Information on the guns on the Iowa class that are shelling japan.
https://en.wikipedia.org/wiki/16%22/50_caliber_Mark_7_gun
Several years ago I read a “what if” matchup between Iowa class and Yamato class battleships. The author gave the edge to Iowa, mostly because the American 16/50 was considered superior to the Japanese 18.1/45. While the Yamato’s guns had greater range and throw weight, the American gun was considered as part of a total weapons system. The Iowa had a slightly higher rate of fire, and had better rangefinding, including radar plot. Not necessarily part of the gun system, the Iowa class was faster, more maneuverable, and a more stable gun platform. The greater range for Yamato was discounted as the effective range for a battleship duel was considered far less than maximum range.
It was a duel that could have happened at the Battle of Leyte Gulf.