Keep in mind that while the ought six is and always will be the standard against which others will be judged, it is one hundred and four years old.
Today, in this era, Old is ancient history and has little value. Old is passe, new is great, better in every way. So are the older calibers looked down upon, is there any value in the short magnums over the older ones. Perhaps, but whatever that bullet strikes, doesn't care. Lets face it, new cartridges sell new guns, new reloading equipment, powder , bullets. If we only bought what we needed, how boring life would become. If it be known, there has been very little advancement since the 1900's when countries engaged in Colonialism, England, Germany and several countries needed new calibers, "dangerous game cartridges" They also needed small calibers for the light skinned game in Africa large for dangerous in India. If there are doubters, Pick up a copy of Cartridges of the World and compare them to what we have today. The names are strange, but the velocities and power are very close.
The main difference has been in the advancement of powders making higher velocities out of less volume cases.
I would not be too concerned about the power necessary at 500 yards as extremely few shots would or should be taken. 200, okay. IMHO only.