320 mm Model 1934 naval gun

Cannone navale da 320
This photo shows the typical fore-and-aft installation of a twin turret superfiring over a triple turret.
TypeNaval gun
Place of originItaly
Service history
In service1937 – 1956[1]
Used by
  • Regia Marina
  • Soviet Navy
  • Italian Navy
WarsSecond World War
Specifications
Mass64 tonnes[2]
Barrel length14 meters (550 inches)[2]

Shell525 kilograms (1,160 lb)[2]
Caliber320 mm (12.6 in)[2]
Muzzle velocity830 meters per second (2,700 ft/sec)[2]
Maximum firing range30 kilometres (19 mi)[2]

The 320 mm naval gun was the main battery gun used to modernize Italy's World War I battleships for service during World War II.[1] The guns were manufactured by boring out and relining the battleships' original 12"/46 (30 cm) built-up guns and modifying the turrets to increase elevation above the original 20°  maximum. Each ship carried two 548-tonne twin turrets and two 745-tonne triple turrets. All guns used pneumatically operated side-swing Welin breech blocks. Each barrel could fire two rounds per minute.[2]

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.[3]

  1. ^ a b Breyer 1973, pp. 374–380.
  2. ^ a b c d e f g Campbell 1985, pp. 322–324.
  3. ^ Piccinotti, Andrea. "Cannoni". REGIA MARINA ITALIANA. Archived from the original on 16 June 2014. Retrieved 7 February 2015.