To understand this, you must understand that back in the day if something went wrong it was your fault. Today it is someone else's fault. Enter the lawyers and liability. There was a time, not that long ago in America, where you could by dynamite at the hardware store with no special license (100 or so years ago). Not so much these days, and has been that way for a long time now. You could buy a full automatic Tommy Gun and have it shipped to your door through mail order just like it was a pound of sugar.
If you look at reloading manuals from the 60's or even someone like Elmer Keith or even P.O Ackley, by today's standards that data is way over max. Steel is better today than then and chamber pressure can be much higher than in Keith's day, but liability is much higher today.
Modern bolt action rifles can withstand 100,000 psi. The limiting pressure factor is now the primer in the case. That is your weak link today and there is no way for anyone to quantify, in writing or print, what load that would be in your rifle.
People always say " I follow book recommendation for a given cartridge" that sounds real fuzzy and safe. However if you get your hands on a book from 1950 ( still a published loading) those loads will blow the roof off of today's published loads. Are they safe? Sure, so long as you reduce and determine what is the max in your rifle. Again the liability is on you. Sue all you want but that won't bring back your eyes or fingers. Don't be dumb.
Learn the real signs of pressure. Research it. Test it and find those limits. I'll promise you that they are far beyond current published maximums.