Final answer:
An Armor-Piercing (AP) cartridge is a bullet used in firearms designed to penetrate armor and is typically made with a dense core to maintain its trajectory and a soft outer jacket to protect the firearm's barrel.
Step-by-step explanation:
An Armor-Piercing (AP) cartridge is a type of bullet used in firearms designed to penetrate armor or protective cover. These cartridges are made with a hard, dense core material, often of depleted uranium or tungsten, enclosed in a softer outer jacket. The dense core allows the bullet to retain its shape and trajectory upon impact with armor, while the softer jacket helps prevent the barrel of the firearm from wearing out too quickly.
AP cartridges are typically used by the military in various firearms, ranging from small arms to larger caliber weapons. However, because of their ability to penetrate through protective barriers, their use is regulated, especially in civilian contexts.