The 65 mm gun filled the gap between a 57 mm 6-pounder considered too weak and a 76 mm 12-pounder considered too much for France's small destroyers. Choosing an intermediate calibre was intended to avoid the complication of carrying both larger and smaller gun types. The compromise helped define the armament of the Spahi generation, with six 65 mm guns aboard. It did not eliminate the other calibres from French use: 76 mm and 57 mm guns appeared anyway, alongside 40 mm weapons equivalent to 2-pounders.
Notable Point · 23:06-24:13
The 65 mm gun offers a compromise between two calibres
An intermediate 65 mm gun was meant to balance hitting power and hull limits while avoiding two gun types, but France eventually used the other calibres too.