I'm wondering if anybody else has experienced this. A couple of years ago I developed a load with N150, PPU brass and the Prvi 285 grain 9.3 bullet. All seemed well at the time and I kept 20 rounds loaded in a box. Room temp, no garage or attic storage, etc. Anyway I was,shooting the rifle the other day and noticed that several of the primers seemed unusually flat. I know this is an imperfect measure but usually indicates increased pressure. Accuracy was fine btw.

Anyway after the shooting session I decided to pull down the remaining rounds. What I found was that the bullet bases were covered with grayish powdery corrosion, and the powder didn't dump smoothly from the case. There were a couple of clumps and much powder remained stuck to the case walls. Some of that came out by tapping the case but some required swiping with a q-tip to get out.

So I would conclude that somehow the powder in the case had deteriorated over the two years it sat loaded. Anybody else notice this hsppening? I do recall reading somewhere that n140 and N150 have been known to deteriorate. Anyway I fertilized the lawn with the dumped powder and the couple of ounces remaining in the jug. I did not notice any acid smell coming from the jug, but it didn't have that fresh solvent smell either. I opened another 2 lb jug and,was greeted with the familiar ether smell. Both jugs date from the late 1990's if that helps any.

Can't figure out how to upload pics but here's a link to,a shot of the bullet bases..

http://s1083.photobucket.com/u....jpg.html?sort=3&o=0

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Both jugs date from the late 1990's if that helps any.

All gunpowder deteriorates. Gunpowder is either nitrocellulose, mixed in with a lot of chemicals, or nitrocellulose and nitroglycerine, mixed in with a lot of chemicals. I have been ranting and raving for a number of years on gunpowder deterioration, primarily because the shooting community does not want to believe this, has been told otherwise in gun magazines, but, ignoring what the shooting community desires, gunpowder follows the second law of thermodynamics. It is a high energy compound that is breaking down to a low energy compound.

It is probably confirmation bias, but it seems that I am reading more and more reports of Vihtavuori gunpowders breaking down. It does seem interesting that their lifetime is getting close to 25 years, which is beyond the reasonable shelf life for double based, but not beyond the shelf life of single based powders: 45 years. All the Vihtavuori stories I have found deal with single based powders. Which shows that the lifetime of gunpowders is rather unpredictable.

When gunpowders break down they release nitric acid gas. Nitric acid gas will corrode copper and brass. Probably a lot more things as nitric acid is very reactive. These bullets were pulled from very old US surplus ammunition, I don't remember how old.

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Anyway after the shooting session I decided to pull down the remaining rounds. What I found was that the bullet bases were covered with grayish powdery corrosion, and the powder didn't dump smoothly from the case. There were a couple of clumps and much powder remained stuck to the case walls. Some of that came out by tapping the case but some required swiping with a q-tip to get out.

These are 1960's factory Norma ammunition that went bad in the case. The guy who posted this, these cartridges had been stored in his father's house, if I remember right. The corrosion is due to nitric acid gas.

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Anyway I was,shooting the rifle the other day and noticed that several of the primers seemed unusually flat. I know this is an imperfect measure but usually indicates increased pressure. Accuracy was fine btw.

Lucky you, the stuff did not blowup your rifle. Old gunpowder has, and will, blow up firearms What happens is a phenomena called burn rate instability. It is a catch all term. Gunpowder has been engineered for a consistent burn. The shape, the geometry are all carefully engineered into the final product. When gunpowder deteriorates, it deteriorates unevenly. The grain changes shape, instead of a nice smooth tube, (for example) now the tube is thinner in places. When it burns, the pressure is inconsistent because parts of the tube are burning faster, other slower. These pressure waves conflict. If there is dust in there, the surface area is huge. If it is a double based powder, the nitroglycerine wicks its way to the surface, which will spike the pressure curve.

I have a number of accounts of military surplus ammunition blowing up rifles. The owners and the commentators don't know, and don't want to know about old ammunition and pressure problems, so the suggested reasons why the gun blew up can be quite fantastical. Often racist.


Here are some other threads, the first one has great pictures of the effects of deterioration.

Has anyone else had Vihtavuori N140 corrode in loaded ammo?

http://www.falfiles.com/forums...thread.php?p=3745264


Bad N140

http://thefiringline.com/forum...old+gunpowder&page=3

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Of particular interest to me was the link to the thread on N140. In the early 1990's, my dad got a 1/4 lb free sample container of N140 at Camp Perry, and gave half of it to me. That's about 20 rounds worth in .308; not enough to do serious load development with. I put it in a plastic bottle with a plated and painted steel cap with cardboard seal disc. I left it at the back of a high shelf in the basement where it was out of sight and soon out of mind. Some time later I bought a full pound of N140 to experiment with, but that original 1/4 lb continued to sit.

I finally re-encountered the bottle during some cleaning out activity. It looked like this:

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the lid out. Rinse water put over it poured out yellow. At that point I cut the container open and buried the wet mass under the compost heap to let nature take its course.

Interestingly, the remaining 1/8 lb still at my father's place (also untouched) appeared to be in fine condition in it's original container. Shaking some out onto a white sheet of paper to look for traces of red dust showed no signs of any. Odor was normal. Nonetheless, with only that small amount left, we scattered it over the yard.The powder in it was not powder any longer. The grains were all stuck together. That was the result of the lid seal failing and letting humidity in. The acid fumes corroded

The final lesson, is that old gunpowder will burn your house down. If you ever see a jug gunpowder outgassing like this, get it out of the house and dispose of it.:

Vihtavuori N150 gone bad

http://m14forum.com/ammunition...i-n150-gone-bad.html

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Well I was going to work up a load today with Vihtavuori N150, but when I opened the jug, whew, what an odor!!! Then gold colored fumes started coming out of the jug. Don't know how old this jug is, it was given to me about a year ago.

Tried to get a good picture of the fumes, but the wind kept blowing it around.

Anyways, keep an eye on your powder.

When gunpowder deteriorates, it heats up. In quantity, definitely eight pound jug size, maybe one pound jug size, the stuff will catch on fire. Gunpowder in small arms cases is hard to auto combust because the shell casing draws out heat. The US Army believes that nothing smaller than a five inch shell will auto combust, due to the cartridge walls drawing out the heat, but an Insensitive Munitions Expert I met, said that was all bunk.

On forums you will run into crazy coots who have been hoarding gunpowder. They store the stuff in the house, and one day, their hoard of WW2 gunpowder will catch on fire, and burn them alive in their sleep.





The coots don't believe this, and in fact, as you will find, the shooting community does not want to believe this. In the future see the reaction of people when you tell them you think your gunpowder went bad, due to age. They won't believe you. Shooters only believe what they want to believe, and they want to believe that their stash of gunpowder and ammunition will last forever.

You have pictures? I could use pictures, if you have them, please post them and allow me to copy.

Slamfire: Yeah I'm a believer now. There's a link to my photobucket account with a pic of the bullet bases and corrosion. Can't figure how to load it directly to this site though. If you can get it in hand you're welcome to copy and use it. If all else fails, it's on my phone and I could send it to you in a text message...

I agree that this is a very probable safety issue which is why i posted it, and although it seems to go against "ccurrent wisdom" it's likely more widespread than most folks know.

Piece of cake to post pictures. Copy the IMG link and paste it in the message.

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I agree that this is a very probable safety issue which is why i posted it, and although it seems to go against "ccurrent wisdom" it's likely more widespread than most folks know.

Just looked at the definition of Confirmation Bias in the book, "You are not so Smart"

The Misconception: Your opinions are the result of years of rational, objective analysis.

The Truth: Your opinions are the result of years of paying attention to information that confirmed what you believed,while ignoring information that challenged your preconceived notions.

This is what is most likely going on with "common wisdom". Reloaders want their ammunition and gunpowder to last forever, so they ignore any evidence otherwise. If you search this site, you will find posts, about gunpowder lifetime, that obey Confirmation Bias. I have answered, or began ranting and raving within a thread, about ammunition lifetime, put much more information in my post, and subsequent threads just ignore all the information. You will read posters discussing their pre WW2 gunpowders they have, or used, or bragging about the massive quantities of old gunpowder they have, and that proves to them that gunpowder lasts forever.

Thanks for the links. Some pretty gross looking stuff there. It all looks like maybe 20 to 25 year old powder. I still see the confirmation bias by people asking if the poster is SURE the powder didn't get damp or overheated. And another poster claiming that it did and thinking that was the probable cause of the deterioration. In my case it is neither. It was kept in a dry basement never getting hotter than 62 degrees nor cooler than about 55.

And I see that these reports deal mainly with Vihta Vuori although you have examples with other powder too. I'm going to guess that this deterioration has to be somewhat condition dependent though. The jug I used that showed the deterioration had been open for a few years although tightly capped. While the other jug of the same age gave off ether odor when the factory seal was broken. I'm going to assume that that one is ok to use and will probably last for a good while without deteriorating. But I guess time will tell. Would be interesting to accumulate data on other types and brands as well. I would expect that,some of the chemistry and physical properties differ enough to give different results. And didn't I read once that Hercules had kept a quantity of Unique stored sealed under water for over 100 years with no change in performance? Maybe that is partly responsible for the indestructability myth getting started.

This sort of information I believe could stand some wider dissemination. Over the past several years, "hoarding " seems to have gained in popularity again and it will be important to know the shelf lives of components and loaded ammo. Maybe pulling down a round or two every so often will be a good check on how a particular lot of ammo is storing.... I think I got really lucky with my small incident. The ammo had only been loaded for two years and from the looks of things the deterioration had just gotten started. It was serious enough of course but hadn't become disastrous.

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Originally posted by H47:
In my case it is neither. It was kept in a dry basement never getting hotter than 62 degrees nor cooler than about 55.

And I see that these reports deal mainly with Vihta Vuori although you have examples with other powder too. I'm going to guess that this deterioration has to be somewhat condition dependent though.

These are my bullets, pulled from 308 ammunition that had been loaded 2 to 3 years. The powder is AA4064, stuff I bought new in the mid nineties and the powder has been stored in the house. I was having pressure problems, pulled the bullets and noticed the corrosion pattern. The powder in the jug has a neutral smell. It is going bad.

This is from military surplus AA2520, which I bought prior to the 2000. I did not know that military surplus powder was dumped because the military had determined that it was past a safe shelf life. Cases loaded with this stuff lost case necks after firing. Darn stuff caused lots of malfunctions in my Garand. It took a brass brush and a cleaning rod to get the neck out of the chamber.

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And didn't I read once that Hercules had kept a quantity of Unique stored sealed under water for over 100 years with no change in performance? Maybe that is partly responsible for the indestructability myth getting started.

They test the stuff after drying. They don't leave it out to see how it reacts to aging outside of the water. I was told water hurts shelf life, dissolves some of the gel. Water would dissolve any nitric acid gas and keep the powder cool. I understand old Naval gunpowder was kept in pools till recycled.

I am of the opinion that it is not in the economic interest of the industry to educate reloaders about gunpower or ammunition aging. Our ignorance is their strength. They don't want us being picky about what we buy. If we buy unquestioningly, if we buy anything they put in front of us, they make more profit. A certain sector of the community likes old. Wants to shoot the same ammunition Grandfather used in the battle of the Bulge. It is in no one's financial interest to educate these types about the dangers of old ammunition.

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This sort of information I believe could stand some wider dissemination. Over the past several years, "hoarding " seems to have gained in popularity again and it will be important to know the shelf lives of components and loaded ammo. Maybe pulling down a round or two every so often will be a good check on how a particular lot of ammo is storing.... I think I got really lucky with my small incident. The ammo had only been loaded for two years and from the looks of things the deterioration had just gotten started. It was serious enough of course but hadn't become disastrous.

Information, knowledge is important. But the community does not want to know. Not really.

Well I detect a note of honestly acquired cynicism. I can believe that a lot of folks are reluctant to accept that which goes against what they believe for one reason or another. But we do need to be paying attention to such things. If for no other reason than our own well being. So thank you. I know that I benefitted from your info.