Historical 4.5-inch installations revealed handling difficulties when the weapon entered operational use. In this counterfactual, live-fire exercises and several extra prewar years make those faults visible sooner. Carrier installations had more room and time for their crews, whereas destroyer service exposed the ammunition burden more sharply. The Royal Navy's training budget and exercise routine make correction before 1939 plausible, although other engineering compromises would remain.
Chapter · 35:41-37:10
Prewar exercises expose mount and ammunition problems
Earlier deployment gives Royal Navy exercises time to uncover heavy-ammunition and mount problems before wartime service.