Why bigger battleship guns were not automatically better

How should battleship gun size be balanced against rate of fire?

The proposed 16.5-inch G3 gun was near a practical sweet spot: larger weapons improved penetration but fired too slowly for effective spotting correction, while smaller guns risked inadequate penetration against heavy armour.

The comparison places the proposed British 16.5-inch G3 gun near a practical middle ground between lighter rapid-firing weapons and very heavy guns. Larger shells gain penetration, but slow fire produces fewer fall-of-shot observations for correcting aim while both ships move. Smaller 12- and 14-inch calibres may fire rapidly yet struggle against the heaviest armor, with Yamato-level protection used as the example. Effective gunnery therefore depends on range, accuracy, penetration, and repeated hits as well as the nominal power of one shell.