Mr. Howell,
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<br> Thank you for taking the time to respond to my post. You share my opinion on the subject. Here are my thoughts:
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<br> The pressure generated when a case is fired acts in every direction, ie, radially, on the base of the bullet, and against the base of the case and primer. If the pressure exceeds the yield strength of the brass (which is generally the case) the brass will "flow" or "stretch" in every direction till contact is made with the chamber wall (radial expansion) and the bolt face (rearward expansion). At this point the brass is not "containing" or "holding" the pressure as it does not have the strength to do so. Only the bolt face and chamber wall (not the brass) have sufficient strength to contain the force generated by the pressure.
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<br> Therefore, the force, or thrust, applied to the bolt is strictly a function of the pressure and surface area of the bolt face (the area to which the pressure is applied). The shape of the case is not a factor in the equation. If, during expansion, the case happens to make contact with the chamber wall before making contact with the bolt face, the case simply "stretches" rearward till contact is made with the face of the bolt. The full pressure is then acting against the bolt face.
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<br>HogWild
