Scott,
How much usage has the ceramic media seen? Your correct that the media will not change size significantly but we're not talking about a significant amount. In my opinion the specifications should be revised to state that in machine media is actually the low end of the tolerance scale. Otherwise you would put brand new media in the machine then have to screen out a significant amount of media to meet the "in machine" requirement. This is not the intent of the AMS-2430. What screens are you using to check new media? If you'd like you can send me a sample and I screen it for you to verify your results.
-Walt
