Armour-piercing ammunition

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Armour-piercing ammunition

• Top left: Solid shot armour-piercing projectiles stuck in armour plate
• Top right: Projectile penetration animation
• Lower left: Perforated 110 mm (4.3 in) armour plate, penetrated by 105 mm (4.1 in) armour-piercing solid shot projectile
• Lower right: Diagram of capped armour-piercing shell:
  • 1. – Ballistic cap or armour-piercing cap
  • 2. – Steel alloy kinetic energy penetrator
  • 3. – Desensitized high explosive bursting charge
  • 4. – Base-fuse (set with delay to explode inside the target)
  • 5. – Bourrelet (front) and driving band (rear)

Armour-piercing ammunition (AP) is a type of projectile designed to penetrate armour protection, most often including naval armour, body armour, vehicle armour.^[1]

The first major application of armour-piercing projectiles was to defeat the thick armour carried on many warships and cause damage to their lightly armoured interiors. From the 1920s onwards, armour-piercing weapons were required for anti-tank warfare. AP rounds smaller than 20 mm are intended for lightly armoured targets such as body armour, bulletproof glass, and lightly armoured vehicles.

As tank armour improved during World War II, anti-vehicle rounds began to use a smaller but dense penetrating body within a larger shell, firing at very high muzzle velocity. Modern penetrators are long rods of dense material like tungsten or depleted uranium (DU) that further improve the terminal ballistics.