Guided shells from large-calibre guns

The thought experiment concentrates on gun barrels, automatic loading and fire control, then opens with guided ammunition. A sabot or discardable outer section could shield delicate guidance fins from the violence of launch. A 16-inch gun might fire a smaller guided projectile inside a protective package, or discard only a rear section before deploying fins. The projectile would sacrifice some mass, but a much higher hit probability could more than compensate. Modernising a battleship gun would involve ammunition, sensors and loading machinery as much as barrel size.