I've recently noticed some RUSTY-COLORED DUST in two of my IMR metal powder cannisters - IMR4831 and IMR4350. The powder smells "normal," and the powders shoot OK. What is it?

I don't know for sure what causes it but the rusty color indicates oxidation usually cause by humidity and exposure to the air. I have 10 lbs of IMR-4831 that is the same. Its old but appears normal, smells normal but leaves a dusty rust colored residue on the powder funnel and powder thrower after many charges have gone threw it. I'm still using this powder and it works fine but before you do, assume the burning rate may have changed slightly because of the oxidation of the powder work up your loads starting fairly low. Take it out of the metal cans and put it in plastic. Use it up soon if you feel comfortable using it. If it is really dusty and the residue is quit prominant only after a few charges through the funnel chuck it in the garden. I'm not endorsing the use of this powder as I cannot see the amount of degradation. It may be unsafe.

AI, I experienced the rust dust in one can of IMR4198. Another can I bought at the same time did not have the same dust (see thread on canister powder residue I4198). I just got rid of the one with the dust. The rifle is worth much more than the cost of more powder.

Could be two things. First, rust from the can.
If you have jsut a little and the powder smells of solvent (ether) it is probably rust.

Second, decomposition products. If the powder smells like ether you are probably ok. IF you open the lid and a red vaporous haze comes out you have a problem. The odor will be nasty. The red fog is notrous oxide. At this point the powder will have lots of red powder in it. It is bad and you should flush or spread it on the lawn. I may catch fire spontanioulsy in your cupboard so, it is best to just toss it.

This following is posted by IMR/Hodgdon powder:

How to Check Smokeless Powder for Deterioration
Although modern smokeless powders are basically free from deterioration under proper storage conditions, safe practices require a recognition of the signs of deterioration and its possible effects.

Powder deterioration can be checked by opening the cap on the container and smelling the contents. Powder undergoing deterioration has an irritating acidic odor. (Don't confuse this with common solvent odors such as alcohol, ether and acetone.)

Check to make certain that powder is not exposed to extreme heat as this may cause deterioration. Such exposure produces an acidity which accelerates further reaction and has been known, because of the heat generated by the reaction, to cause spontaneous combustion.

They don't mention a rusty colored dust.

Did you see this particular thread from last week?https://forums.accuratereloading.com/eve/forums/a/tpc/f/2511043/m/485105532

quote:

Originally posted by Ackley Improved User:
I've recently noticed some RUSTY-COLORED DUST in two of my IMR metal powder cannisters - IMR4831 and IMR4350. The powder smells "normal," and the powders shoot OK. What is it?

Depends! It often indicates that your powder is breaking down, and should be discarded! However, breakdown is usually accompanied by a marked change in odor from the "ether' smell of good powder.

It is conceivable that your powder cans have some rust inside which is giving the red-colored dust. When powder breaks down, there are also some of the grains that change color to a red or dusty light-brown color, and begin to disintegrate. If you dump a good-sized sample of the powder into a bowl for inspection, you can usually pretty much tell if the powder is disintegrating. If it is, use the rest of it to fertilize your lawn!

IMPORTANT WARNING!!!

I called a IMR/Hodgdon ballistic engineer. He said, "THE RUST-COLORED STUFF INDICATES THE POWDER IS GOING BAD [DETERIORATING]. IT WILL EVENTUALLY SELF IGNITE. Get rid of it ASAP!" I don't need a fire or explosion, I'm getting rid of it immediately!

Also, he said get rid of any ammo loaded with it, because the acid deterioration products will fuse the bullet to the case causing chamber obstruction. TAKE DOWN YOUR AMMO LOADED WITH IT!

HE SAID THEY EXPECT POWDER TO STORE 5 YEARS, ANYTHING BEYOND THAT IS GRAVEY. CHECK YOUR OLD POWDERS.

quote:

Originally posted by Ackley Improved User:
IMPORTANT WARNING!!!

I called a IMR/Hodgdon ballistic engineer. He said, "THE RUST-COLORED STUFF INDICATES THE POWDER IS GOING BAD [DETERIORATING]. IT WILL EVENTUALLY SELF IGNITE. Get rid of it ASAP!" I don't need a fire or explosion, I'm getting rid of it immediately!

Also, he said get rid of any ammo loaded with it, because the acid deterioration products will fuse the bullet to the case causing chamber obstruction. TAKE DOWN YOUR AMMO LOADED WITH IT!

HE SAID THEY EXPECT POWDER TO STORE 5 YEARS, ANYTHING BEYOND THAT IS GRAVEY. CHECK YOUR OLD POWDERS.

I'd love to see someone say that directly from Hodgdon.....posted in such a way that we know it authentic.....I say this as I've had powder stored for nearly 40 years that still shot well.

rust = red colour
rust = oxidation
spontaneous combustion =rapid oxidation=fire
It may be safe it may not. Why take a chance?

Vapodog, call IMR/Hodgdon yourself. Ask if powder showing signs of deterioration is safe to keep around - including the rounds reloaded it with (call 913-362-9455). Some powder does last a long time, but some powder deteriorates - that which is deteriorating is not safe. It's your life and home.

So the next qusetion is how do you folks dispose of old powder? I throw old powder on my lawn. It acts as a mild fertilizer.

quote:

Originally posted by dick broussard:
So the next qusetion is how do you folks dispose of old powder? I throw old powder on my lawn. It acts as a mild fertilizer.

I like to sprinkle it on the lawn during a light rain.... but it is not neccessary to wait for rain..... Do you get rain in Texas?

I don't believe IMR/Hodgdon said you had to get rid of old powder, just because it's old. They advised getting rid of powder showing signs of deterioration (i.e., acrid smell and/or rusty-colored dust) - young or old (although powder over 5 years old was more likely than new powder to show deterioration). IMR/Hodgdon recommended calling your local hazardous waste disposal people - whomever they may be. But, it seems easier to sprinkle the rotten stuff on the yard.

I have a very strange hobby of going around and buying up old cans of powder and when appropriate (the powder is good), test the powder using old data. When it is bad my nephew is delighted (no pun intended). Like I said it is strange but I have learned alot which I can share with you. First off, I have never seen a can of double base powder that was bad. It seems that double base powder is inherently stable due to the nitro incorporated. It may not have an infinite lifetime but it last longer than the average human. Having said that, if double base powder is heated above 100F than it will rapidly deteriorate (hours). Another point is that the older double base powders tended to have high nitro contents (20%) while some of todays double base have less nitro and do require a stabilizer.

Now single base powder is entirely different, it requires a stabilizer, which neutralizes the acids as nitrocellulose deteriorates. When the stabilizer is exhausted, the powder itself begins to be affected. The military has a program setup where they continually analyze the amount of stabilizer left and when it reaches the limit they get rid of it (think about that all you who buy surplus powder).

When the powder deteriorates, it lose strength, not increase as some say but this can be offset by the amount of moisture in the powder. I have seen the following characteristics in deteriorated powder: rusty grains, oily grains, greyish (like cigarette but). I have also seen metal cans that were rusty on the inside where the powder was good but I would speculate that powder was getting close to the point where the stabilizers were all used up. In general, observation of the grains themselves have been a guide to whether a powder was useable or not. Oh yes, I never load these at any where maximum loads...

Unique, do you agree then that the rusty-colored dust or residue is a sign of deteriorated powder as the IMR/Hodgdon technician indicated? My cannisters with this rusty residue smell like other cannisters of new IMR powder. The powder grains look normal. Finally, of the IMR line which are single-based and which double-based?

AIU. I believe all the IMR powders are single based. I think all the double based powders are made (imported) by Alliant.
Years ago, Du Pont made literally all the gunpowders in this country, both single and double based. Our illustrious government decided they had a monopoly, so Du Pont sold the rights to make double based powder to another company, I forget which. Then Hercules took over the manufacturing of the double based powders until Alliant bought them out.
Paul B.

Ackley Improved User:

Single base powder deteriorate over time with the amount of stabilizer and most importantly storage conditions affecting the rate of deterioration. This is probably true for double base but again the time seems to be much much longer. The question is how much deterioration are we talking about? My view is that if the grains are normal looking and the powder does not have an acidic odor than the powder is useable. As I stated earlier, if the grains themselves are rusty, oily or ash looking than I get rid of that powder.

Self-ignition is a bad thing but I would guess that really only happens when large quatities are stored and endothermic heat builds up. I just never heard of a single 1 lbs container going up because of deterioration. Anyone on this site ever experienced this?

I have many can of powder that show various levels of rusty residue and I am not a bit concerned about it. The grains look normal and shoot perfectly fine. Take a flashlight and look inside the can and see if the inside of the can is rusty. It probably is and shows up as spots on the inside of the can. This indicates that the grain particles are causing the rust. I would not load shells with the stuff and put them on the shelf for years but again I would have no problem loading shells and then going out and shooting them the next day. I never load maximum and always swab my bore afterwards. Waste not want not but safety first...

The military only keep their powder for 15 years regardless of the amount of stabilizer left so a suggestion that powder is only good for 5 year is a little silly. Also my research shows that Dupont IMR4831 had a very small percentage of nitro. Atleast it was classfied by the goverment's import/export documents as having nitro. This was not the case for the Hodgdon stuff and I do not know if it is still true for the IMR version. Anyway I consider all IMR Rifle powders as single base and capable of having a useful life of at least 20 years IF STORED PROPERLY.

unique,

Thanks for the enlightening posts.

Regards, AIU

The only powder that I have actually had go bad was WWII 4831 that had been stored in a garage in hot humid Central Texas. I bought the powder in about 1980 and it went bad about 1985. (This had been stored in the previous owners garage not mine) It produced a brownish, purple haze of dust and vapors when the container was opened. If you can manage to get a mild whiff of nitric acid odor you will recognise exactly what IMR powders smell like when they break down.
In the case of IMR powders the inside of the can will rust causing a brown powder. The old Hodgdon and Hercules cans had metal tops and bottom that would rust a few years after the can was opened. If you will notice first Hogdon, then Hercules and now IMR are all using plastic containers. That's right the old crummy rectangular IMR cans are about to be history.
You might save you old IMR cans for about 30 years and then sell them on Ebay as antiques.

quote:

Originally posted by ireload2:
The only powder that I have actually had go bad was WWII 4831 that had been stored in a garage in hot humid Central Texas. I bought the powder in about 1980 and it went bad about 1985. (This had been stored in the previous owners garage not mine) It produced a brownish, purple haze of dust and vapors when the container was opened. If you can manage to get a mild whiff of nitric acid odor you will recognise exactly what IMR powders smell like when they break down.
In the case of IMR powders the inside of the can will rust causing a brown powder. The old Hodgdon and Hercules cans had metal tops and bottom that would rust a few years after the can was opened. If you will notice first Hogdon, then Hercules and now IMR are all using plastic containers. That's right the old crummy rectangular IMR cans are about to be history.
You might save you old IMR cans for about 30 years and then sell them on Ebay as antiques.

I bought 8 pounds of old WWII surplus 4831 from Hodgdon in 1967 while living in Colorado Springs. Subsequently, this powder has "lived" in Indiana, Virginia, Texas, and New York. I now live in PA, and have a half-pound of it left(!!), and it still looks and smells OK.

Also have a few rounds of ammo left that I loaded with it over the years, and all ammo so loaded that I have recently tested still gives the original ballistics over the chrono.

In addition, I have chronographed G.I. Ball .45 ACP ammo that was headstamped "FA 18", made during WWI. It still averaged 820 FPS MV!

I believe that any smokeless powder that starts deteriorating in proper storage in as little as five years was faulty when it left the factory!

In reply to having powder go through spontainous combustion, I have witnessed it once. I went to a friends house one hot summer afternoon and saw his plastic garbage can melting from a fire within. He lives in town and it's illegal to burn within city limits, and doubly so in plastic cans . He told me, after the fire was extinguished, that a couple of hours before, he found an old can of powder going bad, so he just threw it away. I think the temp of the day had a lot to do with it's combustion.

I remember an old Hercules (Pre-Alliant) flyer that stated that a rusty colered "dust" in the powder indicated degradation of the propellant and that it should be discarded.

I recall Dupont (pre-IMR name change) saying the same thing.

AllanD

Clearly, using deteriorating powder is hazardous to reload and to store. Best to discard it and buy a new batch. Ask yourself - is it worth the minor savings to keep it and use it. For me, it's not.