Speer Bullets 38 Caliber (357 Diameter) 158 Grain Jacketed Hollow Point (450Pk)The internal jacket taper of these excellent hollow point bullets limit jacket rollback resulting in better penetration and less chance of a core jacket separation. These bullets are primarily used for self defense or in hunting applications. This is not loaded ammunition. Technical Information Sectional Density: . 177 Ballistic Coefficient: . 158