There are a few US military FMs(field manuals) or TMs(training manuals) meant for SOCOM(spec ops or Rangers, SEALs, SWCC, ParaRescue, SF, etc). These operators & commandos are trained to hide or "cache" weapons & supplies(food water ammo etc).
Some online sources for military FMs(the newer web or CD Rom types) include: www.deltapress.com www.paladin-press.com www.uscav.com www.actiongear.com www.gunvideo.com
Top CLPs good for long term storage include Eezox, LPX, Gunzilla & the museum grade Breakfree.
& MidwayUSA.com are good sources.
www.gunzilla.us www.weaponshield.com www.eezox.com www.nra.org