The cartridge is of partially synthetic material, partly metal construction and of conventional bottlenecked form. The projectile is a fin-stabilised 35 grain, 5.56mm tungsten carbide or depleted uranium penetrator dart with an effective range of 1,000 to 2,000 meters depending upon the nature of the target. At 800 meter range, the dart will penetrate 40mm of Rolled Homogeneous Armour (RHA), with considerable secondary fragmentation behind the plate. The high velocity produces an exceptionally flat trajectory. The vertex at 1,000 meter range is only 800mm above the line of sight. The cartridge uses a long primer to give optimum ignition of the propelling charge, and a pusher plate drives the projectile up the bore.
Early in development, Steyr Mannlicher started with 12.7mm and 15mm caliber rounds, before transitioning to the 14.5mm APFSDS with the AMR 5075 prototypes. When the AMR 5075 did not get adopted despite significant interest in the weapon, and the weapon was refined further in the form of the IWS 2000, the caliber was changed to 15.2×169mm APFSDS.