Anscheinend greift der Schaumstoff "Zerust" Metalloberflächen nicht an:
"Flambeau provides the ultimate solution in rust and corrosion protection. Zerust is a patented polymer, molded in the plastic, that emits a harmless vapor and forms a protective layer around metal surfaces. All Zerust products will maintain their effectiveness for up to five years so you can count on hassle free, long lasting protection. Look for the Zerust symbol next to those products that feature this revolutionary technology."
Link: http://www.flambeauoutdoors.com/otdrs_hunting/…s/guncases.html