Slamfire won't agree that there is such a thing as a "good" '98 Mauser.
But when you get into the "modern" guns from Remington and Winchester, the concept applies.
But the problem is, how do you know when you are there? There is no published pressure tested data for full power .257. Roberts shooters are hamstrung by the notions of 1934 or are dependent on rule of thumb or calculated loading.
World War 1 era and earlier M92's, M96's, M98's were built for cartridges in which the maximum pressures were 43,000 psia. By the time you get to WW2 the maximum pressure of the 8 X 57 mm is 46,000 psia. Maybe the metallurgy improved, but there were still millions of older GEW 98 rifles in inventory, many of which were converted to K98 configurations.
These older actions were made out of plain carbon steels, and when you look at metallurgical analysis of period metals (I found a couple of metallurgical analyses of 19th century bridges), the same equivalent steel today is much cleaner, and stronger. That old stuff always has more slag and impurities which makes the steel weaker.
Now, you put the 257 Roberts in a rifle made out of a modern 4140 alloy, such as my pre 64 M70 Winchester
than your safe pressure limits are the same as any other modern rifle action made out of modern alloy steels. This rifle also has a long throated chamber, so I was able to seat the bullet out about two tenths of inch further than factory. I think this is just great and, it allows me to pack more powder in the case. I have no idea what pressures I am running, but the thing feeds and extracts reliably.
If you plan to use a vintage action understand the limitations of the things. The manufacturer did not anticipate or plan for you to be using that rifle long after the demise of the factory and after the funerals of all the people who made that rifle. You can rest assured that the manufacturer did not use a better grade of steel than needed, nor was the heat treatment altered, to make the surface harder, just in case some one wanted to use a 60 kpsia cartridge. These are things you can bet on. If you are going to use military actions for cartridges whose operating pressures are above the proof pressures of the original action, you need to be cautious. You should always wear your shooting glasses. You blow a case head, due to receiver seat set back, shooting glasses might save your eyeballs. No guarantee, but they might.
I found this an interesting post on the M1917 action:
Thoughts on my sporterized Springfield M1903?
https://thefiringline.com/forums/showthread.php?p=6546703#post6546703
I've experienced a catastrophic receiver failure. I will tell you flat out it's NOT something you EVER want to happen.
Over 100 stitches in my face/neck, shattered jaw that was wired shut for 12 weeks, a hole in my neck to breath through, weeks of missed work, weeks of being fed through a straw, lost 20-25% of my body weight, permanent nerve and tissue damage resembling the effects of a light stroke.
Hop right on that train Dude cause my seat is empty.
One of the "glass hard" P17 actions re-barreled to a belted magnum. Those actions are some of the strongest known (sarcasm). Some of the "over treated" ones are really strong right up to the point when they grenade.
You should always check to see if either the lugs or the receiver seats are deforming. If they are, take the receiver off the barrel and throw it into a trash can.
You can do whatever you want with your action, but I think it is prudent not to use cartridges of higher pressure than for what the action was built and issued. The older you get, the more you realize, permanent injuries don't go away, and the human body does not have redundant parts. Pay $250,000 to $500,000 or so in medical costs, because some $300 antique blew up in your face, and you won't think that rifle was such a great deal.
