I have several handguns/mags for which I have no immediate need. I have stored these in plastic ammo cans with a rubber seal. They were well oiled and placed in the cans with a large amount (about 8 oz) of silica desiccant powder. The silica is in a small plastic container (with holes drilled in the lid) inside the ammo can.

A quick check of Amazon shows oxygen absorbers from 100cc up to 3000cc. I have no experience with oxtgen absorbers. Would they be better than silica, or possibly in addition to? Any suggestions?