An anti-tank rifle is a type of firearm designed to penetrate through armor, most notably tank armor. Its usefulness ran from World War I up to the Korean War. Though modern medium and heavy tank armor are too thick to be penetrated by small arms fire, anti-tank rifles are still deployed against other targets. Anti-materiel rifles of today, such as the Barrett M82, are a development of the Second World War technology.
The tug of war between armor and projectiles had been developing for a long time; it was not until soldiers met armored vehicles that a conflict between firearms and armor began. The introduction of armored vehicles led to the development of the first anti-tank rifles.