Does anybody have any information on humidity “safe-zones” for storing cartridges in typical flat file drawers at certain humidity levels, or what humidity levels in general are safe for brass cases? I’ve been doing some experimenting over the past year with cartridges left in various places at different humidity levels and have found different results. Some cases (particularly starline brass for some reason) seem to have a sort of rusty corrosion that faintly takes place in as little as 6 months if they are stored adjacent to materials that hold moisture like cardboard, or some foam liners. Sometimes it seems to take place even if they are not stored along with cardboard even. Other cartridges that I have left out in the open on a wooden work bench in my basement for over a year show no such signs of discoloration. When the rusty-colored discoloration does occur it often seems to follow fingerprint marks which were previously not visible on the brass case which leaves me to wonder what chemical reaction concerns might be going on with oils from sweat, etc… These cartridges I have experimented with were various cheap ball rds that were all fairly shiny and new to start with. I have also noticed that nickel-plated brass suffers no such condition issues under any circumstances so far.
Has anybody ever tried to clean such rusty discoloration from brass, and what did you use?
Any other experiences from anybody else with certain drawer liners or cartridge display methods?
What do you guys do for humidity control (absorbing chemical baskets, or moisture absorbers in drawers?)
I had started a couple years ago on setting up all my cartridges for display in drawers, but then backtracked after realizing I needed more space and wanted to experiment with storage conditions for brass / steel preservation since I have a good handful of cartridges with exposed steel as part of the projectile.