I found a Polish PFK Warszawa 1930 small ring rifle which has a rusted out barrel. The action appears to be in very good condition without any rust. It has been years since I worked on a Polish Mauser. I haven't pull the barrel yet.
This is the best machined Mauser that I ever have owned. I believe that these actions are the larger diameter thread 1.100 size. The file test on the action appears to be hard from the heat treatment.

Has anyone had one of these actions swell from firing a modern round like a 243 Win or a 6mm Rem?

less, iirc, those are small ring action, large ring threads..

i wouldn't likely do a 60Kpsi round in one ..

though, of course, you can get a 6rem to go much faster than a 243 (that ought to start some fights)

i have never seen one part due to pressure in that config... so all the savage and 308 and x57 rounds ought to work

7X57, 8X57, 257 Roberts, 308, 30-06 But be sure it's Garand safe. Those would work nice.
I think my next rifle will be a Roberts or a .375 H&H

How about three different levels of cartridge

Purely functional
7-08
260

Pure and Classic
7X57
8X57

Purely Utilitarian
308

Just curious, does anyone know what pressure levels the RWS 8x57 ammo was loaded to? I'm sure plenty of that is shot in smallring 8MM's

Looking through the load listings and Saami specs 7X57 and 8X57 were loaded to about the same pressure 57 Kpsi for the 8mm and 56,500 psi for the 7mm
Which is why I had no fear in chambering a .220 swift in a 1891 with the semi rimmed case head (smaller internal surface area to push on) the bolt trust is reduced to a nominal 55Kpsi

The 257 Roberts looks good to me. Low pressure unless you boast the powder charge to get more FPS out the barrel.

I have searched the web trying to find blown up actions and all I find is one example of a 93 Mauser blown up. I don't think you can compare the 93 to a 1930 SR Mauser made in Poland.
The C ring in this action should add some to the strength.

P.O Ackley blew a few of them up but only with way over board charges.
The Mauser design lends itself to safety
Just don't try to load it hot.