To apply the best of modern reloading techniques to one cartridge and then compare it to published data on cartridges loaded nearly a century ago isn't valid.

To load a cartridge to pressure levels acceptable only in strong actions made of the best modern alloys and then compare it to cartridges loaded to be safe in actions using 19th century metallurgy isn't valid.

Try chambering one of your +P .458 winmags in a circa.1900s double and see what happens.

Until you're shooting identical projectiles at identical pressures, you're not comparing cartridges but actions, powders and projectiles ..... which isn't exactly scientific.

I alswo belong to the group which believes that people who short-stroke a magnum-length action have a 90% probability of short-stroking a standard length action.
Working at that speed and under that level of motivation, one doesn't regulate the length of stroke so neatly that it makes a difference. One either cycles it fully to hit the bolt-stop, or one doesn't.

Regards.......... Peter