120 mm 50 caliber Pattern 1905

120 mm 50 caliber Pattern 1905
An open twin-mount Pattern 1905 in Finnish service.
Type	Naval gun Coastal artillery Railway artillery
Place of origin	Great Britain
Service history
In service	1905-1950's
Used by	Russian Empire Soviet Union Finland
Wars	World War I Russian Civil War Winter War World War II
Production history
Designer	Vickers
Designed	1905
Manufacturer	Vickers Obukhov State Plant
Produced	1905
No. built	210
Specifications
Weight	3.1 t (3.4 short tons)
Length	6 m (19 ft 8 in) 50 caliber
Barrel length	5.8 m (19 ft 0 in)
Shell	Fixed QF ammunition
Shell weight	20.4–29 kg (45–64 lb)
Calibre	120 mm (4.7 in)
Elevation	Single mount: -10° to +20° Twin mount: -3° to +27°
Traverse	360°
Rate of fire	6-7 rpm
Muzzle velocity	792 m/s (2,600 ft/s)
Maximum firing range	13.7 km (8.5 mi) at +20°

The 120 mm 50 caliber Pattern 1905 was a Russian naval gun developed by Vickers for export in the years before World War I that armed a variety of warships of the Imperial Russian Navy. Guns salvaged from scrapped ships found a second life as coastal artillery, railway artillery and aboard river monitors during the Russian Civil War. It was estimated that there were 110 guns in the Soviet Navy's inventory in 1941. Of these, 39 were in the Baltic Fleet, 20 in the Black sea Fleet, 24 in the Amur Flotilla, 11 in the Pacific Fleet and 6 in the Pinsk flotilla in World War II.

The Pattern 1905 began life as a Vickers design produced in Great Britain for export customers. The Pattern 1905 was also produced under license at the Obukhov State Plant in St. Petersburg, Russia.

The Pattern 1905 was a built-up gun which consisted of an A tube, three layers of reinforcing tubes, a jacket and a breech piece which screwed onto the jacket. Once Obhukov started production the Vickers guns were referred to as model 1 guns, while those manufactured by Obukhov were referred to as model 2 guns. By 1918 it was estimated that 180 guns had been completed with another 20 partially complete. A few more were finished between 1921-24 from existing stocks.

The Pattern 1905 guns armed armored cruisers, dreadnought battleships, gunboats, icebreakers and river monitors of the Imperial Russian Navy and Soviet Navy built or refit between 1905-1924.