This OMPC – SS109 – M855 – 5.56×45 Ammo has a jacketed steel core projectile that is designed to punch through light armor and have superior barrier penetration. OMPC “Oman Munition Production Company” is a Middle Eastern ISO certified ammo manufacture that loads their ammo to exact NATO Specs. These specs includes reloadable brass cases, non corrosive boxer primers and powder that will ignite in temperatures ranging from negative 65.2 to 129.2 Degrees Fahrenheit. This OMPC SS109/M855 62GR Ammo ships in a green Military Grade steel ammo can with rubber gasket, Also all the ammo is individual sealed in 20 round boxes, this keeps humidity and contaminants out, so your ammo is ready when you are.