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.

[1] 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.

[1] 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 and 1924.

Ammunition was of Fixed QF type and weighed between 20.4–29 kg (45–64 lb).