Using 76 mm naval guns against drone swarms

Could World War II-style flak concepts be useful against modern drone swarms?

Yes; modern 76 mm fire can provide a valuable medium-range layer when assessed against the damage it prevents.

Modern 76 mm guns combine range, destructive effect, and rate of fire that can help intercept cheaper drones before they get close enough to cause damage. The Italian Navy's practice of fitting several such guns provides the example, while Type 31 illustrates the wider return to gun-based defence. The 76 mm calibre is also identified as three inches, historically associated with the 12-pounder. The economic comparison includes the damage an attack could cause to the ship or another protected target. Even an expensive interception can be justified if it prevents much greater losses.