I wasn't aware gunpowder could 'auto combust,' it was my understanding it needed something even as simple as a static charge to set it off. Interesting...
Smokeless powders came out in the 1880's and very soon the powers that be found out that nitrocellulose propellants would auto combust. That was over 140 years ago, and the shooting community has 140 years of ignoring this problem and 140 years of education to become current. How do you point out a danger to someone who does not want to hear it?
A number of times I have mentioned the term,
Agnotology, which is the study of culturally induced ignorance. Industry has no reason to educate the shooting society about the dangers of old, deteriorated gunpowder. And then, the shooting society does not want to hear about it, as it conflicts with their bias that they and their gunpowder are immortal. From industries viewpoint, this is a win-win. If the shooting society knew that everything about old gunpowder is bad, then the shooting community might want things like "best buy" dates on ammunition and powder containers. And if the best buy date was five years ago, who would pay full price?. In all respects, an ill informed society making irrational choices is just wonderful to sellers. So what you read, what you consume, is all geared on educating you on what to buy, and nothing about what not to buy.
And it works!
Anyway, searches will find the information:
Ammunition Surveillance Procedures SB 742-1
Chapter 13 Propellant and Propelling Charges
page 13-1
WARNING
Nitrocellulose-based propellant can become thermally unstable as the age. The normal aging process of the propellants involves deterioration of the nitrocellulose with an accompanying generation of heat. At some point, the propellant may reach a state where heat is generated faster than it can be dissipated. The accumulation of heat can lead to combustion (auto ignition). Chemical stabilizers are added to propellants to slow the aging process. In time, the stabilizer levels will drop to a point where the remaining effective stabilizer (RES) is not sufficient to prevent an accelerating rate of decomposition. When this point is reached, the propellant may auto ignite, with possible catastrophic results to property and life. Monitoring the stability level of each propellant lot is essential for continued safe storage.
Page 13-5 , Table 13.2 Propellant Stability Codes.
Stability Category A 0.30 or more Percent Effective Stabilizer
Acceptable stabilizer loss: safe for continued storage
C 0.29-0.20 Percent Effective Stabilizer
Significant stabilizer loss. Lot does not represent an immediate hazard, but is approaching a potentially hazardous stability condition. Loss of stabilizer does adversely affect function in an uploaded configuration. Disposition instructions will be furnished by NAR. All stability category “C” assessment on the installation must be reported in writing…
One year after becoming stability category “C” a sample of the bulk propellant lot or the bulk-packed component lot will be retested. If the lot has not deteriorated to category “D”, it will be retested each year until it has been expended, or it has deteriorated to category “D”, at which point it will be demilitarized within 60 days.
D Less than 0.20 Percent Effective Stabilizer
Unacceptable stabilizer loss. Lots identified as stability category “D” present a potential safety hazard and are unsafe for continued storage as bulk, bulk-packed components , or as separate loading propellant chargers. Bulk propellant, bulk –packed components and separate loading propelling charges will be demilitarized within 60 days after notification of category “D” status.
Propellant Management Guide
http://www.fas.org/man/dod-101/sys/land/docs/prop_guide.pdf
DEFINITION:STABILIZERS
Stabilizers are chemical ingredients added to propellant to prevent auto ignition during the propellant's expected useful life....
EXPLANATION:As nitrate ester-based propellants decompose, they release nitrogen oxides. If the nitrogen oxides are left free to react in the propellant, they can react with the nitrate ester, causing further decomposition and additional release of nitrogen oxides. The reaction between the nitrate ester and the nitrogen oxides is exothermic, i.e. the reaction produces heat. The exothermic nature of the reaction creates a problem if sufficient heat is generated to initiate combustion. Chemical additives, referred to as stabilizers, are added to propellant formulations to react with free nitrogen oxides to prevent their attack on the nitrate esters in the propellant. The stabilizers are scavengers that act rather like sponges, and once they become saturated they are no longer able to remove nitrogen oxides from the propellant. At this point self-heating of the propellant can occur unabated. Once begun, the self-heating may become sufficient to cause auto ignition.
Everything about old gunpowder is bad, there is nothing good about old gunpowder. It will blow up your gun, it will, in bulk, auto combust. The amount of bulk is a minor article of contention in the Insensitive Munitions community. Some hold to a 4 inch rule, that is shells less than four inches in diameter won't auto combust due to the thermal conductivity of the shell. The mass of the metal is proposed to keep powder temperatures down due to thermal heat conduction. The Insensitive Munitions expert I met, claimed this was bunk and he had investigated enough explosive incidents to reach that conclusion. There may be something to it, when I was indoctrinated by industry dis information on this topic, I pulled a number of bullets from 1898 manufactured Krag ammunition and examined the powder. One, the powder was beautiful, it had tiny points of ruby light. I examined the powder with a magnifying glass and saw tiny ruby granules that looked like charcoal briquets in flame. I remember seeing what had to be the waving of flames, just exactly as burning coals give off. I had no idea what I was looking at. And I remember thinking what I was seeing was inexplicable, as I knew gunpowder was immortal. That is what I learned in the popular press. I wish I had taken a picture, because I have never seen this again, and don't blame anyone for calling me a liar. I don't understand why the propellant did not go "poof" in front of my face.
I gave most of those cartridges away but I kept a couple, but none of them showed that level of deterioration. All of them had red gunpowder, I used to post the picture to show that the gunpowder was deteriorated, but deniers claimed original 1898 gunpowder was red, when new, and I don't have any color pictures from 1898 to prove otherwise. So I stopped posting the picture. Nothing you can show will ever convince a denier. They will come up with some very imaginative false explanations.
But, to get back on topic, maybe gunpowder will not auto combust in small arms cases, it sure as hell will in one pound and five pound containers. And I have found accounts of powder fires. Which, deniers all explain away.
For a time I was following the Camp Minden explosions. This was a demilling facility and huge explosions were going on. I believe old deteriorated propellants were combusting, but, it could be workers tossing cigarette butts. After all, none of them want to continue living. So what do I know? My advice, you don't want one of things in your neighborhood, nothing closer than 90 miles away.!
New Information: Bunker blast at Camp Minden
By USAHM-News on October 19, 2012
https://usahitman.com/nibbacm/
6 arrested in Camp Minden explosives investigation
http://www.fox8live.com/story/22637088/la-company-managers-indicted-in-explosives-case
Camp Minden: From blast to possible burn
http://www.ktbs.com/story/28065933/camp-minden-from-blast-to-possible-burn
side note. All that surplus ammunition on the market was tested, and by the criteria in their manuals, it was determined to be unsafe to keep in storage, and unsafe to issue to their troops, by the originating agency. And you, silly you, come by and think it is day old bread because it has not hurt you, yet.
Old Powder Caused Fire!
http://www.thehighroad.org/showthread.php?t=788841
First, sorry for the long post. Second, if I didn't know the people this happened to I would have a hard time believing this, I'd probably call this BS. I hunt at a property owned by someone I used to work with. All I have is his email address. I have been trying to contact him for several weeks via email. He lives over an hour a way and I hadn't tried to catch him at home yet. I finally got hold of him the other day. He apologized for not getting back to me sooner, but he had a house fire and had been dealing with that since the beginning of the month.
I drove there today. There was a trailer set up for his family to live in while the house gets restored. His wife was there when I got there. I asked her what happened. I couldn't believe her answer. Apparently my friends brother gave him about 15 pounds of gun powder for reloading about 10-15 years ago. It never got used. Sorry, I don't know what kind of powder it was. Their daughter just got out of the shower in the room next to where this powder was stored. She heard a WOOOOSH sound and came out of the bathroom to find the place in flames. It started where the old powder was stored.
Luckily, they were able to keep the fire down for a few minutes with an extinguisher and the fire dept responded in about 5, but there was some serious damage. I saw the spot where the powder was kept and the floor all around it charred, the rest of the place sustained heat and smoke damage. They were lucky they were home and someone got on this almost immediately or the place would have been a total loss. The BIL had some more of this powder at his home, he dumped it outside and lit it off. I'm sure he didn't know it would have made good fertilizer.
There was no other suspected cause of this fire than spontaneous combustion of this old gun powder. Has anyone heard of old un-stable gun powder just going up like this? I've got probably 20 pounds of powder in the next room and I'm sure many of you have more than that. After hearing this, I'm going to make sure it all gets used or at least smelled now and again if it sits for a few years. Green grass beats a burned home! 
I hijacked someone else's thread and, expectedly I suppose, I did not receive the answers I desired. 
