The Cannone da 381/50 Ansaldo M1934 was a 381-millimeter (15.0 in), 50-caliber naval gun designed and built for the Royal Italian Navy (Regia Marina) by Gio. Ansaldo & C. in the 1930s. The gun served as the main armament of Italy's last battleships, the Littorio class. These built-up guns consisted of a liner, a cylinder over the chamber and part of the rifle bore, a full-length cylinder, and a 3/4 length jacket with a hydro-pneumatically operated side-swinging Welin breech block. Each battleship carried nine guns mounted in three triple turrets with maximum elevation of 35°. Time between salvos was approximately 45 seconds.