Military brass isn't always thicker than civvy brass, although it's a common misconception, and you hear it a lot.
Don't believe everything you hear on the Internet, it's easy to measure yourself: Weight it, and compare it to a piece of commercial brass. Fill it to the neck with a fine ball powder, and then weight the charge, and compare the two.
Lake City '06 5.56 brass is a good example of this. It actually has a HIGHER capacity than commercial Winchester and RP brass.
In any case, it's *always* a good policy to drop your loads a few percent and re-working them up any time you change any component.