Would a 13.5-inch 50-calibre gun appear in this timeline?
Short answerProbably not; Britain would more likely improve the 45-calibre weapon because its slower wear better suited global operations.
NotesThe preference is to improve the 45-calibre gun rather than move to a 50-calibre weapon. A longer gun offers more performance, but faster wear would require more frequent barrel replacement. That support burden matters to a navy operating worldwide. Vickers could continue developing the established weapon while preserving the availability valued by the Royal Navy. Supercharging is mentioned as a further complication to the comparison, so barrel length alone does not settle every later choice.