A hypothetical World War II ship with 90 guns might have only six 6-inch guns, with the rest of the total including 40 mm weapons, 20 mm weapons, and machine guns. In a ship-to-ship gunnery duel, those six main guns usually provide the most relevant description of its armament. Lighter weapons can take part at very close range or against motor torpedo boats and aircraft, so their importance depends on the opponent and circumstances. Historians therefore identify the ship type and principal calibre, for example a cruiser with 6-inch or 8-inch guns. This longer description preserves distinctions between weapons that a single total would hide.
Notable Point · 1:20-2:22
Why main-battery calibre matters in a gunnery duel
For a modern warship, its role and principal battery, such as 6-inch or 8-inch cruiser guns, reveal more than a total that mixes many weapon types.