My 2 cents worth….
My idea of elk hunting cartridges start with the .260 Rem, 6.5x55, 7x57 - with the caveat that they don’t be used further than 300 yds. Actually, 250 yds would be max, I think. Next would be the 7mm-08, .308 Winchester. They can be stretched out to 350 yds. Now, I know many have said that a .270 isn’t an elk cartridge, but the evidence, otherwise, shows that not to be true. The .270 shoots flatter, and hits harder than a .308, without having the recoil.
Truck loads of elk have been taken with a .270, and it can be used for 400 - 500 yd shots, if need be. Same goes for a .30-06! Except the .30-06 starts to have recoil, and while many men have used the cartridge for hunting, the recoil may be daunting to kids, especially when they just first start shooting, and hunting.
I wouldn’t think of any .300 Mag, or a 7mm Mag. The recoil can be rather stout, and, in my opinion, aren’t starter cartridges.
But, hey, that’s just my opinion!
Hawk