Could a 12-inch flak gun work?

Could a 12-inch gun be used as a flak cannon?

Possibly in principle, although even an autoloading version would need about six barrels to sustain a useful rate of fire.

The idea is treated as an engineering problem rather than dismissed outright. Shell and loading weight would make rate of fire the central constraint even with automatic loading. The estimate is at least six barrels, arranged as three twin mounts or two triples. Anti-aircraft effectiveness would depend on the volume and timing of fire rather than projectile size alone.