15 cm/50 41st Year Type
The was a naval gun used by the Imperial Japanese Navy before and during World War II. It had a bore with a length of (50 calibre) and fired shell for a distance of (in single mount version) or (in the later twin mounts). The gun was first used in single casemates on the Kongō-class battlecruisers and Fusō-class battleships and later in the Agano-class light cruisers in twin mountings. History. The Type 41 was a Japanese version of the Vickers "Mark M", originally introduced by Vickers-Armstrong (Barrow) as the secondary battery  for the Kongō-class. These original guns were designated by the Japanese Navy as the "Mark II", whereas the Japanese-designed copy (adopted from 1912) were designated as the "Mark III". In the 1930s, the Kongō-class were modernized, at which time these guns were replaced by new 12.7 cm/40 DP guns. The old guns were placed in storage and were reused on the Agano-class. Some were taken to Guam and were used for coastal defense batteries. In the Agano-class, the gun could elevate to 55° for anti-aircraft fire; however, its manual loading method allowed a  rate of fire of only about 6 rounds per minute, which significantly limited its utility as an anti-aircraft weapon.