Marco,
The simplest way would be to take advantage of paragraph 4.1.3.1 which states Alternative methods for size evaluation maybe used provided that they can be correlated to to the weight method and are acceptable to the purchaser.
AMS 2430 Table 1 Size uniformity in machines uses sieve analysis for both Cast Shot and Wire. I would use that as your correlation proof. Using AMS 2431/1Table 4 you could develop your own screening requirements based on size. Example 70 cast steel = 12 CCW, 110 = 14, 170 = 20.
This is a heck of a lot easier then measuring shot with a micrometer. I will bring this up at the next SAE / AMEC meeting.
Hope that helps,
-Walter
Marco:
I agree with Walter, however, I would caution you that if you are using your sieves to quality the media as "GOOD or BAD" you should seriously having the sieves that you will use CERTIFIED to either ASTM E-11 or ISO 3310-1. Third party auditors have been known to look for these certifications.
Regards,
Terry
If you are using the sieves often I would also suggest you purchase the stainless steel type over the brass type. As Terry said Certification is a requirement especially if you are Nadcap accredited.