I am one of those nuts running after every date on the headstamp for every round.
Looking at my tinned fluted 30-06 Dummies from Frankford Arsenal, I see following variations
the first and last dates I have for these are:
#1 4 holes in lower part of case (re-worked 30-03 dummy)
earliest FA 5-03 latest FA 10-04
#2 3 holes in middle part of case
earliest FA 1-05 latest FA 36
#3 one hole in middle part of case
earliest FA 18 latest FA 39 / FA 39 NM
#4 without holes
earliest FA 28 latest FA 41
Does anybody have any earlier/later Dates for any of these ?