[Brad from Tennessee]

FROM WIKIPEDIA: . . .USS Iowa‍ '​s main battery consisted of nine 16" (406.4mm)/50 caliber Mark 7 guns, which could fire 2,700 lb (1,200 kg) armor-piercing shells 20 nmi (23 mi; 37 km). Her secondary battery consisted of twenty 5 in (130 mm)/38 cal guns in twin mounts, which could fire at targets up to 12 nmi (14 mi; 22 km) away. With the advent of air power and the need to gain and maintain air superiority came a need to protect the growing fleet of Allied aircraft carriers; to this end, Iowa was fitted with an array of Oerlikon 20 mm and Bofors 40 mm anti-aircraft guns to defend Allied carriers from enemy airstrikes.[4]

[Ancesthntr]

FYI, the Montana class ships were to be next - 4 turrets of 3 16” guns, instead of 3, plus heavier armor. The ideas was scrapped to have the necessary metal for aircraft carriers instead.

Oh, would I have liked to have seen the USS Montana!