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Paul Leverman

I've never really concerned myself over this. Apparently, it can give an indication of what could or might be expected for the performance of the loaded cartridge.

I did some google-ing to see if there was any worthwhile information out there. What I got back just confused the hell out of me, so now I turn to all of you to straighten out what's left of my mind.

The scenario is this: I had three cases on the bench. A .308Win, a 7X57 . and a 30-'06. Interesting brothers from the same mother. On a whim, I necked the 7mm up to .308 to see what it would look like. Surprisingly it looked like it should have been a 30 cal all along. Another errant neuron connection got me to wondering how the case volumes related to each other. After I got my numbers, I hit the google button to see if I was on track.

This is where it all went south. I found sources that said the 7X57AI had less capacity than it's original form. Another source said the 308W and the 7mm were within 1.3 gr of water. None of this made sense. How could a case that is considerably smaller have almost identical internal capacity? Maybe really thick brass in the 7mm? Then there's the case where you take the taper out, blow the shoulder angle forward and lessen the capacity.

Am I being stunned here, or what? This is not what I found in my measurements at all.

If anyone out there is willing, could you post the water capacity of your 7X57, and if you have one, of your AI. Please don't use "net" information, I'm after real, physical measurements.

Thanks for any help in this.


Ironically, the anti-spam characters for this post are "psi"