Were large American guided naval shells already tried?

Were there American experiments with 406 mm guided shells in the 1950s and 1960s?

Those experiments are not confirmed; an 8-inch Paveway shell is recalled as a fielded example, with an explicit qualification about the participant's knowledge.

The proposed American 406 mm experiments are left unconfirmed. A recollection of another project is withdrawn because it concerned gun barrels. An 8-inch Paveway shell for the lightweight 8-inch gun is recalled as a fielded example, expressly qualified as being to one participant's knowledge.