Kind of blows the old wives tale theory of military brass being thicker and having less capacity than commercial doesn't it?
While I believe you are absolutely correct with regard to 5.56 brass, which is of course the topic of this thread, the general nature of your statement just makes me a little nervous!
Military
7.62 brass IS thicker and DOES have less capacity then commercial brass. I proved this to myself some time ago with many, MANY rounds of various year headstamped, sized, trimmed, weighed and volume measured LC 7.62 brass.
Unfortunately I forget the actual percentages and which brand brass I used as a base. But the difference is significant!
I assume the same is true for 30 cal. brass, but believe me, after doing this little test with 7.62 brass, I had no desire to spend that much time doing it again!