An Austrian single-shot bolt actionanti-materiel rifle produced by Steyr Mannlicher, designed in mid-1980s. IWS stands for Infantry Weapon System. Like many anti-tank rifles, it is actually a smoothbore weapon. 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 is chambered in a 15.2×169 mm armor-piercing fin-stabilized discarding-sabot cartridge, and is the first man-portable rifle to use this type of ammunition.
