Ammo shelf life


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mini14gb
January 12, 2011, 01:05 PM
How long can American manufactured ammo last on the shelf? I'm not really concerned about it but I recently bought some PMC and Remington manufactured 5.56 (.223) from a guy. I got 900 rounds for $5 per box. I asked him how old it was and he said he thought he bought it in 1999. Turns out it was bought in 1997 which is fine.

I KNOW THE AMMO IS GOOD TO GO but it begged the question in my mind, what is the shelf life of non-corrosive ammo that has been properly stored?

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M-Cameron
January 12, 2011, 01:15 PM
i dont actually think there is anything that deteriorates in modern ammunition.....

...so as long as its stored properly, im willing to bet it doesnt really go bad....

Offfhand
January 12, 2011, 01:18 PM
1997? That's almost new! And will probably be good for at least another half century, probably longer. I'm still shooting some LC Match '63 that's as good as new.

HOOfan_1
January 12, 2011, 02:32 PM
I've picked up recently fired 8mm surplus at the range which was marked 1943

mini14gb
January 12, 2011, 03:10 PM
1997? That's almost new! And will probably be good for at least another half century, probably longer. I'm still shooting some LC Match '63 that's as good as new.

As I said I know the ammo is fine. I've never heard a discussion about the maximum life of modern ammo. Somebody out there has to have some knowledge beyond the age of the ammo they have personally used.

JohnBT
January 12, 2011, 03:27 PM
Lead bullets exposed to the air for long periods can oxidize and it really isn't too good for you or the barrel (I'm told.) But it will fire.

Other than that, I'm guessing a century give or take a couple of decades.

I had a half a box of .38 S&W blanks go bad, but I'm guessing they were from the '40s or early '50s just from the printing and artwork on the box. Not one of them fired.

CoRoMo
January 12, 2011, 03:29 PM
It can last longer on the shelf that you could.

RNB65
January 12, 2011, 03:39 PM
I've got about 4000 rounds of 7.62x54R that was manufactured in 1953. It looks and shoots as well as the day it was made. As long as the ammo hasn't been stored in a very damp environment that invites case corrosion, you're good to go.

SlamFire1
January 12, 2011, 03:52 PM
Double based and single based powders start deteriorating the day they leave the factory. Nitroglycerine and nitrocellulose want to combine to form a lower energy compound. Nitric acid gas is released as a by product of this reaction.

The reaction rate is directly proportional to heat. The hotter things are, the faster the migration and reactions.

The Navy initially test for acid gas by the Methly Violet test, or Talliani test. If acid gas is detected than a chemical analysis is performed to determine the amount of stabilizer in the powder. (Stabilizer is either MNA or 2-NDPA)
When the concentration of stabilizer is LT or EQ to 20% of the original content, the Navy scrapes the lot.


The Army does things different. They scrap based on clock time. 20 years for double based powders, 45 years for single base.

Per an energetics expert I know, the best storage conditions for powder is arctic cold. That is cold and dry. He said water exposure damages powder.


http://www.almc.army.mil/alog/issues/JulAug08/propellant_stab_eq.html

The U.S. military has stockpiles of ammunition, new and old, that can present safety hazards. The primary ingredient of the propellant used in these rounds, nitrocellulose, can deteriorate with age and become prone to auto ignition. To avoid the destruction that could occur from the self-ignition of this propellant, the Department of Defense (DOD) has established a program for testing ammunition stocks to determine the thermal stability of the nitrocellulose propellants they contain.
More reading on this subject:

www.dtic.mil/dticasd/sbir/sbir031/n154.doc

mini14gb
January 12, 2011, 04:24 PM
SlamFire1,

Thank you for that post. Informative. That was more along the lines of what I was looking for.

Rmiller31
January 12, 2011, 06:17 PM
I shot some ammo the other day from my 1873 Winchester 32-20 that was from the 50s. Don't remember the exact date but it was flawless.

Something fun about shooting a rifle that's over 100 years old and ammo over 50 years old!

Average Joe
January 12, 2011, 06:45 PM
Never

JohnBT
January 12, 2011, 07:58 PM
They say powder goes bad, but it's very humid here and I've never noticed a performance dropoff. But I don't store my ammo outside in the sun or underground either.

heeler
January 12, 2011, 08:07 PM
Well a couple of weeks ago my brother gave me a call and told me he found some old 20 gauge ammo that believe it or not was sold by the 7-11 conveince store chain to him back in the early 70's during dove season.
This ammo was in a box of camping equipment stored in a closet where he stumbled across it.
He took it with him when he went to finish out the last weekend of deer season and it shot just fine.

HOWARD J
January 12, 2011, 08:20 PM
Keep it dry & store it in a air tight container & it will last longer than you will be able to shoot.

WardenWolf
January 12, 2011, 08:26 PM
Modern ammo, with sealed primers, will last practically forever. Old wartime ammo from World War II sometimes did not have sealed primers, as a cost-saving measure (the ammo was being shot as fast as it could be made, so why bother making it so it would last 20+ years?). This was particularly true for pistol and submachine gun ammo like .45 ACP.

As for heat affecting ammo, my father used to store his ammo in the garage, in Phoenix, Arizona, where temperatures regularly reached around 130 degrees in the summer. Some of that ammo was in there for a decade or more. It always shot just fine.

Tommygunn
January 12, 2011, 08:33 PM
I've fired .30 Carbine ammo dated 44 or 45 and it worked fine.

Hatterasguy
January 12, 2011, 10:07 PM
As long as its kept dry I would say 50-100 years if not more.

The Russian spam can stuff will probably still look and work ok when its 200 years old. Its really well sealed, my 1970's vintage looks and shoots like new manufacture.

jmr40
January 12, 2011, 10:53 PM
Slamfire provided some pretty good info and links to back up his comments.

Just becase 50 year old ammo goes bang, and the bullet leaves the barrel does not mean it is providing satisfactory performance.

Using old ammo for plinking is probably not dangerous, but for hunting or personal defense use I'd prefer something a little newer.

Jeff F
January 13, 2011, 08:49 AM
I shot up some .45acp that was dated 41 and 43. Not one failure in 87 rounds fired.

JohnBT
January 13, 2011, 10:34 AM
"Just becase 50 year old ammo goes bang, and the bullet leaves the barrel does not mean it is providing satisfactory performance."

If it hits the same place on the target as the new ammo I'm shooting that day I assume that the performance hasn't degraded to any meaningful degree.

aka108
January 13, 2011, 10:41 AM
Some of the nicest shooting 6.5 Swedish i ever shot was last year. The ammo was Swede manufactured in 1924 and 1926. That's a little over 80 years in storage.

SlamFire1
January 13, 2011, 11:04 AM
Just because 50 year old ammo goes bang, and the bullet leaves the barrel does not mean it is providing satisfactory performance.
I appreciate the words of support.

If you read the references, ask the experts, gunpowder aging is 100% correlated to storage conditions, most specifically heat.

The basic problem the munitions community has is when to dispose of this stuff prior to it going poof. :what:

Unfortunately, as robust as it is, our propellant surveillance system has not put an end to autoignition accidents. Seven propellant autoignition incidents, some involving 100,000 pounds or more of powder, occurred at Army installations in the 1980s and 1990s. Although it has been 10 years since the last accident, constant vigilance is required.http://www.almc.army.mil/alog/issues...t_stab_eq.html

I put this information out to help dispel the myth and legends, and because I too had been following “conventional wisdom”, which more times than naught, is not much more than superstition.

The expert which I talked to told me that as gun powder ages the surface changes. For double based powders, the surface becomes nitroglycerine (NG) rich. This alters the burn rate even though the total energy content of the powder is being reduced through deterioration by the reduction-oxidation process, the pressures can and do spike when there is too much NG on the surface.

I shot old surplus IMR 4895 which was going bad, it shot very well, but I remember unusual sounding muzzle blasts. This stuff was outgassing enough nitric acid gas that it caused case neck cracks and corrosion on the bottom of bullets. It was not very long before I poured that stuff out on the lawn.

I was given a handful of 30-40 Krag ammunition from 1898. Each and every cartridge had a cracked case neck. I pulled the bullet from one case and looked at the powder, it is almost a ruby red. Quite attractive. When I mentioned this to the expert, he squeaked like a mouse. :eek:


I am certain the stuff will go bang in some fashion. But I am not going to try and find out if it will shear the locking lug on my Krag.


Using old ammo for plinking is probably not dangerous, but for hunting or personal defense use I'd prefer something a little newer.I basically agree. If the cases are not corroded through, the case necks are not cracked, and the muzzle blasts don't change, heck shoot it up. But shoot it up soon, old ammunition does not get better with age.

You can leave a twinky on the shelf for 30 years, http://articles.sfgate.com/2004-08-12/news/17437230_1_twinkie-innovative-teacher-shelf-life, does not mean that I am going to eat the thing.

But you will find people who will :uhoh:

Some of the nicest shooting 6.5 Swedish i ever shot was last year. The ammo was Swede manufactured in 1924 and 1926. That's a little over 80 years in storage.

I will bet ammunition storage depots in the American southwest get a lot hotter than Swedish depots. http://www.climatetemp.info/sweden/#imperial )

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