This is .223 Winchester Super Short Magnum (WSSM) Winchester Supreme 55gr. Ballistic Silvertip Ammo. This ammo has many features including a copper jacket with uniform sidewall thickness combined with a solid base boat-tail for maximum accuracy and a Lubalox (Black Oxide) coating to reduce barrel fouling. Other features are a polycarbonate tip to resist deformation and aid in rapid expansion. This ammo comes packed in 20rds. per box.