Filling for de-activated rounds


I have some steel and some brass rounds that to preserve I am going to remove powder and clean primer using the method described in an earlier thread by Doc AV.
My question is, does tumbler medium that I believe to be ceramic have corrosive properties, as I have a suitable quantity for the thirty or so rounds I have identified as worth going to the trouble to preserve.
The ceramic is small in size and would be a good substitute for the removed powder to retain the weight when the projectile is reseated provided it will not react in some way with steel or brass.


Terry–It should be OK. Most ceramic materiels are inert.
Another safe subsituate is dry beach sand. Aquarium filler used in fish tanks also works well.