I just print a simple lot number on my boxes/bags of ammo. I hand write the actual information in a reloading log book. The lot number is based on a simple date stamp, automatically generated by my 15.00 electronic label maker.
The label goes in the trash at the end of the day. The log is more permanent and is helpful for tracking down all potentially affected lots, if a problem is discovered.
I do the same for lots of brass in various stages of prep. And for home cast bullets. So an entry for finished ammo might include the quantity in that lot, amount/type powder, how it was measured (dipper or measure; if measure, which insert was used), OAL range, and the lot numbers of the cast bullets used and of the primed and prepped brass, for instance. And somewhere further back in the log, the info for the specific lot#'s of bullets and brass has already been recorded, chronologically. The info for the brass could include what expander was used and what brand/type/lot# of primers and quantity of pieces, and it could include any additional sorting or processing I did. The info for the cast bullet could include quantity, alloy lot number, lube and sizing info, air vs water-cooled etc. There might also be a note that I had to clean and lap the top of the mold before that session; therefore, the previous lot of bullets from the same mold might be expected to not be as uniform. And the alloy lot number might include some info for that lot of alloy.
Whenever I open a new lot number of powder or primers, it is also recorded chronologically, so even if I don't record those every time, I can see which lots are before or after. I just have to record it at least the first time I use a new lot of primers/powder.
It's a lot of info. Keeping a chronological log means I only have to record this information once. It has come in handy. I recently found one of my regular standby loads had grown slighty too long to easily chamber. This had never happened before; I mean, I guess I never knew exactly how long was too long. But I could track back to the last time I changed the seating die and I was able to identify and fix all the affected lots of ammo. For the future, I know pretty much exactly the maximum this bullet can be seated before it is a problem, if I refer to my log.
