Why did France adopt another battleship gun calibre instead of standardising on an existing heavy weapon?
Short answerThe domestic gun was available and workable, while importing British 14-inch weapons offered commonality but conflicted with political and industrial preferences.
NotesIndustrial readiness favoured the chosen French heavy gun because it could be built and made to work at the required time. A larger or different calibre might improve the ship on paper, but it would add development risk and another ammunition system. Buying British 14-inch guns could produce a powerful ship with only limited redesign. National pride and the desire for domestic weapons made that politically unattractive. A later comment returns to the logistical cost of adopting a separate calibre and notes that French procurement sometimes prioritized politics over ammunition commonality. Gun diameter becomes an example of how industrial capacity, standardisation, logistics, and sovereignty pull a capital-ship programme in different directions.