Modern Ammunition Expiration

['88Scrat]

Just a quick question I wondered about today. What do you think the expiration on a MODERN cartridge would be?

My first guess is the S&B 30-06 I just bought from the CMP will outlive me if stored in a an ammo can on a shelf but by how much? 50 years? 100 years? 500 years?

[Don Fischer]

Originally Posted by '88Scrat

Just a quick question I wondered about today. What do you think the expiration on a MODERN cartridge would be?

My first guess is the S&B 30-06 I just bought from the CMP will outlive me if stored in a an ammo can on a shelf but by how much? 50 years? 100 years? 500 years?

If you buy a box of S&B 30-06 ammo and it last 50yrs, you don't shoot near enough!

[44 AMP]

How long your ammo will last depends mostly on the chemical stability of the powder and primer, as manufactured and as affected by storage conditions.

I don't believe the priming compounds are particularly age sensitive, but smokeless powder, is.

Over time, smokeless powder decomposes, releasing nitric acid fumes. The fumes attack the brass casing making it brittle, often resulting in it cracking as it just sits on the shelf. Eventually the powder becomes completely inert.

Now, the question is, how long does this take? And the answer is, NO ONE KNOWS.

The reason no one knows is that there is simply no way TO know, until it happens, and it can happen differently with each and every single lot of powder, depending on the nuances of the batch of manufacture.

I have seen ammo that was over 100 years old and perfectly viable. I have seen ammo over 100 years old, that had casings cracked and was inert. I have seen ammo headstamped 79/80/81 that had degraded powder to the point of almost 20% failure to fire and 35% of the fired cases cracked.

(that particular lot of ammo very likely had poor storage conditions accelerate the "aging process" but that's just a guess as the actual storage conditions were unknown.

Some years ago there was a rumor about primers being made so as to go inert after a certain amount of time. The rumor was spread around, with the inference that "limited shelf life" primers were part of a gun control conspiracy.

The rumor was just that, a rumor, without any basis in fact. Any chemist (or chemical worker) can tell you that there is no way to make a batch of chemical compound that reliably does that. You can make a compound that degrades at a certain rate, over time, but you cannot make one that does it 100% reliably. A certain percentage will "deactivate" early, and a certain percentage will remain "live" much longer than the target date.

If your ammo doesn't last 20-30 years, I'd say it was bad ammo, something happened to it, either in storage, or during the manufacturing process. 50 years + is not unrealistic, and possibly much longer is possible. One really cannot say any specific batch will last X amount of time, until that time has passed.

The military uses set time periods, and disposes of overage ammo, that is usually fine, but has potentially reached the point where failure could occur.

Odds are good that, given proper storage, you ammo will "outlive" you.

[T. O'Heir]

"...on a shelf..." Depends on where that shelf is located. If it's in a temperature and humidity controlled basement 50 plus years is possible. If it's in your unheated garage it might not last 10 years.
Military issue ammo cans have a rubber gasket that seals 'em tight. That's not going to matter if the room is subject to drastic temperature changes though. That causes condensation inside the can. Mind you, in 100 years, you won't care. snicker.
Oldest ammo I've ever used was some CF issue, 1944 vintage, DA .303 Ball back in the early 80's. It was about 40 some years old at the time. Fabulous stuff it was too.

[Tom-R2]

I found a box of 9mm and a box of 38SPL I had reloaded in the early 1980s sitting in the back of the bottom drawer of my file cabinet. I was surprised to find them, I must have missed them since I don't use that drawer much. They shot fine on the range. Threw the casings in the bucket to reload them again.

[laytonj1]

10 years ago when I was into shooting the 50 BMG, I shot a lot of Lake City ammo headstamped as early as 1942 and a lot of early 1950's headstamps as well. Other than some of it having loose roll crimps (I could spin the bullet in the case) it all fired with no problems.

So, I would say if it is properly stored it would last longer than any of us.

Jim

[kenny53]

I have shot ammo manufactured in the 40's. It shot great.

[jmr40]

I bought a couple of boxes of Norma TAC-223 ammo recently. They have "25 YR, Shelf Life" printed on the box. That is something I've never noticed before on any other ammo purchase.

But I feel pretty confident that if stored carefully ammo could last much longer. Extreme heat and cold cycles would likely shorten the life some. I read once where some hunter found a forgotten box of hunting ammo that had been riding under the seat of his truck for years. He pulled a couple of bullets and the powder inside was a finely ground up powder rather than the normal shape it should have been.

He theorized that bouncing around in the truck for years had changed the stick powder he loaded years earlier to powder. He was afraid to shoot them. I don't know how much, if any that would have changed the powder, but probably wouldn't have shot them either.

[GLK]

Within the past year or so I shot the last of my mil surplus 45 acp ball ammo from the Evansville arsenal & produced in the 1940s. I can assure you it was not kept in climate or humidity controlled storage all those years. I still have original run NORMA 10MM Auto ammo that was manufactured in the late 1980s early 1990s that functions properly and has been stored in a FL garage.

[Danoobie]

I got 1000 rounds of PPU 30.06, it shoots so well, I'm thinking about
replacing my old Garand barrel, in order to shoot up to the ammo's
accuracy.

That said, I've shot poorly made 70 year old war surplus ammo, if I had to guess,
I'd say you could trust that your great-great grandchildren could shoot S&B ammo
made now.

[Oldman11]

I have a 75 yr box of 45-70 that I’m using this year for deer. It’s 500 grain in the two piece box. I just thought it would be nice to hunt with old ammo.

[reinert]

Just a little hi-jack here, but still on with the OP.

Not terribly long ago (10 years or a bit less) I read an article on how long springs would keep their tension, especially in a magazine. Around and around the article went on firearm springs in general and how long they'd stay reliably "springy" in a mag particularly. What I remember most about the article is that there was a story (within the story) of someone finding a WWII era MP 40 hidden in a wall in Germany with a fully loaded mag in place, ready to go. Of course, there had to be a test... the piece fired flawlessly, with every 9MM round shucking out the port, and the mag spring doing its job as it should.

Good old ammo, AND a good old mag spring, too.

[Koolmoose]

I've been shooting my whole life and cannot recall ever seeing an expiration date on a box of ammo. My guess is that any expiration date on a box is the result of opinions from the companies legal department (lawyers talking).

My wife's uncle gave me a box of unopened 22 long that looked like it was from the '40's or 50's. This was in 1976. Every so often I shoot a round from that box and it functions perfectly.

[Bartholomew Roberts]

I've still got (and shoot) .30-06 M2 ball with a Lake City headstamp. Stored well, ammo will probably outlast you. Heck, even ammo not stored so well like that 1980s Guatemalan 5.56 that was on the market about a decade back shot pretty well despite the verdigris.

[44 AMP]

My guess is that any expiration date on a box is the result of opinions from the companies legal department

You will find an "expiration date" on about every product that contains a chemical compound. In food its usually a "best used by" date.

It doesn't mean the product is useless after that date, all it means is, after that date, the maker does not guarantee it is usable.

This is something you can easily see with paints, solvents, glues, etc. If you talk to the maker, they will tell you that if it still mixes up properly isn't dried up, crystalized, etc., it should still work, BUT they won't guarantee it's still good, nor will they stand behind it if it isn't.

I once worked on a project where the end product was required to last 40 years. Because it was required to last 40 years, it was engineered and constructed to last 300 years. That way, the people required to sign off on it were confident it would last 40 years (and also that in 40 years most of them would be retired or dead ) and so they certified it.

Putting a 25year shelf life sticker on a box of ammo is simply something that eases the mind of purchasers, and provides a bit of legal protection for the maker. If the maker says its good for 25 years, then you can be confident that it will be good considerably longer than that, but how much longer, no one can, or will say.

[doofus47]

I have some 30-06 from HSM dated 2008 that is still throwing 1 MOA.
The rest of the boxes of HSM in my stash will probably outlive me.

[mr bolo]

my 30 year old .38 Special reloads from my fathers pistol had a couple of dud rounds when I tried to fire it

it was stored in a dresser drawer for over 30 years

I would say most ammo should last 30 - 40 years, but dont expect it to last forever, nothing lasts forever.