Early autoloader attention clustered around eight-inch and larger weapons because human crews already sustained high rates with six-inch, 4.7-inch, and similar shells. A machine therefore had to beat skilled loaders instead of making an otherwise impossible movement. In Royal Navy experiments during the 1930s, the humans were still faster, weakening the value-for-money case for automating smaller guns.
Notable Point · 2:28:37-2:30:08
Why interwar autoloaders focused on larger guns
Below heavy-cruiser caliber, 1930s machinery often had to compete with human crews that could already load the weapons faster.