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Old February 2, 2013, 02:56 PM   #1
bluewaterlover
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how long is powder good

hi all, just joined today. I found a bottle of unique powder in the back of my reloading cabinet -- date code on bottle is 94 -- seal was never broken on the bottle -- is it still ok to use? does powder get weaker or stronger over time? thanks in adavance for your help.
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Old February 2, 2013, 03:54 PM   #2
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This question comes up a lot. I am still using powders I bought in the 60s. Powder can deteriorate over time. It depends a lot on how it has been stored. If it smells acrid or looks rusty, sprinkle it on your lawn.
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Old February 2, 2013, 03:58 PM   #3
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Old February 2, 2013, 09:09 PM   #4
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Gunpowder will keep virtually forever so long as its kept in a cool dry place. I don't know much about the degredation of it. From what I hear there is never a real difference in performance with age.
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Old February 2, 2013, 09:30 PM   #5
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Quote:
Gunpowder will keep virtually forever so long as its kept in a cool dry place.
What I was told the best storage conditions are arctic. Absolutely unchanging cold and bone dry. I saw a show and I think they were finding plant pieces from millions of years ago in the Arctic. They were freeze dried.

But, short of that, powder is going to degrade.



Quote:
I don't know much about the degredation of it. From what I hear there is never a real difference in performance with age
There are literally tens of thousands, perhaps more, people working in an specialty called “insensitive munitions”. These are the experts and they cull out hundreds of thousands of tones of old small arms ammunition each year because the stuff is beyond its shelf life. Smokeless propellants degrade. When it degrades the quality of the ammunition gets worse, gets dangerous to the user and in large enough quantities, spontaneously catches fire. At least one ammunition dump explodes each month in the world. Just google it.

Heat is the absolute worst enemy to smokeless propellants but chemicals, water, anything ionic, will accelerate the decomposition of nitrocellulose based powders. Gunpowder as we know is deteriorating the day it leaves the factory. Gunpowder is a high energy molecule that is breaking down to a low energy molecule.

The experts have a number of tests to determine whether gunpowder should be scrapped or not. None of us here have the ability to test stabilizer content in our powder so the best we can do is apply rules of thumb and look for gross indications of powder deterioration.

The rule of thumb for powder kept in 70ish temperature conditions is a 20 year safe shelf life for double based and 45 year for single based.

If powder smells bitter, looks red, it is well past its shelf life.

Old powder outgases NOx. If you smell a bitter smell it is NOx, and the powder is way past unsafe.

Powders that have no smell may be past a safe shelf life. These cases were loaded a year ago with my last batch of surplus IMR 4895. Upon firing I had an unusual number of cases crack at the case neck and I even got case head separations. This is an indication that the powder is outgassing NOx . One of the byproducts of NOx is nitric acid gas, that will attack brass. The powder shot excellent groups during testing, it does not smell, but now I am really pondering what to do with it. I hate losing 16 lbs of powder, but I know it is not to be trusted. I will probably end up pouring it out.



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Old February 3, 2013, 12:11 AM   #6
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Great advice above. Smokeless powder is good, until it turns bad. You need to check it like above, and if its good use it. If any doubt flush it.

There are people loading WWII surplus still, and others with a couple decade old stuff gone bad.
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Old February 3, 2013, 12:18 AM   #7
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I am using some that is over 25yrs old now, and it does fine in my handguns with no evidence of any problems.
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Old February 3, 2013, 12:33 PM   #8
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Let me add, if your powder dates from 1994, go use it. There have been some notices of 80's powders that went bad in the can, if you can does not look like this, and reddish rust does not waft its way when pouring the powder, your powder is probably good.

I have recently loaded some 1992 vintage IMR 4064, there were little rust spots in the tin, a neutral smell to the powder, but I am shooting it up as fast as I can.




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Old February 4, 2013, 11:49 PM   #9
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Pour some onto a white sheet of paper and look at it. Any red dust, use it for fertilizer. If not use it and love it. A year or so ago I went through a few pounds from the 80's and it was fine.
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Old February 5, 2013, 07:20 AM   #10
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I just finished loading and shooting some 45 acp with Bullseye and some with Unique that was from the mid 70's. They both worked fine with no problems.
I had bought a new lb of Bullseye and put some of it and some of the old on white 3x5 cards, they both smelled the same and looked the same.
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Old February 5, 2013, 10:07 AM   #11
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The British military uses 20 years for double-base powders and 45 years for single base powder as maximum safe stockpile time. Actual deterioration can be far different. A few years ago there were reports of one lot of 4350 that was going bad in cans in just three years. Very odd, but several folks reported it. So just examine the powder.

The military used 18 months at 140° to intentionally use up stabilizers in one set of tests. If you figure you roughly double the rate of deterioration every 18°F (10°C) increase in temperature, then at 68°F it should last 16 times longer or 24 years. At 57°F (wine cellar) it should last 37 years. That said, the single-base stuff often keeps working longer. And Alliant has some 100 year old Unique (a double-base powder) that is kept under water (it's original formulation wasn't deteriorated by moisture, but Alliant tells me that's not true of modern powder formulations) that still performs normally when a sample is dried and tested. So there are complexities imposed by other ingredients and storage condition factors.

The red rust color and acrid odor are pretty strong indicators of trouble, as is an oily surface that clumps the grains. I would not rely on lack of scent. The normal powder scent is due to evaporation of residual ethyl acetate solvent used to form the grains. If you store powder in a desiccated environment, that solvent will leave the powder faster than in a humid environment, so I don't think you can count on that smell as a consistent indicator of powder condition.
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Old February 5, 2013, 11:18 AM   #12
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This came from the Propellant Management Guide Dec 2003 version.


These guys are primarily concerned with keeping ammunition depots from blowing up.

But, the same nitrocellulose (single base) and the same nitrocellulose and nitroglycerine (double base) that you use, they use in many things.

Just take a look at all auto ignition incidents you never heard about till now: (and they are only Army!)


1-4. BACKGROUND

a. Propellants and propelling charges that we store, transport and maintain warrant our special attention. Among commonly stored energetic materials, only nitrate ester-based propellants (principally nitrocellulose-based ones) have the propensity to spontaneously combust (self-ignite, autoignite) without warning while sitting in storage; catastrophic losses can result. Artillery and Small Arms propellants are perhaps the most dangerous materials that Army installations routinely handle and store. Propellant can be unpredictable, decomposing into an unstable condition within four or five years of manufacture. Inadequate propellant safety programs have contributed to several self-ignition incidents at military and commercial installations in the United States and abroad.

b. When grains, flakes, sticks or sheets of propellant inside a container ignite, sufficient heat and flame is produced to ignite the remaining propellant material in that container. If unstable propellant is present in even minimal quantities (e.g., a single container), it might combust and could lead to ignition of the entire contents of the storage structure. Propellant burns at a very rapid rate in a process that is known as deflagration. Deflagration differs significantly from detonation in that deflagration involves very rapid combustion that takes place on the surface of the propellant. Detonation, on the other hand, occurs due to a different process that involves a shock wave moving at supersonic speeds through the explosive material, thereby causing its nearly immediate decomposition. Simply put, deflagration operates on the basis of heat transfer, while detonation operates on the basis of a shock wave.

c. During the period 1984 through 1997, seven propellant autoignition events occurred at U.S. Army Materiel Command (AMC) installations.

1. 1984: Lake City AAP
IMR powder that was only 5 years old autoignited and the above ground magazine & its contents were destroyed. More than 100,000 lbs of powder deflagrated.

2. 1984: Lake City AAP
The same lot of IMR powder, a fragment quantity isolated and saved for critical production testing, autoignited two months after the previous fire. Only a small quantity of powder was lost, but another magazine was destroyed.

3. 1985: Blue Grass Army Depot
The local-stocks storage magazine use for demilitarization activities contained high explosives material as well as unmonitored M10 propellant powder. Autoignition of the powder and its resulting deflagration gradually ignited the other energetic materials present. The earth covered magazine and its contents were destroyed.

4. 1987: Lone Star AAP
Benite was stored in a heated magazine so that it could be temperature conditioned prior to loading into production items. The building became overheated which accelerated the rate of decomposition of the benite to a point that autoignition occurred. The structure and contents were lost.

5. 1989: Hawthorne Army Depot
8-inch, 55-caliber propelling charges loaded with single-base propellant autoignited in an earth-covered magazine more than one year after the Navy ordered the lot destroyed due to low stability. The magazine contents of 30,715 lbs of various propellants were destroyed, and the magazine was heavily damaged.

6. 1996: Red River Army Depot
Expulsion charge assemblies for large caliber artillery rounds, each charge filled with only one ounce of M10 propellant and stored 250 to a box, autoignited. The earth-covered magazine and its contents were totally destroyed.

7. 1997: Hawthorne Army Depot
M9 flake propellant bags that had been removed from 81MM mortar rounds were bulk-packed and placed into long-term storage. A container of unstable propellant autoignited, and all 20,000 lbs of propellant inside the earth-covered magazine were destroyed. The magazine was severely damaged. Value of contents lost was more than $3,000,000, while the cost to repair the magazine was $164,000.
d. Accidental autoignition of propellant occurs at other than Army facilities, too. During the same time period as the incidents above, propellant self-ignition accidents have occurred at Navy facilities and at privately owned industrial storage sites. If you consider the number of accidents versus the limited number of locations that store artillery and small arms propellants, you begin to realize that the chances of having an accident happen at your installation are not as unlikely as you may have imagined.


At first I thought SAAMI powder storage recommendations as to quantity and containers were alarmist or just off the wall, but with enough education, I can see their concerns.
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Old February 5, 2013, 10:58 PM   #13
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Slamfire--So if powder is stored in the original container and kept below 72 degrees F is autoignition a risk? I have some Blue Dot and 4350 that is coming on 10 years old. Also a couple of cans of old H4895 that may be pushing 30 years old, and were probably kept in a garage for 10 years (I inherited the stuff). It looks just like new (just checked) and smells weakly of solvent. I have shot some of the rounds that were loaded back when with the 4895 and they work just fine.

I suppose a loader should routinely check all of the powder on the shelf and make sure nothing is amiss. Hate like heck to burn the house down with a $20 can of powder for being a tight a** and keeping it rather than throw it on the lawn.
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Old February 6, 2013, 11:03 AM   #14
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Quote:
Slamfire--So if powder is stored in the original container and kept below 72 degrees F is autoignition a risk? I have some Blue Dot and 4350 that is coming on 10 years old. Also a couple of cans of old H4895 that may be pushing 30 years old, and were probably kept in a garage for 10 years (I inherited the stuff). It looks just like new (just checked) and smells weakly of solvent. I have shot some of the rounds that were loaded back when with the 4895 and they work just fine.

I suppose a loader should routinely check all of the powder on the shelf and make sure nothing is amiss. Hate like heck to burn the house down with a $20 can of powder for being a tight a** and keeping it rather than throw it on the lawn.

This is not an easy question to answer. Literally millions are spent every year by militaries to determine if their stockpiles of smokeless propellants are good. These guys have conventions where they exchange information. There are all sorts of propellant tests. If you want to see all the different tests the military has, look at Mils Std 286 Propellants, Solid: Sampling, Examination and Testing to be found at https://assist.daps.dla.mil/quicksearch/.

If you look at this UN document,
IATG 07.20 Surveillance and in-service proof

http://www.un.org/disarmament/convar...ement(V.1).pdf

Section 7.3 “ Climatic impact on the degradation of explosives” has an interesting table 1, for how long munitions should last if exposed to heat. Should does not mean "will".

When I have read and heard from insensitive munitions experts, it seems the risk of auto ignition increases with powder bulk. There is a theory that smaller ammunition (five inch shell or less) won’t auto combust in the case because the mass of metal will conduct heat rapidly enough to keep temperatures below auto ignition temps. One IM expert I know said that this is bogus, but you will see terms like “5 inch rule” in the insensitive munitions literature.

Both SAAMI and Alliant tell you to look for the gross signs of powder deterioration:

http://www.saami.org/specifications_...ess_Powder.pdf

http://www.alliantpowder.com/getting..._handling.aspx

Home owners don’t own sophisticated test labs which conduct tests for chemical analysis and percentage of stabilizer in the powder. All you can do is look for gross indications that your powder has gone bad.

I recommend opening the tins/cans on occasion. The idea that powder in a sealed container won't go bad is bogus. Look and sniff. I recommend keeping powder in the original containers, I think smaller is better. Anyone pouring all their powder into five gallon drums is asking for trouble.
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Old February 6, 2013, 04:13 PM   #15
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Thanks for the links Slamfire. Rather dry reading for an old farm boy turned city slicker.

Your comments about lifting the lid and inspecting each jug of powder on a regular basis makes good sense. In 1 pound jugs in the basement in Colorado (where the relative humidity is usually about 20% or less) it should be good for a year at a time, it seems.

I have wanted to try that old H4895 and may give it go. I have the Hornady book that was used to make the loads 30 years ago, so that data should be a good starting place.

Thanks again.
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Old February 6, 2013, 05:22 PM   #16
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Actually, I would check that old data against current data. I have the Hornady 2nd Edition data, and it was developed in production guns by pressure sign rather than in pressure test barrels. Some of it's a bit warm as a result. If the modern data has smaller charge weights, start with that.
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Old February 6, 2013, 06:19 PM   #17
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Good idea--

Thanks, Uncle Nick- Already did that, and for the 22-250 the loads are only different by 0.1 grains. Will start with min loads and work up. I seldom shoot the max load of anything. Groups size (after a fairly moderate velocity for a given cartridge is obtained) is the maiin objective for me. Since Varget is unobtainable right now, and the load data shows the 204 Ruger with Berger bullets and H4895 as comprable to Varget, it makes sense to me to waste a few rounds seeing if the old powder will work at this time. Besides, I like using old Grampa Horace's stuff. I think it would make him smile. Makes me smile.

Really appreciate evryone's opnions and thoughts.
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Old February 6, 2013, 07:56 PM   #18
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Seeing as you guys are on the subject. How about WWII ammo. I have shot a fair amount with no problem. I think its fair to say I dont know how it was stored over the years seeing as I was born at the end of Vietnam. Did I just get lucky or is it generally accepted as shootable?
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Old February 7, 2013, 10:21 AM   #19
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The older the ammunition the less predictable. Where the ammunition was stored and the conditions it was made is something you don’t know unless you have owned it since the day it was made.

Priorities for things made in wartime are different than things made in peacetime. The bigger the war the less concern there is for “the long term”. From what little I have found in literature, the number one priority in WW2 was “getting the stuff out the door”. There was no expectation about 20 year, 45 year shelf usage. The country was either going to win this war, or we were going to be a German or Japanese speaking people. So much war material was sunk by U-Boats, destroyed in combat, before use, that putting time and effort into making something perfect did not make a lot of sense.

As an example, take a look at the last ditch weapons of the Germans and Japanese.

Also, take a look at the workmanship of WW2 Garands and the nice surface finishes of the post war Garands.

So combined with age and the haste of manufacture, WW2 ammunition is far from predictable.

I purchased several thousand rounds of WW2 ammunition back in the 80’s. I did not know about ammunition aging, but I found lots of cases which corrosion had eaten its way through the case. I fired the cases without pinhole corrosion. Later I examined all of those fired cases with a flashlight.A lot of them were internally corroded and I tossed those out. In fact, in time I tossed all of my WW2 30-06 cases. At the time, it all went bang, I don’t recall any pressure problems, but, I was lucky. Old ammunition that shows obvious signs of deterioration should have every bullet pulled and the powder dumped. Then examine the cases for corrosion.

When I learned of the mechanisms of powder aging, it is a reduction-oxidation of the double bonds in nitrocellulose, I talked to friends about the risks of old ammunition. One bud, who is a machine gunner, told me that what I told him explained the two “top cover” blowups he had had with 1950’s Yugo 8mm in his machine guns. Machine gunners shoot a lot more ammunition than rifle shooters and they want the cheapest ammunition. I bet if I knew more machine gunners I would hear more surplus ammunition blowups.

Blowup stores are rare, people try to make sense of the events and they assign reasons that are based on conventional wisdom. If they have not been taught that old ammunition can cause pressure issues, they won’t be looking for that as an answer. I found this true of slamfires. For decades people were taught the only causes for slamfires were high primers and worn out Garand/M1a receiver bridges. Primer sensitivity, the primary non mechanical cause of slamfires, did not exist. So when you look at posts about slamfires, the root cause is almost 100% believed to be high primers, even when the shooter is using factory ammunition.

Anyway I have a few posts that I am of the opinion that the blowups were due to old ammunition. I am having to break this up into several posts due to the six picture limitation on this site.


Garand Blowup with WWII ball

http://www.thehighroad.org/showpost....3&postcount=13

Quote:
I have an old shooting buddy who some years ago was shooting some WWII ball (don’t know whose) but his M-1 was disassembled in a rather rapid fashion. He was lucky only his pride was hurt. He said he took a round apart and found rust looking dust along with the powder. Bad powder. Just sayin…..The op rod can be rebuilt which might be a good way to go. Op Rods are getting harder to find and when you find one a premium price is required so it seems. Garands require grease. I’m not sure if you are aware of this. If you are, please no offence taken.
Garand Blowup with old US ammunition.

http://www.socnet.com/showthread.php?p=1344088

There was a thread on another forum titeled “What’s in your ammo can” and
Quote:
many guys had old surpluss ammo so I told this story. Ty (arizonaguide) asked that I come put it here also so here it is boys, draw your own conclutions.

Back in the mid 80s my Dad and a bunch of us went shooting in Arizona. Dad had a couple thousand rounds of WWII surplus .30M1 (30-06) ammo that looked great on the outside cut his M1 in half in his hands. He was kneeling with elbow on knee when the first round of this ammo went BOOM! We were all pelted with sand and M1 shrapnel.

When the dust cleared Dad was rolling around on his back with buttstock in one hand, for stock in the other, barrel and receiver hanging by the sling around his arm trying to yell “mortar” thinking he was back on Okinawa in battle. The blast had removed his ear muffs, hat, glasses, and broke the headlight in my truck 15 feet away but Dad was only shook up and scratched a bit once he got his wits back. It sheared off the bolt lugs, blew open the receiver front ring, pushed all the guts out the bottom of the magazine, and turned the middle of the stock to splinters.

After a couple hours of picking up M1 shrapnel we headed to the loading bench and started pulling bullets. Some of the powder was fine, some was stuck together in clumps, and some had to be dug out with a stick. It didn’t smell and was not dusty like powder usuley is when it’s gone bad. Put it in a pie tin and light it and it seemed a tad fast but not so you would think it could do that, wasent like lighting a pistol powder even. He had 2000 rounds of this stuff and nun of us were in any mood to play with it much after what we watched so it all went onto a very entertaining desert bon fire. I got the M1 splinters when Dad died last year and will post pix here below for your parousal and entertainment.

Anyway, I no longer play with any ammo I am not 100% sure has always been stored properly . . . cheap shooting ain’t worth the risk to me anymore! I still buy surpluss if the price in right but I unload and reload it with powder I am sure of or just use the brass.

She was a good shooting servasable Winchester M1 before this.












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Old February 7, 2013, 10:26 AM   #20
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For a time Pakistani 303 got a bad reputation on the web due to blowups being reported. I highly suspect it was simply due to old ammunition and the pressure spikes that happen, but without the ammunition to examine, or people looking for evidence of age, all we know, is the accident.

http://1919a4.com/showthread.php?174...humb-*graphic*




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Old February 7, 2013, 10:30 AM   #21
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I get attacked all the time from people who are in a state of denial that their "lifetime" purchase of cheap surplus ammunition or gunpowder might be less than they thought it was.

The facts are that ammunition and gunpowder does not get better with age and there are risks with using the stuff.

Those risks are hard to quantify, but they are there.
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Old February 7, 2013, 08:58 PM   #22
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So I'm seeing that old ammo is not as stable as old powder. Perhaps has something to do with the powder in ammo being in brass? Or perhaps the priming compound affects it over time? Interesting.
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Old February 7, 2013, 11:11 PM   #23
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If the powder smells like a burnt out muffler bearing, just use it for plinking ammo.
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Old February 8, 2013, 09:25 AM   #24
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The staffers ought to make a "sticky" out of those pics from Slamfire, and put them in the beginning handloading section. Just maybe they will read more about this sexy art of handloading,,,, not that it had anything to do with handloading.
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Old February 8, 2013, 02:31 PM   #25
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Quote:
So I'm seeing that old ammo is not as stable as old powder. Perhaps has something to do with the powder in ammo being in brass? Or perhaps the priming compound affects it over time? Interesting

Maybe I have confused people.

Gunpowder is an unstable high energy molecule that is breaking down from the moment it is made. Heat accelerates the breakdown. As gunpowder deteriorates it gives off NOx. This NOx attacks nitrocellulose accelerating the deterioration process. Gunpowder has stabilizers to soak up the NOx but at some point, they are consumed. When gunpowder breaks down it produces heat. When the stabilizers are depleted and the reduction-oxidation process starts ramping up, gunpowder can produce enough heat to self ignite. All it takes is a tiny spot to be hot enough and the whole pile burns.

Big piles of old gunpowder have the potential to catch fire. Their surface also becomes sensitized which means that friction alone can cause it to ignite. I believe this explains the turret explosion in the Iowa. They were using old WW2 era powder that had been stored in hot conditions for years and was fuming as it was being rammed.

As gunpowder breaks down, producing NOx, the powder grain deteriorates and it deteriorates unevenly. At the same time some of the NOx reacts with water vapor (always in the air) to become nitric acid gas. Nitric acid attacks brass, it weakens brass, it also causes corrosion. I don’t know if the bitter smell is from NOx or nitric acid gas, probably from NOx as it is a series of compounds.

So with old powder you have this uneven powder grain that will not burn in a consistent manner. I was told it causes “burn rate instability”, the gist of which is that you don’t get a smooth pressure curve. If the burn is uneven, pressure waves can get out of sync with each other and that will cause pressure spikes. Given that the cases have been weaken by nitric acid gas, high pressure and weak cases are a bad combination.

If the powder physically breaks down, to a dust, the surface area is vastly increased, and the initial burn rate will be high.

If the powder is double based, nitroglycerine attacks the nitrocellulose, increasing the rate of deterioration. This is why double based powders have a shorter shelf life than single based. Nitroglycerine will also migrate to the surface of the powder grain, because water molecules, condensing and evaporating in the air, wick the stuff to the surface. A nitroglycerine rich surface will change the burn rate, actually spiking the pressures.


I don’t know that much about primer deterioration. Primers compounds are tested to be compatible with gunpowder. The old chlorate primers used to dud out over time. From what I have read heat will dud out styphnate primers, but I don’t have a good idea for the shelf life of lead styphnate primers.
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