not that i'd make too much difference behind the ear. But if it actually has to penatrate the skull it makes quite a bit of difference if that's a 160gr RNFP at 850fps or a 250gr SWC at 850 fps.Let's me go another direction: will a .44 special at 850 fps hitting a 150-200 hog behind the ear at at 50-100 yards make it DRT? Assuming a hard cast bullet.