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 (AP) ammunition is a type of projectile designed to penetrate armour, including naval armour, vehicle armour, and body armour.
Armour-piercing ammunition was developed in the late 19th century to defeat the armour of ironclad warships and later, during the 20th century, became a key component of anti-tank warfare. AP ammunition evolved from hardened full-calibre steel shot and shell to include sub-calibre kinetic energy penetrators such as armour-piercing discarding sabot (APDS) and armour-piercing fin-stabilized discarding sabot (APFSDS), as armour technology advanced.
Armour-piercing ammunition comprises a variety of projectile designs for use against different targets and armour types, ranging from small-arms ammunition to large-calibre tank and naval gun projectiles. Modern kinetic-energy penetrators are typically made from dense materials such as tungsten heavy alloys or depleted uranium.