I know it may be mixing apples and oranges, but my two lots of ADG .308 Win brass have walls that are 0.014" thick. So I was wondering how you measured yours? Calipers tend to have poor precision measuring the ID of small holes due to the small flats on the inside of the jaws (see illustration below). Getting a number that is low by one or two-thousandths is pretty common measuring holes in the bullet diameter range. A big diameter hole or the distance between two pins or flats is what those ID jaws do better. I either use a pin gauge on the inside of a case or use a small hole gauge for a transfer measurement to an OD thimble micrometer or just measure the OD of a bullet and seat it and measure the OD of the neck over top of it and divide the difference by two, as I described before.