The greatest difference is in bullet development.
Larger belted magnums became a thing because 303, .270 and 30/06 factory ammo was inconsistent and loaded down.
Handloading was just for a few of the gun nuts and Nosler Partition was expensive and less accurate than the plain old Sierra, Speer and Hornady stuff. I was handloading at this time.
Many of my friends moved into the larger chamberings because bullets failed, the larger left larger residual pieces of bullet in and around the vitals.
These days are quite different, bullets can be extraordinary and super reliable.
I suppose local conditions and tactics might influence things but here on the west slope of the Rockies a .270- .280- 30/06 is ideal , in a light , short and easy to carry version. Enjoy your Sunday
