mauser 8mm post
at 400 yard a .243 drops about 20" and is barely packing 1000 ft.lb of energy. I consider it just barely a deer cartridge at that range....ok for small deer but not a big Iowa buck.
The 30'06 drops about the same but is still packing almost 1700 ft lb of energy. Still elk medicine and plenty for any deer that roams the woods.