Using the 15-inch/50 could have reduced some weights, reused proven shell stocks, and encouraged a common calibre across older and future British battleships. The longer barrel promised a meaningful performance increase without abandoning the established 15-inch projectile family. The drawback was strategic presentation: an F3 with nine advanced 15-inch guns would appear to be the navy's strongest ship, weakening the claim that still more powerful battleships waited with the Home Fleet. Choosing 16-inch guns for the home-force ships restored a visible hierarchy between the traveling fast squadron and the battle line. Calibre therefore formed part of a deterrent concept of operations as well as a gun-performance calculation.
Notable Point · 1:30:44-1:37:18
Why Britain chose 16-inch guns over the logical 15-inch/50
A new 15-inch/50 offered logistical and ballistic advantages, but 16-inch guns better preserved the intended contrast between fast ships shown abroad and a visibly heavier battle fleet held at home.