Hogwild, I don't know. I've been re-reading Mr. Bromel's introduction to interior ballistics, and I can't seem to "make all the pieces fit".
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<br>I happen to have a falling block that is quite sensitive to bolt thrust. Using Quickload to estimate pressures, I run into a noticeably harder dropping block at about 45,000 psi with Varget or slower powders, but I can get to 55,000 PSI with 3031 or H322, as long as I use a light bullet.
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<br>So, in light of that, I conclude that bolt thrust has a time component, somewhere. It may just be that the steel in the action needs time to move. Whatever the second component is, peak pressure is only part of the answer. I would suspect that Ackley's model '94 experiment would come out differently with slow burning powders, but I'm not the experimenter that's going to find out in this case..... FWIW, Dutch.
