Not arguing just trying to learn. Seams to me that bolt thrust will be the same weather the entire case moves back.Or just the head do to stretching at the web juncture.
Not contradictory at all. In both cases, bolt thrust was significant. When dry, the case separates ahead of the web. If oiled, the case moves back and the shoulder moves ahead. Only the springiness of the Lee Enfield makes this obsevable. If the chamber is polished real well but the case is dry, the case still separates.
I did a lot of testing using a Lee Enfield to try and get a feel for the advantage of the "improved" case for reducing bolt thrust but could not see any evidence for that either.
Grip is grip. Once the case grips the chamber walls sufficiently to separate the case, gripping it more means nothing. The only thing which seems to eliminate adhesion to the chamber wall is lubrication. GD
Force against the bolt face will be equal to PSI X case head area either way. Force against the bolt face may be less if the case separates, and some of the pressure is vented.
