Italian120 millimetre naval guns were standard main armament on Italian destroyers and were widely used on various other ships and coastal artillery. The 50-calibre guns used a charge of of smokeless powder to push a projectile to a velocity of. Velocity was later reduced to, which gave a maximum range of at 45° elevation or at 35° elevation. Variants of similar designs were built by Ansaldo, OTO, Vickers, Schneider, Canet and Armstrong. Older and shorter-barreled guns have different ballistics as noted below. .
These guns formed the original secondary battery of Andrea Doria and Conte di Cavour-class battleships and were later used for coastal artillery. They fired a projectile at.
45-caliber Armstrong 1918
These guns were developed from the older 40-calibre models and installed as coastal artillery and aboard troopships and armed merchant cruisers. They fired a projectile at. Range was at the maximum elevation of 30° .
45-calibre Schneider-Canet-Armstrong 1918
These guns with a maximum elevation of 30° were installed as coastal artillery and aboard auxiliary ships.
45-calibre Schneider-Canet-Armstrong 1918/19
This gun was a twin mounting of the 1918 gun with maximum elevation increased to 32° . These guns were the main armament of Leone class destroyers and the sloop Eritrea.
These guns were the main armament of Sauro-class destroyers. A charge of of smokeless powder pushed projectiles at to a range of at the maximum elevation of 33° ; but dispersion was increased by using a common cradle for the 16.6-ton twin mount.
27-calibre OTO 1924
These were the original deck guns aboard Ettore Fieramosca and Balilla-class submarines. When replaced by the 45-caliber OTO 1931, these guns were installed as an anti-aircraft battery at Messina where they fired projectiles at a velocity of to a ceiling of.
45-calibre OTO 1926
These guns were the OTO version of the Vickers Terni 1924 guns. Turbine-class destroyers were built with these guns as the main armament, and Sella-class destroyers were re-armed with these guns.
50-calibre Ansaldo 1926
These horizontal sliding breech block guns in 20-tonne common-cradle twin mountings with maximum elevation of 45° were the main armament of Navigatori, Freccia and Folgore-class destroyers.
45-calibre OTO 1931
These 3.2-ton quick-firing guns with a horizontal sliding breech block were mounted aboard Ettore Fieramosca, Pietro Micca, Balilla-class and Calvi-class submarines. They fired a projectile at. Range was at the maximum elevation of 32° .
50-calibre OTO 1931
These horizontal sliding breech block guns in common-cradle twin mountings with maximum elevation of 33° were the main armament of Maestrale-class destroyers.
50-calibre OTO 1933
These horizontal sliding breech block guns in 34-tonne common-cradle twin turrets with maximum elevation of 42° formed the secondary battery of the rebuilt Conte di Cavour-class battleships.
15-calibre OTO 1933 and 1934
These were star shell howitzers installed aboard Zara-class cruisers and Maestrale, Oriani and Soldati-class destroyers. The guns elevated to 50° to fire a shell at to an effective range of.
50-calibre OTO 1936
These horizontal sliding breech block guns in common-cradle twin mountings weighing 22.8 tonnes with maximum elevation of 35° were the main armament of Oriani-class destroyers.
50-calibre Ansaldo 1936
These horizontal sliding breech block guns in common-cradle twin mountings weighing 21.6 tonnes with maximum elevation of 40° were the main armament of some Soldati-class destroyers.
50-caliber Ansaldo 1937
These horizontal sliding breech block guns in common-cradle twin mountings weighing 21.6 tonnes with maximum elevation of 42° were the main armament of other Soldati-class destroyers.
50-caliber Ansaldo 1940
These horizontal sliding breech block guns in 12-tonne single mounts with maximum elevation of 45° replaced the star shell howitzer of Soldati-class destroyers Bombardiere, Camicia Nera, Carabiniere, Corsaro, Geniere, Lanciere, Legionario, and Mitragliere.
