page_title: Type 96 25 mm AT/AA Gun
section_title: Design
hierarchical_section_title: Type 96 25 mm AT/AA Gun / Design
caption_attribution_description: A Japanese mechanical lead computing sight mounted on a Type 96 25 mm machine gun triple mount (whited out of the picture). Note that it is used with a small sighting telescope instead of the more usual open ring.
context_page_description: The Type 96 25mm Gun 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 one to three guns.
context_section_description: 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; the operation 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
  An etched glass optical ring sight
  Land mountings and all single mountings all used the single open-ring sight. The Type 95 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 95 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.
caption: The Le Prieur mechanical lead computing sight.
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