Rusty Gunpowder

It's probably rust from inside the can. As powder deteriorates is flashes off chemicals that will oxidize the container. The basic chemistry of your powder has changed, it is no good for anything but trash.
 
I had a small quantity of IMR 4831 in a steel can go "rusty" just a bit.
I loaded up 5 30-06 180 grain loads with it, and 5 loads to compare, using
a fresh plastic can of IMR 4831. Chronographed the 10 rounds.

The difference? a measly 30 fps average between lots. I've seen more lot-
to-lot differences in fresh powders.

I dumped the rest and burned it, but if it still smells Ok, it is probably safe to use.

I would be concerned if I loaded ammo with it that would not be shot in a short
time. Dave.
 
Tin canister? How long since they've made those? I'm relatively new to this but its all plastic these days...?

That means you missed paper canisters, with metal, rolled onto the top and bottom, with metal pop off tops? Those went the way of the willow appx 30 years ago.

Tins were still available up to 20 years ago and all through the combination carton days.

8 pound kegs were either paper board or painted steel.

25+ pound containers were usually heavy pressed paper. Some had large plastic bags inside of them, some didn't.

As long as it passes the smell test and isn't clumping, I would load it up and use it.

I have some IMR4064 in metal tins that have a bit of rust on the top. Doesn't seem to effect the performance at all. The metal inside the tin is still shiny.

I also had a bunch of surplus #44 powder, IMR3031 equivalent that started clumping as well as turning the metal tops of the cardboard canisters rusty. That stuff was actually corrosive to the bore when shot. Ruined a lovely barrel on a Mod 70 FWT, 257 Rob with it. It was an expensive lesson.

If you only have one tin, dump it. If you have a lot of it, open it all, and check it out. Blend it all together and test a few rounds against newer powder of the same description.

That being said, I've had new off the shelf powders in plastic containers with rust colored dust in them.
 
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LOL, and prior to that they were made of cardboard, with metal tops and bottoms.
Am I dating myself?? :) Dave.

Just last month I finished off the last of a 8 pound cardboard can of Hercules Reloder 7. It was still as good as the day it was produced 30-some years ago.

When I bought the jug I got a copy of the Hercules reloading data from the same era. It is interesting that Reloder 7 was the ONLY rifle powder produced by Hercules at the time.



I was aware of this. I was just wondering how old such a product would be, in case I come across some in the future. Seems the consensus is around 20 years ago they stopped using the tin cans?

I was still buying IMR in tin cans from dealers as recently as 12-13 years ago but chances they were old stock hid in the back of the store. If the seals are kept intact and they are stored properly they should last for at least 30-40 years.
 
A buddy of mine had some IMR 4350 that was quite rusty from the tin container
He gave it to me and I used it to reload 8mm Mauser for my mg 34
It shot just fine with no issues
 
I acquired a # of old powder cans when the old man passed, some had considerable rust dust in them, I used an ordinary kitchen colander and on a breezy day, winnowed the dust out of that powder, used it for years afterwards with no noticeable degradation in accuracy.
 
I found an old tin can of IMR 4895. Rusty and dusty but smelled okay. I went ahead and loaded it all up... red dust everywhere. When I ran some over a chronograph it gave me the lowest ES and SD I'd ever seen in that rifle. Great groups.

Now I was prepared to shoot one round and then spend the weekend pulling bullets. So it is like 30 year old wine sometimes you get vinegar sometimes award winning Bordeaux
 
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