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Old December 29, 2019, 08:20 AM   #188
stagpanther
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Join Date: March 2, 2014
Posts: 7,821
Quote:
Truth in lending: The Lil'Gun anomaly occurred using the LEE 358-200 cast at 42ksi indicated -- and measured velocity was waaaay outta whack* to where I couldn't even jigger Lil'Gun's burn parameters to match it at all -- but the incipient failure mode was the same as yours.
One thing about your QL settings--are they set for start pressures for rifle FMJ core bullets? It probably comes up with a default start pressure for pistol bullets (2000 psi or under vs. 6500 psi or more). Adjusting for the start pressure weighting factor, I can get my velocity results within what I'm actually recording on labradar, even though they are well over "published" results. When you adjust that start pressure--you can also see that peak chamber pressure is correspondingly attained much faster. I would love to get my hands on a conventional bolt gun and test the same ammo--but I'm not willing to waste that kind of money on this at this point.

Using a start pressure of 6500 psi for Hodgdon's published load 26.7 max for H110 for a 170 interlock, QL returns a velocity of around 2300 fps--which in fact was what I got when I shot it (interestingly, top velocities were achieved with charges well under that, so I'm assuming a lot of the added pressure is simply being dumped when the case releases and leaks in the chamber). QL also returned a pressure rating of almost 64,000 psi for that load. I believe it.
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Last edited by stagpanther; December 29, 2019 at 08:38 AM.
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