 The bullet has a sectional density of 0.287 which is similar to that of a .308 caliber (7.62 mm) bullet.The bullet which has a sectional density of 0.328 is similar in sectional density to a .308 caliber (7.62 mm) bullet.As sectional density plays a large factor in penetration, the .264 caliber (6.5 mm), though a diminutive caliber from a North American point of view, has had excellent results in the field.