Federal Premium Vital-Shok 357 Magnum Ammo 140 Grain Barnes Expander ammo review offers the following information; Premium V-Shok ammunition is useful for everything from plinking to varmint or small-game hunting. Each round provides the shooter explosive disruption so it’s perfect for competition or an afternoon on the prairie. Nosler’s Ballistic Tip Varmint Bullets are designed for violent expansion upon impact. The bullet is tipped with a polycarbonate tip which rapidly drives back forcing the thin jacket to expand and fragment. The heavy base prevents deformation during firing and the boat-tail design increases the ballistic efficiency of the bullet. This ammunition is new production and non-corrosive.