Years ago I used to scrounge brass out in the desert around El Paso. I think some of it may have been on the ground ten years or more. Much of it was for rounds o did d not reload at the time, but some of it I used. It seems I latched onto a lot of very brittle brass, but I could not say for sure the bad brass was the really old and tarnished stuff I picked up, but I always suspected that it was. So, I think that using brass that may have been on the ground for a long time might not be a very good idea.
God I am hating caliber threads more and more