The American 4-inch Mark IX had entered service in 1914 and still fired only eight to nine rounds per minute without the sustained mechanical development given to British 4-inch weapons. Many flush-deck destroyers transferred to Britain were rearmed, usually with British guns, and transferred escort carriers also received replacement weapons. The old gun retained respectable armor penetration, but its handling and mechanisms had fallen behind. Those shortcomings reveal funding choices that fleet totals alone conceal. Flush-deck destroyers remained useful in secondary roles in 1942 and afterward, so their neglected armament continued to matter.
Notable Point · 20:45-24:51
The neglected US Navy 4-inch gun
A capable First World War-era US gun became obsolete through neglect, exposing the hard funding choices beneath interwar fleet totals.