The gun was first deployed in 1971 as the Mk 45 Mod 0, and has been updated in the more than five decades since.

The enormously destructive power of the big gun at close ranges ... will lead to the elimination from the main batteries of future battleships of mixed batteries of 6-inch, 7-inch, 8-inch ...

KURE, Hiroshima Prefecture--A massive lathe used to precision shape the main gun barrels of Japan’s mighty World War II battleship Yamato is now on public display at the Kure Maritime Museum here.