What initiates the incendiary composition of the 20 mm API round?

The incendiary composition of the 20 mm Armor-Piercing Incendiary (API) round is initiated by impact. When the round strikes a target, the force from the collision activates the incendiary materials contained within the projectile. This mechanism is designed to ignite and produce flames upon impact, contributing to the round's effectiveness against armored targets by not only penetrating but also igniting flammable materials or causing secondary explosions.

In understanding how the incendiary round operates, it's essential to note that the activation relies on the physical impact that occurs during the round's detonation process. This ensures that the incendiary effect is delivered at the moment of contact, making it a critical feature of the API's design and intended functionality.