Imperial Japanese Navy Ammunition - 25mm Projectiles

Imperial Japanese Navy Ammunition

25mm Ammunition

 

 

The only 25mm gun in use by the Japanese was the Type 96 Model 2 anti-aircraft/anti-tank gun.  This multiple-barreled, air-cooled, magazine-fed, automatic weapon.

 

Case: The case is rimless; has a slight taper and a pronounced neck, which is crimped over the "after" rotating band of the projectiles.

 

Length: 6.46 inches

Diameter of base: 1.65 inches

Material: Brass

Weight (empty): 333.5 grams

 

Propellant: The propellant is single-perforated, graphited grains of nitrocellulose.  The grains are 2mm in diameter and from 2.5mm to 4.5mm in length.  The propellant weight is 102 grams.

 

Projectiles: The type of projectile is indicated by painting the projectile body a solid color.

 

The following dimensions are common to all projectiles:

Projectile diameter: 0.96 inch (24.5mm)

Width of rotating bands:

-Forward: 0.71 inch

-Aft: 0.24 inch

 

 

 

25mm High-Explosive Projectile

 

Fuzing: Model 1 or Model 4

Weight of projectile, filled (without fuze): 7.04 oz

Weight of projectile filling: 0.54 oz

 

Fillings:

-Standard: TNT, 66%;  Aluminum, 34%

-Alternates: Cast TNT or Tetryl

 

Dimensions:

-Length of projectile (without fuze): 3.58 inches

-Length of assembled round: 8.27 inches

 

Color and markings: Maroon overall

 

 

 

25mm High-Explosive Incendiary Projectile

 

Fuzing: Model 1 or Model 4

Weight of projectile, filled (without fuze): 7.17 oz

Weight of projectile filling: 0.67 oz

 

Filling:

-TNT and aluminum: 0.2 oz

-White Phosphorous: 0.47 oz

 

Dimensions:

-Length of projectile (without fuze): 3.58 inches

-Length of assembled round: 8.27 inches

 

Color and markings: Green overall

 

 

 

25mm High-Explosive Tracer Projectile

 

 

Fuzing: Model 1 or Model 4

Weight of projectile, (approximately) filled (without fuze): 4.16 oz

Weight of projectile filling (including tracer): 0.72 oz

 

Fillings: H.E.T.

-Standard: Three pellets of TNT and aluminum

-Alternates: Three pellets of TNT;  Cast or pressed tetryl

 

Dimensions:

-Length of projectile (without fuze): 3.43 inches

-Length of assembled round: 8.24 inches

 

Color and markings: Orange or Red overall

 

Remarks: The only discernible difference between the orange and red rounds is a slight disagreement in weight.

 

  

 

25mm High-Explosive Tracer (Self-Destroying) Projectile

 

 

Fuzing: Model 1 or Model 4

Weight of projectile, filled (without fuze): 4.16 oz

Weight of projectile filling: 0.72 oz

 

Filling: TNT and aluminum with a black powder core in the lower pellet.

 

Dimensions:

-Length of projectile (without fuze): 3.43 inches

-Length of assembled round: 8.24 inches

 

Color and markings: Red overall

 

Remarks: There is no external marking to distinguish the self-destroying rounds from those that are not self-destroying.

 

 

 

25mm Armor-Piercing Projectile

  

 

Fuzing: None

Weight of projectile, filled (without fuze): 8.88 oz

Weight of projectile fillings:

-Tracer: 3.05 oz (8.64 grams)

-Inert Material: 1.25 oz (3.53 grams)

 

Filling:

-Tracer: Sodium nitrate, magnesium and barium peroxide

-Inert Material: Kieselguhr (chiefly dry clay)

 

Dimensions:

-Length of projectile (without fuze): 3.93 inches

-Length of assembled round: 8.74 inches

 

Color and markings: Black, white, or smoky blue overall

 

Remarks: This projectile is listed in Japanese as armor-piercing, although the metal is softer than that used in smaller A.P. rounds.

 

 

 

Next Time: 30mm, 40mm, and 50mm Projectiles