Re: Spam Can Ammo Caches

A large cache raided overseas.

From today’s letter to Survivalblog concerning caches…

A reader dug his up to inspect the conditions and commented on how well the Russian spam cans held up. The pictures tell the tale. cache1


The author indicated that he buried the spam cans in 2009. That gave them five years underground. They’re not looking too good. For that reason I felt it pretty prudent to post this, since I know many in the audience at a minimum has some ammo cached somewhere (among other essential items…right???)  and the experience needs to be shared.

I’m not picking on you (seriously), but this is not how you cache anything. Spam cans are great for shipping ammo and keeping it all in one place for a long period of time, but when exposed to water some problems pop up. Metal does what when exposed to water…rusts…right? Dirt does what over time…holds water right? Right? So while the green paint does a bit to mitigate the rust, it’s not going to stop it. In five years’ time he has a spam can that now is dangerous, because while it may not appear to be punctured, water still may have gotten in, which may have damaged your primers. Hopefully it didn’t.

Anytime you stick any metal in the ground, at a minimum wrap it in a plastic contractor’s trash bag (they’re very thick and generally much stronger than household bags) or spray it down with POR-15 (an extreme anti-rust primer…expensive but worth it) before sticking it in the plastic. If at all possible, take it out of the spam cans and put it in something more creative that doesn’t scream,”I’M AMMO!!!!”, along with a few other useful items that you’ll need if you’re digging up ammo (like the weapons themselves, maybe some kit and magazines to carry the ammo, maybe some spare tools, maybe some antenna kits…just a thought) Attached is the Army Special Forces Cache Guide for you to download. Read it over.



34 thoughts on “Re: Spam Can Ammo Caches

  1. Matt

    If you’e gonna put something into an ammo can for long term storage, I’d recommend putting ZCORR bags into them first. The bags are perfectly sized for 30 & 50 caliber ammo cans, seal, and are waterproof. Plus the insides of the bags off-gas a vapor that they claim reduces the potential for corrosion. Their bags are used for long term rifle storage. You can find them at:

    I’m not associated with them, but do feel that they provide increased protection for items stored in the cans.


    1. JTwig

      I’ve wondered how well those would work, especially if combined with the PVC pipe describe in another comment. I’ve bought a few, but have yet to even open the package on them.

      1. They work fine for their intended purpose- organization within an already established cache.

        I like them a lot personally, as do many, many others. In dry conditions overseas, they’ve been known to last generations. We recovered several that were buried from the old Muj days in Afghanistan.

  2. We use 6″ PVC pipe sections with adaptors for screw on end caps primered and glued to them.
    The “canisters” are lined with a rust inhibiting paper that machine and tool and die shops use to ship parts/tools wrapped in.
    The ammo goes in,the end caps are screwed on hand tight,then we run a bead of silicone caulk-the outdoor grade stuff-around the caps where they’re threaded on.
    We dug a few up that were buried in summer of ’08 this past summer-had some 5.56,some 7.62×51,and one with Triple7 pellets and loose powder,along with 209 primers and percussion caps plus round balls,patches,bullets and sabots,
    and a tube of Bore Butter in them.
    Everything shot fine-no issues.

      1. Nice…I’m gonna check that out.

        I’ve used POR 15 on 80s K-series Chevy rust- anyone who’s owned one immediately knows what I’m talking about.

  3. Mike Hohmann

    I’d double/triple bag the ammo cans w/ heavy garbage/leaf bags, and double knot/tape each bag, and maybe put them in plastic storage containers caulked tight w/silicon sealer, before burying. Put 6″ of sand in bottom of hole, with good sloped surface drainage on top. You might want to preserve the ammo cans as well as the ammo. Plastic cans could be an option, but structurally weaker than steel. Also include additional storage bags, just in case you need to re-bury anything later.

  4. Keypounder

    I have seen 30,50, and 20 mm cans dipped in asphalt waterproofing hold up extremely well. Not for frequent openings and closings, but to resist long term storage in damp ground that is hard to beat. PVC containers are also good, but size limited.

    One advantage of PVC and other Heavy duty plastics is that they reduce the signature for metal detection. Also, using end caps rather than screw fittings reduces cost and makes a more scure seal; instead of cementing the cap on, seal with marine bearing grease onthe pipe, and slide the cap on.

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  6. Ratchet

    Major von Dach in Total Resistance has some specifics on caching. He has drainage in the hole and no dirt in contact with the cached item. Other details in the book.

    1. One reason to avoid soil contact is to keep steel-to-moisture contact down. In the context of having steel in contact with moist soil, this also reduces the metal detection footprint as well.

      On that note, if you have detailed location information and are not planning on using metal detectors to find the cache, a good use for scrap steel, especially old wire fences, is to bury them about 6″ down in random locations, both close to the cache and farther away. Probably the best use for old nails is to get them roughly straight and use a carpenter’s pea-shooter to insert the nails into the ground. You can deliver hundreds of old nails into a 25′ x 25′ area in a hurry. Scrap rebar a couple of feet long driven a foot or so down in random locations within that 25′ x 25′ area will simulate a buried rifle; put about 10 of those into each area. This will drive anybody trying to use metal detectors nuts.

      If you do about a dozen or so areas like this in the general area of where you are planning a cache, especially on the approaches to the cache area, this will be a powerful dis-incentive for anyone trying to metal detect and steal your cache, whether they are official or free-lance socialists.

      Truly devious people will plant a motion sensor alarm with a radio transceiver to alert them to digging in the area, which will allow a response……..

      Probably the best thing I have seen for buried caches are food-grade PE barrels with removable tops. Food processing plants routinely sell these in sizes from 20 to 60 gallons for just a few dollars, and they are the nads for cache-making, especially if you are planning to store bulky non-metallic things like clothes, boots, and plastic packed food. These are virtually undetectable by anything but GPR. 1 to 6 gallon PE buckets are available in my area free for the asking from the local grocery store bakeries, too, for smaller sized items. I spray paint them OD before using.

      Don’t forget a few cloth tarps to catch the soil as you dig. My wife bought a bunch of very heavy cloth commercial table cloth covers for a buck apiece at a church yardsale which work very well for this. Plastic tends not to hold up under prolonged shoveling. Why more than one? Because the soil has layers, each of which is a different color. Topsoil is usually darker in color than the subsoil layers. Make sure that you match the color as you replace each layer, and don’t bury leaves as you back-fill. These are all ‘tells’ to the educated eye.

      Good luck, one and all!

  7. Don’t overlook using buried pond liner cut to purpose to make an “umbrella” over your cache. It blocks surface water penetration, and gives you an underground roof over the cache site. You can cut bigger pieces from large ones to purpose-fit.

  8. brunop

    If you are saying that contractors trash bags are a good storage idea, you have never stored anything underground (buried in the dirt) for any length of time with a garbage bag…

    I, too, dug a cache up this summer to “see how it went”. I, too, thought that spraying the stuff inside with a rust-inhibitor would be a good way to start – right before I double-bagged and knotted the items as described above.

    The bottom line is: 1) garbage bags aren’t your friend, and 2) spraying with Eezox was a good move – as every rifle (multiple copies of SKS, FAL, and AR) was fixable, and all are in service – in spite of sitting in water for 18 months. We decided to replace the wood SKS stocks.

    Lost about 30% of the m80 7.62×51 that was stored. Same for 5.56×45. Lost 100% of the steel-cased 7.62×39. Mountain House pouches were GTG. We threw the clothing away.

    I live in the PNW, so the ground is wet. I’d suggest using the PVC pipe with glued end caps. Flex seal on threaded cap ends might be a workable deal, but my experience is leading me (for my area) to do “impermeable”. YMMV

    1. I said AT A MINIMUM. You know, like, as in a starting point to be better than sticking metal in the ground?

      Sucks you lost your stuff. Not everywhere is the PNW either.

      The person in question just stuck cans in the ground. Wrong answer. So I made a useful correction, and passed along info which taught me while in the service of Uncle Sam. If you wanna sharpshoot, you can kindly take your ass out the door. Now if you want to change your sour attitude, your input is valued.

      1. brunop

        No sour attitude. I stuck the stuff in bags to see what would happen, knowing that it wasn’t going to be as good as other options. I was letting the readership know that my experience says it isn’t going to work IF you have very wet ground, which is why I pointed out that I live in the PNW. I was also stating another point that agreed with what you stated, which is that spraying / rust preventive is a very good idea.

        Sharpshooting, or stating that it’s a no-go in plenty of areas? I’m not being defensive. OTOH, it’s your show, so you can judge and execute the way you see fit.

      2. Yes I can. And I do, with zero patience for the typical internet BS that goes on in a lot of other places.

        Don’t stick cellulose in swampy ground.

        Roger, out.

      3. Jimbo

        I just shook my head in wonderment (maybe bafflement is a better term, is that a word?) when I read that someone has the swag and a few other unprintable attributes to bury perfectly good rifles in garbage bags “just to see how it goes”, I guess there’s people like that everywhere, more money than good sense. Maybe I can get him to send me a couple of FAL’s, a couple of Glock 19’s, and a pallet of ammo. I’ll bury them here in Texas “just to see how it goes”!

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  10. Numismatist

    Take .50 cal can. Coat the gasket with silicone vacuum seal grease. (NOT vaseline!) Add dessicant. Wrap in Saran.

    Put the can inside a close-fitting bag made of woven fiberglass material. Stitich it closed. Apply catalyzed resin. (One side of the can at at time to avoid excessive heating of the contents during cure.)

    Inspect, recoat any areas that look imperfect, repeat. Make it airtight.

    This can should survive > 25 years of burial in a high water table area without deterioration of the or the contents. It can be a pain to open, though.

    Been there, done this.

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