View source for 320 mm Model 1934 naval gun

{{Infobox weapon
| name = ''Cannone navale da 320''
| image = RNCavour-Napoli.jpg
| image_size = 300
| caption = This photo shows the typical fore-and-aft installation of a twin turret superfiring over a triple turret.
| origin = Italy
| type = [[Naval gun]]
<!-- Type selection -->
| is_ranged = YES
| is_bladed =
| is_explosive =
| is_artillery = YES
| is_vehicle =
| is_UK =
<!-- Service history -->
| service = 1937&nbsp;– 1956{{sfn|Breyer|1973|pp=374–380}}
| used_by = {{unbulleted list
| Regia Marina
| Soviet Navy
| Italian Navy
}}
| wars = [[Second World War]]
<!-- Production history -->
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<!-- General specifications -->
| weight = 64 tonnes{{sfn|Campbell|1985|pp=322–324}}
| length =
| part_length = 14 meters (550 inches){{sfn|Campbell|1985|pp=322–324}}
| width =
| height =
| crew =
<!-- Ranged weapon specifications -->
| cartridge = {{convert|525|kg|lb|sigfig=3}}{{sfn|Campbell|1985|pp=322–324}}
| caliber = {{convert|320|mm|in|sigfig=3|abbr=on}}{{sfn|Campbell|1985|pp=322–324}}
| action =
| rate =
| velocity = 830 meters per second (2,700 ft/sec){{sfn|Campbell|1985|pp=322–324}}
| range =
| max_range = {{convert|30|km|mi}}{{sfn|Campbell|1985|pp=322–324}}
| feed =
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}}
The '''320&nbsp;mm naval gun''' was the main battery gun used to modernize Italy's [[World War I]] [[battleship]]s for service during [[World War II]].{{sfn|Breyer|1973|pp=374–380}} The guns were manufactured by boring out and relining the battleships' original [[305 mm /46 Model 1909|12"/46 (30&nbsp;cm)]] [[built-up gun]]s and modifying the turrets to increase elevation above the original 20°&nbsp; maximum. Each ship carried two 548-tonne twin turrets and two 745-tonne triple turrets. All guns used pneumatically operated side-swing [[Welin breech block]]s. Each barrel could fire two rounds per minute.{{sfn|Campbell|1985|pp=322–324}}
In service these guns chronically suffered of great horizontal dispersion, both from the worsened thermodynamic performance of the guns themselves and from the unequal quality of the shells fired.<ref>{{cite web|last1=Piccinotti|first1=Andrea|title=Cannoni|url=http://www.regiamarinaitaliana.it/Cannoni.html|website=REGIA MARINA ITALIANA|access-date=7 February 2015|archive-url=https://web.archive.org/web/20140616063211/http://www.regiamarinaitaliana.it/Cannoni.html|archive-date=16 June 2014|url-status=dead|df=dmy-all}}</ref>
==M1934 guns==
The {{sclass|Conte di Cavour|battleship|2}}s {{ship|Italian battleship|Conte di Cavour||2}} and {{ship|Italian battleship|Giulio Cesare||2}} originally mounted 13 guns as built in 1915 and 1914. These ships were rebuilt between 1933 and 1937 by removing the Q triple turret amidships and replacing guns in triple A turret, twin B and X turrets, and triple Y turret. ''Conte di Cavour'' carried [[Vickers]] Mk G guns while ''Giulio Cesare'' carried Pattern T guns built by [[Elswick Ordnance Company]]. [[Oto Melara|Odero Terni Orlando]] (OTO) re-bored the Vickers guns while the Elswick guns were re-bored by [[Gio. Ansaldo & C.]] Maximum gun elevation was increased to 27°.{{sfn|Campbell|1985|pp=322–324}}
==M1936 guns==
The {{sclass|Andrea Doria|battleship|2}}s {{ship|Italian battleship|Andrea Doria||2}} and {{ship|Italian battleship|Duilio||2}} originally mounted 13 guns as built in 1916 and 1915. These ships were similarly rebuilt between 1937 and 1940 by removing Q turret and replacing guns in A, B, X, and Y turrets. Pattern T guns aboard ''Duilio'' were similarly rebuilt by Ansaldo while Mk G guns aboard ''Andrea Doria'' were rebuilt by OTO. Maximum gun elevation was increased to 30°.{{sfn|Campbell|1985|pp=322–324}}
==Ammunition==
The gun was loaded with four cloth bags each containing {{convert|44|kg}} of [[smokeless powder]]. High explosive (HE) shells weighed only {{convert|458|kg|lb|sigfig=3}}. Anticipated useful barrel life was 150 [[List of British ordnance terms#Effective Full Charge|effective full charge]]s (EFC).{{sfn|Campbell|1985|pp=322–324}}
==References==
;Notes
{{reflist}}
; Bibliography
* {{cite book | title = Battleships and Battle Cruisers 1905–1970 | last = Breyer | first = Siegfried | publisher = Doubleday and Company | year = 1973 | isbn = 0-385-07247-3 }}
* {{cite book | title = Naval Weapons of World War Two | last = Campbell | first = John | publisher = Naval Institute Press | year = 1985 | isbn = 0-87021-459-4 }}
==External links==
{{Use dmy dates|date=June 2017}}
* [http://www.navweaps.com/Weapons/WNIT_126-44_m1934.php NavWeaps - 320mm/44 Model 1934]
[[Category:Naval guns of Italy]]
[[Category:World War II weapons of Italy]]
[[Category:World War II artillery of Italy]]
[[Category:320 mm artillery]]
[[Category:World War II naval weapons]]
[[Category:Gio. Ansaldo & C. artillery]]