Reloader 28: I suspected that the extra freebore was NOT really a non-issue, that it was there specifically to reduce the initial pressure spike and to give the bullet room to build some speed and momentum before it encountered the rifling - that that momentum was one component of the force necessary to swage the bullet into the rifling, thereby reducing or smoothing the pressure component of that force. I've read that the long freebore was an essential part of Roy Weatherby's engineering.
mathman: When I think of repeatedly exceeding a design limit, the stress/strain diagrams from structures classes in college come to mind. Once you exceed that proportional limit, the steel never fully recovers after being stressed. After I left the government, I worked in the specialty metals industry where we cold rolled and work hardened various steels and copper alloys, whereby we purposely and grossly changed the properties of materials by exceeding the proportional limit in a controlled environment.
Then we tested to destruction to verify the desired properties of the finished product. Depending on the material engineering, you could stress cycle a material for dozens, sometimes hundreds or thousands of times before it would fail, sometimes suddenly and catastrophically. I can envision a 7mm Rem Mag digesting 7mm Wby loads maybe a few dozen times, maybe even a couple of hundred times, and the steel in some component of the action slowly becoming work hardened/strained. Then one more round fired is fired and that component fails catastrophically. Most of us have seen horrific photos or heard stories of the destruction that is wreaked and what it looks like.
