old powder question

toad67

I have 2 old IMR 4350 metal cans of powder. I noticed that when I opened them up there was rust in the powder. I had an old empty plastic can of H4350, pulled the label off of it, relabeled it for the IMR and dumped it in there. Does the rust in the powder hurt anything? After dumping them it appears that there might be more rust than what I might think is acceptable. The powder does smell fine. Thanks.

Todd

Ambrose

That powder has deteriorated. I wouldn't use it and I advise you not to use it, either. Best case is that it will not give you the same velocity and accuracy as new powder and worst case--I will leave to your imagination. Spread it on the lawn or the flower beds for fertilizer or pour a trail of it outside and light it.

XXCross

Well Toad,
I think you should use it.....on your lawn, in your garden, or just to light the barbi. Just don't put it in a gun.

Rocky Raab

Yes. That is NOT rust. It is what's left of deteriorated powder. Get rid of that stuff IMMEDIATELY. Exposing it to air by pouring can speed the decomposition and it can even self-combust.

oneoldsap

If you compare the cost of one Emergency Room visit to the cost of a pound of powder , it becomes a no-brainer !

jonk

You know, I have yet to see any powder do this but I hear about it often enough so am sure it happens. I've seen degraded powder but it had other characteristics entirely. I'd love to do some tests someday with a chronograph and pressure gauge of supposedly degraded powder, in a beater gun behind a blast shield, to see if the commonly stated truth holds true.

Failing that I would say follow the good advice here and toss it, burn it, etc.

Rocky Raab

Jonk, I ran a few tests with some "rusty" IMR4227 in a Hornet once. I didn't have a pressure system back then, but velocities and groups were all over the place. It was extremely erratic. Enough to cause me to stop those tests forthwith - and to erase any doubt I may have had about the usual advice on bad powder.

Furthermore, I recall reading a piece by John Wooters in which he picked a can of powder out of his FULL powder locker, only to realize that the can was HOT. It was perhaps only minutes from self-combusting, and he RAN not walked to toss it safely outdoors.

toad67

What causes this type of reaction? If a can of powder is stored in a locker as Rocky mentioned then what causes it to deteriorate with out any outside involvment? It seems like it would need some air to make such a drastic change. FYI I put all of my old powder omn my flowerbeds, thanks for the info.

Todd

Rocky Raab

Air (oxygen) will speed up the reaction, but it is actually caused by residual acids in the powder. In production, the powder is rinsed enough to remove 99.999% or so of the strong acids used to create the nitrocellulose - but they can't get it all. So eventually, you get some oxidation. The problem is worst in single-base powders, hardly a problem at all in double-base and nonexistent in spherical double-base powders because of the extra washing and rinsing steps involved in making the latter two.

Single-base powders will eventually deteriorate in unopened cans, but it is air exposure that really gets things going. Pouring it into and out of a measure obviously introduces more air than merely opening a can, so once you start using a single-base powder, it is best to use it up in a reasonable amount of time. How long that might be depends on a lot of things, but you ought to have several years. Some WWII powder is still around and still good - IF it has been stored properly.

toad67

So if it will do it in the unopened powder cans what is it doing in reloads that are of the same vintage?

Rocky Raab

Ahhhh, that's the sixty-four dollar question, isn't it? The fact is, unless you break down a few rounds of really old ammo, you can't know if the powder inside has gone south. How many times have you heard of old ammo being really erratic? Lots, probably. So there's a possibility that bad powder is the reason.

toad67

So then for the sixty five dollar question what is a good estimate for powder life, whether being in a loaded round or in the container. How much difference does air really make in the breakdown of the powder if a person was to open the container and load 50 or so rounds every few years?

Rocky Raab

It depends a lot on how it's stored. Cool and dry storage means it'll last for decades. Keep it in your attic and it could go bad in a few years.

I think that I've created an excessive fear about this. In almost all instances, it isn't a problem. Store powder (and ammo) correctly and you should never see a problem with deterioration in your lifetime. If you do see rusty dust in powder, it is not safe to use and should be disposed of by scattering thinly on the lawn or garden.

The vast majority of reloaders will never have a bad can. Those few who do will likely never see another one.