Why an eighteen-inch gun has no clean development price

How much money would it take to develop an eighteen-inch naval gun?

There is no defensible single figure because heavy-gun development grew from continuing company research, competition, state funding, and later government purchases.

Large naval guns emerged from an ongoing industrial development stream rather than a clearly isolated project account. Private investment, competition among firms, direct state support, and production orders all contributed, making the true cost of a specific caliber nearly impossible to disentangle from the wider armaments enterprise.