Pressure will not crack stocks, but excessive pounding will, especially if the wood is old, brittle, oil soaked, or all of the above.
Pressure will exert more force upon bolting surfaces, hinge joints, and the receiver itself. Barrels in good condition will usually take a surprising amount of pressure before they fail, but one failure can end your shooting career in a split second.
Turn of the century guns were built of milder steels with less refined metallurgy, alloying, and quality control than is common today. They were built to handle the loads in common use at the time. Most importantly, some action designs are better able to handle a multitude of shots at maximun design pressure before they wear or break. If we could find a new in box N. R. Davis and a new in box Winchester model 21 and began firing the same 12 ga. RST low pressure loads in them, most everyone here would bet large money that the Model 21 would still be tight and sound when the Davis was worn out. Jump up to standard pressure loads, and the Winchester will hardly hiccup while the Davis will slowly be pounded to death. Once the wear starts and bolting surfaces are peened and deformed and the gun gets loose, the rate of additional damage will accelerate. Certain designs are just better than others. Cheap guns of poor design and materials just don't stand the test of time unless they spend most of that time sitting in a closet unfired.
If your Davis was properly put back on face and you use conservative loads in it for hunting, it will probably outlast you.
