Ammunition storage/expiration

[VirginiaCat]

Ok guys,

I am accumulating ammo. And enough that I will not use it for practice.

Currently storying in my Master BR Closet. I have a basement, and it does not leak and is Temp controlled but..just feel better on the 2nd floor.

Saying all that, what is its longevity in that storage situation?

[Darrell KSR]

One of the experts will chime in. I know I have read that modern ammunition is good for a decade or more, properly stored. I had always been told that my ammunition would outlive me.

[CitizenBBN]

I have shot 22 that is decades old, and as ammo goes 22 is the least well sealed ammo IMO.

If kept dry it should last decades, if not indefinitely. Some disagree on this point, but I have shot old ammo and powder is extremely stable as long as it doesn't get wet. Primarily therefore you are battling moisture in the air and the seal of the ammo.

Modern ammo is well sealed but not entirely waterproof or moisture proof. In fact I just read a study on water that had been flooded. Much of it was still operable ammo. You wouldn't want to bet your life on it but it was OK for target b/c it was going to be 80% or so per this one study.

This moisture issue is why the ammo can was developed. Originally done in foil sealed packs and wood crates, now packed in metal tins with seals. Also you can buy "spam cans" which are pre sealed tins like a tin can, complete with old school can opener.

If sealed from moisture I would say indefinite. Some say 10 years, some longer, but in my experience as long as you keep moisture off of ammo I am with those who told Darrell the ammo would outlive him.

It is true though that the seal around the bullet and the casing is NOT waterproof and moisture proof indefinitely, and esp. if you start to get moisture it will work its way in by deteriorating that seal over time.

This means reloads are more susceptible, and remanufactured ammo may be as well.

I would endeavor to seal up ammo in well sealed metal ammo cans. Now my ammo can talk...... I know you're excited.....

These cheap Chinese "ammo cans" with plastic and really crappy seals on the lid are NOT water proof. I've tested them. That means they are not water vapor proof either. It's b/c the hinges and seals are so poorly made, it's too easy for them to have gaps.

Better quality plastic boxes are fine, IF the rubber gasket is very good quality. You want something with a grooved gasket seal so you have plenty of surface area of rubber contacting the box, and you want a good quality rubber that will hold up a long while.

Mil spec boxes are best, b/c they really clamp down well and have good gaskets. Also you can look for long term food storage containers, anything that is moisture impermeable and has a really good seal.

The best option IMO is the spam can, pre-sealed ammo in cans.

Last and way out there option is to "can" the ammo yourself. Seriously. Food prep guys have videos for this, where you can buy your own #10 cans and sealer and then you can seal the ammo up in it. I have not done this, seems overkill, but I guess it would keep it decades longer b/c water would have to rust through the entire can and then work on the ammo.


Dryness is the key. Just like with guns. A lot of people also use desiccant packs, which work OK, but you need a lot of it for your volume of air, you still need sealed containers and you have to keep checking it. I use some just as a warning alarm as it changes colors when it absorbs moisture. If it turns color you have moisture.

[dan_bgblue]

If you are talking modern rifle/pistol ammo with brass casings and shotshells with brass powder and primers and plastic shot chambers, I would say that the 10 year time frame is certainly a reasonable number, I have some .410 cartridges that are 60 years old and they are of the modern variety, not paper casings, and I shot one about 5 years ago and it went boom just as designed. Bomb demo crews are still blowing up a few a year in England and some of them have been under water since the 1940s. I know that is not a 9mm modern piece of ammo but the principle is the sane. CBBN or suncat may tell me I am completely wrong but that has been my limited experience.

[suncat05]

No dan, you're right on point.

And everything CBBN said was right on point too. Especially about the metal ammo cans with a good rubber seal. I only use mil-spec ammo cans with good rubber seals for my ammo. And CBBN is on point about the desiccant packs as well.

As long as the place(s) where you store your ammo are climate controlled and remain dry, your ammo will be good. And not only will it outlive Darrell, but the next generation of Darrell's progeny as well.

[Darrell KSR]

Picked up two more ammunition boxes tonight on a whim. Guess I need to buy some more ammo.

[CitizenBBN]

Can never have enough ammo. Now I wouldn't spend the mortgage money on it, or your wife's birthday present money either, b/c that would be worse than just running out of ammo in that theoretical distopian world, but can't hurt to have plenty if it fits the budget.

It's funny to me b/c I get ammo out of estates to sell at times that is 50,60,70+ years old, and afaik it all shoots just fine, and was stored in no special way. We find old 22 with corrosion on the cases and you test a round and it fires fine. You may get a dud once in while with it, and I don't run it through a chronograph so it may have some less power, but overall it's still usable ammo even once the cases and lead turn green.

Brass case ammo is shockingly long lived, even if you don't baby it. No doubt about it. If you baby it in mil-spec cans with desiccant and packed with nitrogen infused cases, etc. and so on, I can't see it going bad for a century or even centuries.