Gunnery tailored for close, fast Mediterranean battles

Italian designers expected close, fast-moving engagements in the Mediterranean and Adriatic rather than the more distant battle often imagined for open oceans. That tactical expectation informed the choice of a 40-calibre 15-inch gun, contrasted here with the Royal Navy's longer 42-calibre weapon. The shorter gun was meant to help the mounting train and settle onto a target more quickly during a swirling engagement. Even a small saving mattered if it increased the chance of firing the first effective salvo. Gun length here follows from a navy's expectations about geography, battle range, and the tempo of combat.