Gun caliber does not locate a battlecruiser on the spectrum

Does gun caliber show whether a battlecruiser sits nearer the battleship or cruiser end of the spectrum?

No; navies often reused contemporary battleship guns for economy, so mission, protection, structure, and speed are more revealing than caliber alone.

Mission and overall design balance matter more than gun caliber. Battlecruisers commonly reused the guns already being built for contemporary battleships because common production was cheaper and simpler. A large weapon need not imply battleship structure, protection, or employment. German efforts to tailor different guns to individual designs also carried an industrial cost.