Type 96 25mm Anti-Aircraft Gun

The Type 96 25mm Gun (九六式二十五粍高角機銃 Kyūroku-shiki nijyūgo-miri Kōkakukijū) was an automatic cannon used by the Imperial Japanese Navy during World War II. A locally-built variant of the French Hotchkiss 25mm anti-aircraft gun, it was designed as a dual-purpose weapon for use against armored vehicles and aircraft, but was primarily used as an anti-aircraft gun in fixed mounts with between one and three guns. The Type 96 25mm Gun is a simple air-cooled gas operated design. The barrel is a forging screwed into the breech mechanism. Additional support is provided to the breech end of the gun barrel by the finned cooling jacket. The barrel is changeable, requiring two men and special tools to complete, and took a trained crew approximately five minutes. By adjusting the gas valve setting it was possible to vary the rate of fire between 200 and 260 rounds per minute, with 220 rounds per minute being the standard setting. The gun mounts were normally provided with one of three gun sights: A Le Prieur mechanical lead computing sight, an open ring sight, or an etched glass optical ring sight.

Land mountings and all single mountings all used the single open-ring sight. The Type 96 sight was used on ship-based multiple mounts, in the case where the mount has a powered drive linked to a fire director it was used as a backup.

The Type 96 sight was originally designed with a maximum target speed of 600 kilometers per hour; however, experience showed that aircraft often exceeded this speed. To compensate for the problem a ring was added to the sighting telescope to provide an additional offset for speeds up to 900 kilometers per hour.

The gun was normally used without a gun shield, although some multiple mounts on Yamato-class battleships were fitted with Ducol (High tensile steel) shields. Many ship-based mounts also had splinter shields.

The Type 96 cartridge case was a rimless type design with a deep extraction groove at the base. The projectiles fired by the weapon were slightly unusual in that they had two rotating bands. The forward band was slightly smaller in diameter than the rear band. It was believed that this was to reduce wear on the rifling near the chamber. The case of the cartridge was crimped around the rear rotating band. The complete round weighed approximately 820 g (1.81 lb) with the projectile weighing 320 g (0.71 lb).

The propellant was 102 grams of single-perforated, graphited grains of nitrocellulose approximately 2 millimeters in diameter and between 2.5 and 4.5 millimeters in length.

Normally one tracer round was added every four or five rounds to aid laying.
 * High-explosive shells. Orange body.
 * High explosive incendiary. Green body.
 * High explosive tracer. Orange or red body.
 * High explosive tracer self-destroying. Orange or red body.

Amagi and Hidioame both carried these AA guns. Amagi 's contingent went to USS Walker, and it is alluded that the batch from Hidioame went to the Khonashis.
 * Armor-piercing. Black, white or smoky blue body. Approx 42mm penetration at 0-100m and 0 degrees from normal.