This is my method to get case volume. Please correct me if I am wrong. I weigh a cleaned once fired case ( my rifle chamber ), Then carefully fill the case with water, being careful to avoid any bubbles, then weigh the filled case. The difference is the water volume of the case, which gives me the approximate powder volume. Of course this is adjusted for bullet length. I have found that this is sometimes quite different from the QL estimation. Opinions ?

Once fired case. Resized and trimmed. I weigh the case empty then with water. That is your GROSS volume.

QL will list different manufactureres for some of the cases. YOu will notice the volumes are different. The only CORRECT answer is the one for your brass your chamber and die.

Why is case volume not taken to the shoulder neck junction so that the neck portion is left for the bullet. Surely the difference in seating depth is volumetrically small enough to discount when the usable case volume is taken into account. I am not argueing that some of the WSM's etc dont have bullet intruding into the usable case volume but to take the volume of the neck into account seems counter productive to me.

Just an observation on my part.

Von Gruff.

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Why is case volume not taken to the shoulder neck junction so that the neck portion is left for the bullet.

Simply easier to measure a full case than TRY and measure to the same point in the neck two times in a row.

Programs like QL take the gross and calculate the net depending on OAL. Pretty easy to hand calculate net on flat based bullets.

I agree the net capacity is what gets the work done.

quote:

Originally posted by ramrod340:
Once fired case. Resized and trimmed. I weigh the case empty then with water. That is your GROSS volume.

QL requires the volume of the fired case. Sizing the case prior to taking the measurement will falsify your result.

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QL requires the volume of the fired case. Sizing the case prior to taking the measurement will falsify your result.

Well CRAP!!!!! I guess it took the third reading to finally read page 63 correctly. I had built all my wildcats into the system using resized capacity. Now I have to go back and change them. But DArn the smaller case data match so darn close to actual results.

Anyway thanks for helping this old guy correct his mistake.

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Originally posted by McFox:

quote:

Originally posted by ramrod340:
Once fired case. Resized and trimmed. I weigh the case empty then with water. That is your GROSS volume.

QL requires the volume of the fired case. Sizing the case prior to taking the measurement will falsify your result.

Correct, use a fired case.

quote:

Originally posted by ramrod340:
...But DArn the smaller case data match so darn close to actual results. ..

Then leave it alone. Software Models have to be "approximations" because of all the Variables in the Chambers, Bores and Lot-to-Lot Variations in the Cartridge Components. Most of the Software requires "Fudge Factoring" to match-up closely with Reality - apparently you got close enough the way you did it.

Best of luck to you.