The Steyr IWS 2000 is an Austrian single-shot bolt-action anti-materiel rifle produced by Steyr Mannlicher. IWS stands for Infantry Weapon System. Like many anti-tank rifles, it is actually a smoothbore weapon and not a true rifle. This can help accelerate projectiles and increase ballistic effectiveness, but the lack of rifling imparting inertial stability requires the projectile to have stabilizing fins. It fires a 15.2×169 mm armor-piercing fin-stabilized discarding-sabot round (207 mm long), and is the first man-portable rifle to use this type of ammunition.