During World War II in the Pacific, the ship's ten 40 mm gun mounts were crucial to her survival. Each gun mount had two barrels, and each barrel could fire 160 rounds per minute, with an effective range of 4 miles.

However, even this tremendous firepower was not always effective against enemy planes. Japanese suicide planes (kamikazes) hit 88 American destroyers - including CASSIN YOUNG - off Okinawa in World War II. 40 mm gun mounts with 4 barrels were added later.