Nice idea, but too complicated. Spray cans of canola oil, a vacuum packer and the PVC pipe is easier and neater. [Don’t use olive oil spray since it is slightly acidic.] When you open the sealed weapons, plain old rubbing alcohol will clean them right up for oiling and use. Of course this system would only be viable for under fifty year storage ...
“Nice idea, but too complicated.”
Not for us. We’re ranchers so all of the things we needed for our cache were already on the property. FYI the cache is NOT on our property.
(Everyone wave to the nice people from the BATFE!)