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Ghost101
10-13-2013, 06:13 AM
How can I figure out chamber pressures? Can it be done with a chronograph ? It seems that I have read it somewhere on here or a link from here, but can't seem to find it as most of my notes have been moved into a storage unit.

Ghost101

runfiverun
10-13-2013, 11:40 AM
pressure is related to velocity but not really in a linear way.
you can over pressure a load and flatline velocity or even lose velocity and have pressure keep on climbing.
you can use a chrono and measure che and compare it to a baseline pressure tested load but this gives you a one time measurement on a case and the cases should come from the same lot of brass.

the best way would be to use pressure trace equipment and a transducer set-up.

Larry Gibson
10-13-2013, 03:21 PM
You can "compute" it with Quickload or the old Powley computer (slide rule) but there is no way to actually measure pressure using a chronograph. However, with proven data from reliable source the chronograph can give a comparative idea about how close you are to the pressure level of that data IF you are using the same components.

None of the above or using CHE or CRE are reliable as a measurement of psi.

Larry Gibson

Ghost101
10-14-2013, 03:37 AM
I don't know if "Quikload" will work on my Mac, but will be finding out. The "Powley Computer" I believe was designed to only work with, I think, IMR powders.

This week is going to be dedicated to building a powder magazine on wheels and also one for primers. Steel outer and wood with slider inside. CA you know.


Thank you for the info

Ghost101

JakeBlanton
10-14-2013, 04:51 AM
You'll probably need to get a *real* computer, not a Mac.

Here's a writeup by someone who did the same thing:

http://www.ktgunsmith.com/straingauge.htm

The software runs on a PC.