red rust in powder


July 14, 2009, 11:05 PM
Found my first can of powder (IMR 4198) with rust in the powder. Kind of hangs in the air. New can from 1994 or so. Will dispose tomorrow, but I wonder if anyone ever found out what causes this, as the can seems to have rusted in the inside. Have a can of the same powder that is ten years older and is shiny on the inside. (only use this for reduced loads and 150 grain 30-30.)

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July 14, 2009, 11:43 PM
Sounds like the powder has gone bad. Is the powder rust colored? Or is it just the can? Does it smell bad also?

July 15, 2009, 12:16 AM
Powder looks good, typical ether odor.

July 15, 2009, 12:23 AM
Hi Jim,
yes, if the powder is "rusty" it needs to be destroyed.
I don't know chemistry well enough, but powder manufacturers use various chemical additives including calcium carbonate to stop the decomposition of nitrocellulous. Over long periods, nitrocellolose forms acids - and that's the most likely cause of your rusty dust!
I don't understand why some does and some doesn't...

Graphite is also used to coat the granuals to control the burn rate and minimise static buildup.
So when you destroy the powder - don't follow the old advice of using it as fertiliser in your garden. It could take 10+ years to break down.
I've experimented with doing just that - leaving a small pile im my garden for three years - it went up when I lit it!

Pour it into small lines and burn it safely.


July 15, 2009, 12:58 AM
Yeah, I don't believe the fertilizer bit either. Burning maybe safest way, but I'll bet if you asked the EPA or DNR you won't get a straight answer. Thanks for the replys, guys.

faire bien de...!
July 15, 2009, 01:29 AM
A couple years ago a friend gave me a can of IMR-4227 and from the code printed on it, I think it's from 1977. I had never used that powder before, so I looked into what I could use it for. The best thing I came up with for myself was reduced loads in 30-06 with some lead bullets I bought. When I went to the range I was very pleased with the results, plus my tired '03 was happy to not have to work as hard. I was superised how fun and how accurate shooting those lead bullets could be with that powder. Anyhow, I was reading something sometime after about a reddish dust in old powder cans being rust and to not use it. Well, that IMR-4227 I was given was full of red dust! It had not crossed my mind that it was rust, I just thought it was some type of burn rate inhibiter or something. When I took a closer look inside the can, it sure enough was from the inside deteriorating. But, I guess my point is that the stuff shoots fine as far as I can tell and I've almost used the can up. It could be that it burns a bit slower with that dusty coating on it, so when I get a new can I'll start over with a lesser charge, and of course I wouldn't be firing that stuff in a new match gun or one that wasn't already somewhat worn out. My experience could also be that the stuff I have dosen't have "that" much rust in it to make a real differance, but if I had known it was rust before I fired it, I may not have at all.

July 15, 2009, 01:40 AM
Try dumping it in a glass or stainless mixing bowl and swirling it around with a strong magnet. You might be able to remove the rust and save the powder.

Don't try this with a plastic bowl or you'll have to buy the missus a new one because of the graphite stains.:uhoh:

on edit: This suggestion is assuming you are sure the powder is okay and only needs the rust filtered out. If the powder smells acrid or if the granuals don't look right the powder should be tossed.

July 15, 2009, 02:47 PM
Your red powder is outgassing nitric acid gas. The acid gas is removing the lining from your can.

Single based powders are made of nitrocellulose. Nitrocellulose decomposes to a lower energy molecule, releasing nitric acid gas. Nitroglycerine accelerates this decomposition, which is why the Army scraps double based powders at 20 years, 45 years for single base.

These dates are based on risk. Powders go bad before and after these shelf life dates. I have some IMR 4064 powder that I bought new in Jan 1990. It has been stored in cool dry conditions. Little, rice kernel sized tarnish spots were all over the inside of the can. The old ether smell was gone. I am loading that powder up and going to be shooting it soon because it is on the way out.

Your powder is on its last legs. The stuff will shoot, but it will also ruin cases. The nitric acid gas will cause green corrosion on bullets and create case neck cracks. I had to toss 700 LC match because the deteriorating surplus powder ruined the cases. Incidentally, the rate of the reduction/oxidation reaction increases over time.

Deterioration may cause weird pressure curve shifts. As the powder chemistry changes through deterioration, the burn rate will change. For double based powders, the surface becomes NG rich, and the initial burn rate increases, even though the overall energy content of the powder is less. Which means you can have a pressure spike even though the exit velocity of the bullet is not abnormal.

I am lacking information on single base powders, the Insensitive Munitions guy that I am learning from, he is not available. But based on my experience, I think the same issues happen in single base.

I have shot deteriorated IMR 4895 and IMR 3031. The can from which the IMR3031 came from, when I poured the stuff into a measure, a cloud of red particles floated in the air! (I suspect only some of it was rust) The stuff shot well but I have had muzzle blasts of different sound/intensities. And I have had stiff bolt lifts with charges that were grains from maximum. Something is going on, and it is not good.

There are people out there how believe the shelf life of gunpowder is infinite. This is not true.

The Bushmaster
July 15, 2009, 03:02 PM
WHAT?!!? BURN IT? YOU WANT TO HAVE TO PAY FOR "CARBON OFFSET? Let your grass have it. Even if you don't believe that the nitrate in the powder isn't good for your yard. At least it's not bad for it either...

July 15, 2009, 03:18 PM
Your red powder is outgassing nitric acid gas. The acid gas is removing the lining from your can.+1
Normal good powder will not rust the inside of a powder can.

It has or is going south.

Dump it.


July 15, 2009, 03:21 PM
I ran the powder "stir in the bowl with a magnet" thing by my better half, she was not impressed and would probably dispose of the powder in a place not to my liking. I had thought about this rust awhile, and concluded that for the rust to be there in the first place, bad things were going on. I am not in particular love with this powder anyway, it's gone.

July 15, 2009, 03:41 PM
Had a good laugh at Sport45's sulution to rusty powder. What a great sense of humor he has, I though, and added his "cure" to my list of shooting jokes to tell my pals. Then it occured to me that he might have actually been serious and now I'm a bit worried. Tell us Sport45, you really were kidding weren't you?

Bush Pilot
July 15, 2009, 05:56 PM
I had the same thing happen to me a couple of years ago, it made a nice quick "poof" when I set it on fire. It isn't worth trying to salvage.

July 15, 2009, 10:08 PM
No, I've actually done that to salvage a few ounces of powder from one 8# can to mix with nearly full can that hadn't started rusting (same lot). I stored what was left in a clean antifreeze jug that I properly labled. In Houston everything rusts, I've even seen rust on the inside of camp fuel cans. The powder did not have a bad smell or appearance and it wasn't anywhere near 20 years old. Just rust from inside the can.

That was quite a while ago. The ruined plastic mixing bowl is different story....

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