I keep track of the brass being reloaded for the bench-rest rifle. In lots, matching head stamps, number of times it's been loaded. case trim, etc.
I bought new brass for the 44 mag, but am still shooting the original 100 cases I purchased probably 20 yrs. ago. I don't burn through a lot of 44 mag. 38 Spl is a different story.
Ahhhhhhhh, but all this is reload data, not gun data.