How to measure case capacity?

[okksu]

Mixed bags of brass for several of my milsurp rifles (as in what brand was on sale for cases I needed at the moment?) So: What is the best way to measure case capacity? 2. At what % point does the difference in case capacity become significant to down range results? Or, is this a wasted exercise for my 100 yard bench milsurp shooting?

[Dannix]

iirc - water and 70%.

Somewhere, can't seem to find a link right now, there was a good article where the author gos to great lengths to see how accurate he can shoot his 30-30. Could be a good read for you...if I could find it.


Edit: Ah, here it is: Optimum Accuracy with Cast Bullets in a 30-30 Winchester Model 94 (http://www.castbullet.com/shooting/accu.htm)

the cast bullet "experts" say you need at least 75% loading density for target grade accuracy

The before, for comparison. (http://www.castbullet.com/shooting/3030.htm)

[okksu]

Dannix, Thank you for the article. Pretty much what I was looking for.

[Echo]

I seat a bullet in a de-primed un-sized case, weigh it, then use a hypodermic needle to squirt H2O in through the primer hole/ When full, I weigh it, and the difference is the weight of the H2O, that can be converted however one wishes. The Powley Computer used H2O weight, I believe.

[mike in co]

I seat a bullet in a de-primed un-sized case, weigh it, then use a hypodermic needle to squirt H2O in through the primer hole/ When full, I weigh it, and the difference is the weight of the H2O, that can be converted however one wishes. The Powley Computer used H2O weight, I believe.

but that is only the volume/weight of that seating combination.

( my software adjust vol based on seating depth)

i use full case capacity with 77 degree water.......1 gr = 1cc

i seat a spent primer backwards, weigh,fill with water, tap, try for a flat miniscus , weigh again, the diff in gr is cc's if one uses water at 77degrees(25C).
i use q tips to get the level correct.

mike in co