BAE's recurring 14-inch naval-gun concept

If BAE builds a 350 mm naval gun, would it be a railgun and what size ship could carry it?

Neither the mechanism nor a viable ship displacement is established; the response concerns recurring interest in roughly 350-360 mm guns.

The question asks whether a roughly 14-inch naval gun would be electromagnetic and what displacement could carry it as a viable warship. Neither point receives a technical answer. Instead, the focus is recurring interest in weapons around 350-360 mm and a joke comparing BAE's salesmanship with Vickers. No mechanism, mounting, or host design is specified.