Armor-piercing refers to ammunition designed to penetrate armor or protective barriers. This type of ammunition typically features a hardened core made from materials like tungsten or steel, allowing it to effectively breach the protective layers of vehicles or body armor. The effectiveness of armor-piercing rounds is often measured by their ability to defeat specific levels of protection, such as those found in military vehicles or personal protective equipment. These rounds are commonly used in military and law enforcement applications, where overcoming armor is crucial for mission success.