Quote:
Originally Posted by Gary Laudermilch
I have no desire to load and shoot a load in excess of 1200 fps preferring something under. Because I trusted published data I never saw a need to test. That assumption may or may not be correct. In fact we do not know this test data reflects what goes on in a typical barrel. To that, note the bore diameter of the test barrel of .614, That is a bit tighter than a typical 20, at least the one's I own which are closer to .618. Not much difference but how much does it take to uptick pressures?
I do plan on submitting additional losds for testing and included will be my base load with a Win primer.
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Gary, My Briley 20 ga tubes are 0.618 also and I agree that the test barrel 0.614 seems tight. The volumetric difference between the two bores is only about 1.3% which doesn't seem significant. What I wonder is how did Hodgdon measure the pressures of therir published reloads? How does their pressure test equpiment differ from what Precision is using to measure pressures? Your tests of identical WSF 20g loads except one used CX2000 and the other used W209 primers showed that there was about 440 psi difference in average pressure with the CX2000 being the hotter primer. The big question for me is how are the powder suppliers measuring pressures of their published recipes and how does it differ from how Precision does it?