"High penetration rounds, effective against vehicles and infantry armor."
— In-game description
Armor-Piercing is a weapon attachment featured in Call of Duty: Ghosts. It functions similarly to FMJ from previous titles, but now also boosts effectiveness against armored infantry (Ballistic Vests and Juggernaut Armor) as well as destroyable enemy killstreak rewards such as SAT COMs, Sentry Guns, and Battle Hinds. It is also an ammo type in Extinction. The CBJ-MS submachine gun comes with this attachment integrated, and thus it can be paired with another Mod attachment (unlike with other weapons). Despite menu stat bars, this attachment doesn't actually directly increase the damage of a weapon. It does, however, increase the damage done to killstreaks and Juggernauts. It also completely ignores the effects of Ballistic Vests, allowing normal damage to be done to players wearing them. The damage done by shooting through materials is increased as well, although bullets will still be less effective through walls compared to directly hitting enemies. It is the most recommended for use with LMGs due to their already high penetration. A player can kill enemies through walls with decent effectiveness using this combination.