The discussion begins from the relatively slow fire of wartime American 8-inch mountings compared with some foreign cruiser guns. The checked figures place the older Mark 12 and Mark 15 weapons at roughly three to four rounds per minute. The autoloading Mark 16 fitted to the postwar Des Moines class could reach about ten rounds per minute. That improvement greatly increased the weight of shells a heavy cruiser could put on a target in a minute. The comparison shows why loading machinery, not calibre alone, determines a cruiser's practical volume of fire.
Notable Point · 5:20:42-5:23:22
How autoloading transformed the US 8-inch gun
The Des Moines class's autoloading Mark 16 raised 8-inch fire from roughly three or four rounds per minute to about ten, addressing a wartime US cruiser weakness.