A larger gun does not automatically provide a worthwhile intermediate step. The 10-inch example combines support costs approaching those of a 12-inch weapon with little firing-rate advantage, while a 9.2-inch gun offers faster fire and nearly as much effect. The discussion applies a similar argument to bypassing 19.5-inch guns in favor of 21 inches. Weapons that large would require heavily mechanized loading, which is distinguished from automation. A separate design comparison asks whether eight 18-inch guns or potentially twelve 16.5-inch guns would make better use of the same displacement.
Notable Point · 2:28:11-2:31:06
Why some gun calibres offer a poor compromise
Support costs and firing rate can make an intermediate calibre unattractive, while very large guns demand increasingly mechanized loading.