Judy asks:

We have a rather large collection of weapons….handguns, rifles, machine guns. We have alot of stored ammunition in the house. Much of it in surplus military cannisters. (ammo belts, 308, ammo for water cooled weapons, ammo for m60, sten etc) I am concerned that after years of storage that this ammo could degrade and emitt toxic chemicals that we are not aware of. Could you advise? I have been told that it is unlikely…but i still have concerns.

There’s two questions here I want to address. First is the implied question of how long military surplus ammunition lasts. Second is the explicit question of if degrading ammunition can give off harmful chemicals.

As for the first question, the shelf life of military surplus ammunition depends on a number of factors. The most important factors are whether the ammunition was stored in a cool, dry place and whether it was exposed to ammonia, as these will corrode the brass case.

The good news is that most of the military surplus ammunition was sealed in watertight cases following manufacturing.

The best example of this watertight case is the “spam can” that surplus 7.62x54r ammunition (and 7.62×25, and 5.45×39…) comes in. Russia (well, the Soviet Union at the time) was very concerned about possible future invasions, and so designed their ammunition cases to be cached away in every nook and cranny of the country, waiting to be used to fight back the Nazis once more. The benefit for us is that the ammunition is no longer used in the same quantities by the Russian army and available for civilian sale, and thanks to these spam cans the ammunition is in perfect condition even 50 years after it was manufactured.

In theory, the shelf life for modern ammunition is longer than we will ever live to see. Ammunition produced during WWII is still being used by U.S. combat troops in action today, and with modern advances in smokeless powder manufacturing the rate of degradation is much slower than it used to be. However, care should still be taken with older ammunition as smokeless powder does indeed degrade over time (however slowly).

Not all military surplus is so well preserved, however, as the lead picture illustrates. Some poorly stored ammunition may have corroded over time, and the best way to check if your ammunition is good is to visually inspect every round of ammo you put in your gun, paying extra special attention to the primers. If there is any suspicious discoloration, bulging or corroding on the outside of the cartridge then it should not be used and should be discarded. Usually the local gunsmith will be happy to check out any ammunition you have questions about, something I highly recommend taking advantage of. Then again, the old “long-ass string tied to the trigger and hiding behind a tree” method works too.

As for the toxic side of things, there are some hazardous materials in ammunition. The biggest hazard comes from lead, specifically the rather large glob of it on the front of the cartridge (AKA the bullet). The primers also contain some small traces of hazardous elements, but under normal conditions none of these materials should become airborne or even leave the confines of the storage container in which they are housed.

The biggest concern comes from within the cartridge itself. The gunpowder is usually composed of some mixture of collodion (an old developing solution for photographs), nitrocellulose (common explosive screened for at airports) and nitroglycerin (see Alfred Nobel), all highly reactive compounds specifically chosen for their ability to quickly burn and produce gases. Smokeless powder has a tendency to degrade over time, and after a long enough period it will actually produce a purple or reddish vapor which indeed is very toxic to inhale. The good news is that if the ammunition is in tact and the powder is not loose then the vapors will be trapped inside the cartridge, and the better news is that even if that vapor escapes the cartridge the surplus canisters will trap the escaped vapors.

So, in short, degraded gunpowder can indeed give off toxic vapors. But it takes years and years for the gunpowder to degrade, and as long as the ammunition is stored in a cool dry place it should last for decades to come. I’d recommend only opening the older canisters outside in the open air, but anything made within the last 50 years should be golden.

The chances of toxic vapors leaking out of your older ammunition are remote. But, just to be safe, I wouldn’t keep that 1918 vintage canister of .30-06 ammunition under the bed. (All of my ammo is stored on the other side of my apartment near a ventilation duct when not in use.)

[Email your firearms-related questions to “Ask Foghorn” via guntruth@me.com. Click here to browse previous posts]

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30 Responses to Ask Foghorn: Shelf Life for Military Surplus Ammunition?

  1. How do US mil surp ammo cans compare to the spam cans? I’ve got virtually all of my ammo in .50 cal cans.

    • The rubber gasket on the lid of the cans makes them pretty much watertight, so all should be well. I’d just give the gaskets a peek and make sure that all is well (i.e. they aren’t all dried out and cracked).

    • If you are going to use gasket sealed containers for long term storage it never hurts to wet them down with silicone grease, the plumbing variety not spray on.

  2. I’ve used reloaded ammo I made over 25 years ago with no problems, including paper hulled 12 ga, shells. As Nick says, if it has been stored in a place where it does not see extreme temperatures (like repeated cycles from -25 to over 120), and hasn’t been submerged under water during a flood, it should be perfectly fine to use. But if your stuff is from WWII, then I would at least give it a visual inspection as he describes before using it.

    You did mention belted ammo for a machine gun, that I would check as the links are a different metal from the brass cartridge. The links are typically steel and may have corroded where they contact the brass.

  3. I always remind myself that even though surplus 7.62x54R is cheap, it’s still a bit of a gamble with buying. I haven’t gotten my pack of lemons yet but friends have gotten some REALLY bad cases with only fifty or so salvageable rounds. It all depends on whether it’s been stored in a temperature controlled warehouse or thrown into a cave in Siberia. Either one is perfectly plausible considering that it’s Russia and they’ve got the space and the ammo to fill it.

  4. I’ve bought several ammo cans of 30.06 from the CMP for my Garand. I’ve thoroughly inspected each round and found some, about 4-5%, that appeared to have corrosion on the case. Each one of these I have scrubbed with a Mr. Clean “Magic Eraser.” Minor surface discoloration and light corrosion generally comes right off. If the surface is in any way pitted after “cleaning” this it goes in the disposal can along with any found to have dents, dings, etc.

  5. In the military, ammo gets moved from tactical use stocks into training use as it approaches it’s “shelf life”. Having fired from both stocks with auto and semiauto weapons, the probability of FTF, FTE, stovepipes and other malfunctions increase greatly (my own non-empirical estimates) from less than .5% to up to 1% with the older training ammo.

    • It is my firmly held opinion that this is ideal. Stoppages happen in combat, and the only way to effectively train to deal with them is to have to clear them when shooting.

      If not for a case of ammo my carry piece didn’t like I wouldn’t have become as proficient at clearing jams/misfeeds.

      • Very good point. Train for malfunctions when it doesn’t count; pray they don’t happen when it does.

  6. Under good conditions smokeless powder will last longer than you will. I’ve some pre WWII .303 ammo that goes bang every time. It’s loaded in paper boxes so has never had the benefit of a sealed can. Even the cordite stuff still shoots fine. I’ll never forget pulling the bullet on one of them and wondering why the hell they loaded it with spaghetti.

    I remember reading that Hercules (Alliant now) has batches of Bullseye over 100 years old that still test to specification. Of course the canisters are kept in sealed containers immersed in temperature controlled water but you get the idea.

  7. “the old “long-ass string tied to the trigger and hiding behind a tree” method”

    Ah, yes. The Rocky Mountain proof.

  8. I also have a cache of .30 and .50 cal. ammo cans full of ammo, I throw in those little desi pacs and rotate them as I live in a humid southern state.

    I have Argentine Mauser 7.65 x 54, milsurp ammo manufactured in the 70’s that still goes off without a hitch. Same for the CMP Garand ammo. Also give a quick glance to the primer(s) for any scale or residual crud that’s greenish in color. If it doesn’t look right, dispose of the round. Better to be safe than have a kaboom.

    Still have some Korean War Era .45 ACP Ball. Smokes more, dirtier, but still works.
    If stored properly, let alone the spam cans, it will last decades.

  9. I got some old .22 ammo from my dad that he had purchased back in 1963 and has had it in the original paper boxes of 50 ea.

    Aside from some oxidizing on some of the rounds that got wet, they have all gone boom in his 1964 marlin.

    I was amazed that this rifle had hung on his gun rack for 40+ years and with one cleaning it still shoots like a new gun with the old tried & true iron sights and rimfire ammo from yesteryear!

    • +1
      Last year I fired two Beretta magazines of .22LR my father loaded in 1953. The casing brass was green but all 20 rounds worked just fine.

      I guess this should also set to rest any concerns I’ve ever had about keeping magazine springs compressed or how long a pistol can be kept cocked and locked!

  10. Hey, that photo looks familiar! That’s that crappy Israeli surplus ammo I bought from R-Guns. I can’t believe those tools at R Guns would sell such crap without disclosure.

      • I though that ammo looked familiar! Joe showed it to me at his office a couple of years ago.

        I suspect that those rounds were either 1) salvaged from a sunken transport ship at the bottom of the Mediterranean, 2) found in belts inside a rusted-out Israeli tank from the Yom Kippur War, where it had been urinated on by decades of feral goats, or 3) stored in sealed vats of ‘Senor Limon’ lemon juice, deep in the Bolivian jungle.

        That ammo was absolute crap.

  11. You could use a sealed spam can of Russian ammo for a pillow and not have to worry about toxic fumes. Those cans are tight.

  12. I have shot ammo that was stored for decades in cardboard boxes in a basement. They all tended to go bang.

  13. The only ancient ammo I ever had a problem with was a bandolier of .303 which was probably loaded with Cordite from the Boer War, and some similarly antediluvian 8mm Mauser. These rounds were possibly WWI leftovers from their markings, which we took an interest in once we decided not to shoot any more of them.

    We learned that it’s not a good idea to shoot ‘surplus’ ammo in a caliber that hasn’t been used by any military in more than 30 years. Not everything gets stored properly for that long.

  14. Before I knew any better, I bought some Pakistani .303 from Aim Surplus. Usually Aim does me right, but this Paki stuff was crap. It went “bang” an all, but there was sometimes up to a 1/2 second delay between trigger pull and ignition. It felt exactly like the delay you experience when you shoot black-powder. I think I still hvae a few hundered rounds of it. One of these days i’ll pull the components and reload it. Or not.

  15. Nick, if you’re ever in the Houston area let me know as I would love to take you to some local ranges. East Texas also has some great hunting.

    If you stop using R I might have to slap you as a fellow statistical programmer.

    Keep the content coming.

  16. Read an article in Muzzle Blasts magazine (NMLRA) a few years back, where they tested some original commercial black powder (sulfur, charcoal, saltpeter) from the late 1800s. It had been kept in sealed, original cans in a cool dry environment. When compared to a batch of similar new black powder, it gave nearly the same velocities and pressure curve. There was a slight decrease in velocity, but it was not statistically significant.

    Like you said, the key is storage conditions. Don’t keep it in your leaky basement or in your attic or uninsulated garage. I wouldn’t buy surplus ammo from countries where heat and humidity are common.

  17. The MSM has made way too big a push on minute quantities of “toxic chemicals” for the last few years. I know that “fear” sells but…… There are no such things as “nontoxic chemicals” only nontoxic doses. If you have totally sealed your house and stopped even normal ventilation then you are at much worse risk from cooking fumes than stored sealed ammunition.

  18. In the early seventies my father in law worked at a landfill. He brought me 20-30 rounds of preWW1 45ACP someone had discarded. A few had holes corroded in the cases and would not fire, but the ones with the cases intact fired and cycled normally and had the usual amount of recoil so I assume the muzzle velocity wasn’t far off from normal. 60-70 year old ammo and it worked fine except as noted. I still have some of them left somewhere in my ammo dump but am saving them as collectors items.

  19. I have used the Russian 7.62X54R spam cans in both of my Mosin Nagants for years. I have never had one misfire, or no fire. They’re cheap and very reliable in my opinion. I had ordered 500 8mm Mauser surplus, out of the 300 or so i have used so far, I only had about 5 no fires. Not too bad for 60 year old ammo.

  20. Would a brief exposure to water affect WWII rifle ammo? for example, most guys at Tarawa and Normandy got soaked on the way to the beach. Were their firearm less reliable and a result of the ammo being wet?

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