Quote Originally Posted by ireload2 View Post
The case pressure ring material has to stretch radially until it it constrained by the chamber. There is some bending since the stretch occurs at an angle due to the proximity of the solid head. However this still results in the pressure ring being stretched buy the difference in diameter of the case and the chamber as well as the forces that stretch the case along it's longitudinal axis. Stretch along the relatively long longitudinal axis has the opportunity to get spread over a long portion of the case length. The radial stretch that occurs to the pressure ring area is concentrated over a short distance increasing it's damage to the case wall. If there was no stretching caused by the difference in diameters it would be possible to use a much smaller cases head with no consequences. We know that is not possible.
If this were true, we'd expect cases to separate at the junction of solid web and hollow body. However, they don't. They chop at some distance from obvious point where the body has expanded to meet the chamber. Nice theory, but the physical evidence seen in a typical separated case just doesn't seem to support it.