List of 120 mm Italian naval guns
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Italian 120 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 {{convert|9.7|kg|lb}} of smokeless powder to push a {{convert|23.49|kg|lb|adj=on}} projectile to a velocity of {{convert|950|m/s|ft/s}}. Velocity was later reduced to {{convert|920|m/s|ft/s}}, which gave a maximum range of {{convert|19.6|km|mi}} at 45° elevation or {{convert|18.2|km|mi}} 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.{{cite book |last=Campbell |first=John |title =Naval Weapons of World War Two |publisher =Naval Institute Press |date =1985 |location =Annapolis, Maryland |pages =335–338 |isbn =0-87021-459-4}}
40-caliber Armstrong 1889 and 1891
These were British QF Mark I and III guns used as coastal artillery and as star shell guns aboard Littorio-class battleships.
50-calibre M1909
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 {{convert|22.75|kg|lb|adj=on}} projectile at {{convert|840|m/s|ft/s}}.
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 {{convert|51|lb|kg|adj=on}} projectile at {{convert|750|m/s|ft/s}}. Range was {{convert|12.6|km|mi}} 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.
45-calibre Vickers Terni 1924
These guns were the main armament of Sauro-class destroyers. A charge of {{convert|7.6|kg|lb}} of smokeless powder pushed {{convert|51|lb|kg|adj=on}} projectiles at {{convert|850|m/s|ft/s}} to a range of {{convert|15.5|km|mi}} 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 {{convert|42.7|lb|kg|adj=on}} projectiles at a velocity of {{convert|730|m/s|ft/s}} to a ceiling of {{convert|7.8|km|ft}}.
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 {{convert|22|kg|lb|sing=on}} projectile at {{convert|730|m/s|ft/s}}. Range was {{convert|14|km|mi}} 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
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 {{convert|19.8|kg|lb|adj=on}} shell at {{convert|400|m/s|ft/s}} to an effective range of {{convert|4|km|mi}}.