The 7x57 and 303 used on elephant were loaded with armor piercing rounds which today are illegal. Armor piercing rounds are different than solids. There was no "finesse". For plains game a 30-06 is just one of the ideal rounds available in my opinion and that of many better informed.
I'm glad you find humour in the Weatherby and RUM toting guys, it's always nice to have a reason to laugh. You seem to have only seen clowns in camp; I'm glad you found entertainment in the bush. I on the other hand have seen some phenomenal shots using the most powerful Weatherbys and RUMs in the states. From fast accurate very close range snap shooting, including at dangerous game, big and small, to mid range standing unsupported shots to perfectly placed shots at distances I wont even mention. Of course we also have those bar stool prophets who say that a .243 is all they need. It takes all kinds and we're grateful to have them.
Weatherbys and RUMs add punch and extend the range when necessary for those who can shoot them. Like a fast car, they aren't for everyone.
Your statement regarding "armour piercing" ammunition is unfortunately just not true.
https://www.africahunting.com/threads/wdm-bell-his-elephant-hunting-rifles.15057/
“He shot his 1011 elephants with a 7x57mm rifle”...
Bell recorded all of his kills and shots fired. It was a business to him, not pleasure, and he needed to record expenditures…
• He shot exactly 1,011 elephants with a series of 6 Rigby-made 7x57mm (.275 Rigby) rifles with 173 grain military ammo.
• He shot 300 elephants with a Mannlicher-Schoenauer 6.5x54mm carbine using the long 159 grain FMJ bullets.
• He shot 200 pachyderms with the .303 and the 215 grain army bullet.
• He went to a .318 Westley Richards for a while, which is a cartridge firing a 250 grain bullet at about 2400 fps, but found the ammunition unreliable and returned to the 7mm.
• He also recorded that one of the reasons why he favored the 7x57 was that the ammunition was more reliable and he could not recall ever having a fault with it. Whereas British sporting ammunition, apart from the .303 military ammo, gave him endless trouble with splitting cases.( He used the .303 in the hope of running into a Herd of Bulls so he could make use of the 10shots ! He was famed for using a Martini in .303 & holding the spare rounds between his fingers & could fire the rifle as fast as a bolt action !)
• The balance of his elephants were shot with this .318 and his .450/400 Jeffrey double rifle.
• He wrote about being able to drop an elephant with a light caliber rifle if he shot it in the same place that he would have shot it with a heavy rifle.
• It was unmentioned, but understood, that 7x57 ammunition cost a tenth the price of large caliber .450/400 Jeffrey cartridges and money is always a factor in business.
Just out of interest, it is must to be mention that to judge ammunition expenditure and his own shooting, he calculated an average. He discovered that with the .275 (7x57mm) he fired an average of 1.5 shots per kill. This means that half the time he only needed one shot. That is a fair performance for such a large number of elephants killed and considering that it is common today to fire an insurance shot, anyway. Seemingly a business man of a Hunter with a profit & loss acumen.
It is also interesting to note that, although Bell is the most famous proponent of using small caliber "nitro" rifles for large game, he did not discover the technique, nor was he its earliest advocate. Well known hunter Arthur Neumann, for example, had been shooting elephants with a .303 Lee Met ford rifle for years before Walter Bell got into the business.
WDM Bell is forever associated with the John Rigby & Sons Mauser rifle and the .275 Rigby cartridge. ".275 Rigby" was the British designation for the German 7x57mm Mauser cartridge. This cartridge propelled a .284 caliber, 173 grain bullet at around 2300 fps and the bullets he used for elephant brain shots were full metal jacketed solids. He declared once that a soft point bullet had never sullied the bore of his rifle. It is interesting to compare these ballistics with what is commonly regarded as essential performance today.
Weatherby rifles and cartridges are only as good as the shooter. All clients I have guided in Africa who brought Weatherby rifles could unfortunately not handle them.
Even if you can, their excessive muzzle velocity, muzzle blast, recoil and if fitted with a muzzle break heaven help the PH and trackers.
The OP was referring to hunting DG in Africa not Elk in the USA across a canyon! This would be referring to 375 Weatherby, 378 Weatherby, 416 Weatherby and the worst of the lot the 460 Weatherby.
Now when hunting elephant your shot will be typically 10-35 yards and on buffalo 40-100 yards, so what would you need all this extra muzzle velocity for?
Reduced penetration, increased recoil, delayed recovery time for the 2nd shot if needed, inability to place the first shot in the right place due to flinching in anticipation of the shot, closing both your eyes before yanking the trigger and then trying to figure out what happened after you have pulled the trigger! No thank you! I would much rather have a client in camp with a rifle he can handle and shoot well.
If you have as you mentioned seen "I on the other hand have seen some phenomenal shots using the most powerful Weatherbys and RUMs in the states", that is great and I take my hat of to whoever can handle these insane calibers, however I would strongly suggest keeping them in the States, as they have no place in my opinion for hunting DG in Africa, unless you intend shooting your elephant or buffalo at 200 yards plus.
The only sensible thing to do if you are a Weatherby fan is to download them to a velocity that matches the comparative cartridges that have proven themselves over the years for DG hunting in Africa.