Sterling M193 556NATO 55 Grain Full Metal Jacket 30 Round Box. S. A. so you can enjoy copious amounts of target practice without having to invest in brass This ammo's not reloadable" although it is corrosion-free thanks to its modern non-hygroscopic primers. Specifications for Sterling M193 556NATO 55 Grain Full Metal Jacket 30 Round Box: Manufacturer: Sterling Caliber: 5.56x45mm NATO Number of Rounds: 30 Bullet Type: Full Metal Jacket (FMJ) Bullet Weight: 55 grain Features of Sterling M193 556NATO 55 Grain Full Metal Jacket 30 Round Box: 5.56 NATO Package Contents: Sterling M193 556NATO 55 Grain Full Metal Jacket 30 Round Box