Muzzle Velocity British: 1,920 fps (585 mps)
Italian: 2,000 fps (610 mps)
Russian: 1,972 fps (601 mps)
Working Pressure 15.5 tons / in2 (2,440 kg / cm2)
Approximate Barrel Life 5,000 rounds
Ammunition stowage per gun
  • British:
    • Danae and Emerald: 800 rounds
    • County class: 1,000 rounds
    • Monitors of World War I: 1,000 rounds
    • Others: N/A
  • Italian:
    • Navigatori: 1,500 rounds
    • Others: N/A
  • Russia: N/A
Complete breakdown of shell weight
Empty body 1.45 lbs. (0.66 kg)
Driving band 0.875 oz (0.025 kg)
Paint 0.125 oz (0.0035 kg)
Bursting charge 2.5 oz (0.071 kg)
Fuze No 131 5.25 oz (0.15 kg)
Total filled 2 lbs. (0.9 kg)


Range with 2.0 lbs. (0.9 kg) Shell
Elevation Distance
45 degrees 3,800 yards (3,475 m)
Maximum Effective Range 1,200 yards (1,100 m)
AA Ceiling N/A

The Italian shell was self-destructing at 4,900 yards (4,475 m), which implies that it had a range of at least that far.

Mount/Turret Data

  • British:
    • Mark II Gun: Mark II HA
    • Mark II*C Gun: Mark II*C HA
    • Mark XV 1
  • Italian: M1930
  • Russian: 40 mm Vickers Automatic
  • British:
    • Mark II: 1,568 lbs. (711 kg)
    • Mark II*C: 1,623 lbs. (736 kg)
    • M1930: 1,878 lbs. (852 kg)
  • Russian: 1,408.8 lbs. (639 kg)
Elevation -5 / +80 degrees
Elevation Rate Manually operated, only
Train 360 degrees
Train Rate Manually operated, only
Gun recoil N/A
  • ^Mark XV was a powered mounting similar to the Mark XVI mounting for the the 2-pdr. Mark VIII. Twenty-eight were produced during World War II and the surviving twenty-three were scrapped in early 1944.

Additional Pictures

External Pictures

The Vickers Photographic Archive
See Vickers Pom Pom and photograph numbers 2836 and 2837. (This is my best guess, but these last two photographs may actually be Mark VIII or Japanese guns)


Data from:

  • "The Italian Navigatori Class, 1926" article by Elio Andò in "Warship Special 2: Super Destroyers" edited by Antony Preston
  • "Big Gun Monitors: The History of the Design, Construction and Operation of the Royal Navy's Monitors" by Ian Buxton
  • "Naval Weapons of World War Two" by John Campbell
  • "L'artiglieria Italiana nella Grande Guerra" (Italian Artillery of the Great War) by Andrea Curami and Alessandro Massignani
  • "British Cruisers of World War Two" by Alan Raven and John Roberts
  • "Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland (Russian) Artillery) by A.V. Shirokorad


  • "Q.F. High Explosive 2 pdr Mark II N Shell - Forged Steel with Fixing Screw. Design." No. 21,071.c.(1) / A.D.G.S/3/164 dated 24 February 1916

Special help from Vladimir Yakubov, Caspar Vermeulen and Anthony G. Williams

Page History

02 March 2007
29 May 2010
Added notes on Mark I and Mark II*, fixed typographical error
29 August 2011
Added picture of River class destroyer
28 November 2015
Changed Vickers Photographic Archive links to point at Wayback Archive