jorge--I have wondered about this too. I suspect that at the higher smokeless velocities the RN solids tend to veer from a straight line and yaw and ultimately tumble, whereas the FN bullets do not. At the lower black powder velocities the RN gives straight line penetration without yaw, hence more penetration. Notice I said SUSPECT, as I have no proof of this, only that the RN bullet is the penetration champ in my Sharps, and always gives straight line penetration in an animal.
