Most KEKV (Kinetic Energy Kill Vehicles) designs are intended to be made of tungsten and are narrow rods around 0.3m across. If you looked up the "**** Space Program" recreation (were he built in RSS with full realism the entirety of the Aggregate series from the A-4 to the A-12), you would see that V2s regularly hit the ground at speeds well over mach 4, at least using FAR and Deadly Reentry to simulate it. Keep in mind that V2s were not made from tungsten, and had much more area to generate drag. EDIT: Apparently the name of the political party that lead Germany through WW2 is censored on this site.