Hi Dave and Walter.
These old Glass bead sizes can be a real pain at times.
You may well have solved this problem, but if not, you may want to try Hodge Clemco as my contact (James.Frost@hodgeclemco.co.uk) tells me they can supply all AGB- sizes to meet AMS2431/6.
The typical Silicon content is 73% and never less than 67% so that all looks good. Contact details: James.Frost@hodgeclemco.co.uk
I can't imagine the varying sample size will be an issue as it's the percentages of those samples that are critical values.
Hope this helps.
Very Old Tom
