All of the 2000 and later Estes motors that I have used have had the letter 'A' at the beginning of the date, except for one pack of B4-2s with the code of 'B020201'. Your assumption about the numeric part of the date code is correct. Some of the more popular motor types (i.e A8-3, B4-4, B6-4, C6-5, etc.) made in 2011 or later may have one extra digit at the right end of the code.

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'Til next time,

Mike Toelle

NAR 31692 L1

SAM 0373