Alex Clarke recalls an archival reference to a British 20-inch/54 naval gun associated with 1919. Whether it was actually built and tested remains uncertain because surviving information is incomplete. His inference rests on wording about excessive barrel weight and drooping, which he thinks suggests a physical trial. That remains an interpretation of a limited reference, rather than confirmation that a workable gun existed.
Notable Point · 7:05:05-7:06:03
The uncertain evidence for a British 20-inch/54 gun
An archival reference suggests an exceptionally large British gun project, but construction and testing are explicitly uncertain.