I have cans of powder that are 35+ years old. I am about to load some Bullseye into some.45ACP's and I have some of the above pictured powders as well, all have been stored in their original cans, in a cool dry place, IE my garage.
As long as they haven't been overheated,.IE above about 150F, or allowed to get wet, there isn't anything wrong with it.
Pour some out and examine, if all of the grains are a normal looking and a consistant graphite color, and the powder pours nicely with no gobs or chunks then it hasn't started to break down.
On the otherhand if there is a sweet smell and there looks to be a yellowish seepage from the grains, or if grains are stuck together in globs, it is bad. This is normally caused by being heated above 150F, Get rid of it!
This is the same thing that happens to dynamite when it breaks down, it starts seeping nitro out of the paper casing. Very touchy stuff at that point.
I asked a gun shop about these old cans I had, and they all said get rid of them because they were too old. However he had ammo on the shelf that was 30+ years old! Also surplus ammo is usually 25-30 years old by the time it becomes surplus. Of course he thought I'd just freak out and buy new powder from him, so it is understandable he would tell me my stuff was unsafe.I didn't, because I was told long ago by them that knows, that the stuff lasts almost indefinately as long as it is stored properly. Indefinately is longer than 50 years.
If powder doesn't go bad in a cartridge then why should it go bad in a sealed can!
This is "MY" .02 on this subject. Use your own best judgement.
However after looking at your picture again I would be leary of the two in the paper containers.
I was taken to task a few months ago by one of our more knowedgeable posters for using some IMR rifle powder that was perhaps 20 years old and had that IMR can "rust dust" on it even though a representative from a powder company told me it was safe to use.
One thought on powder aging in a cartridge vs. its can - there is a lot less air space in a cartridge than in a can, especially if the can is partially empty. Could/should that alter that theory?
Those containers in the back row are from the 60's I still have a unopened 1 lb. can of Hercules Reloader #7 and a can of Norma N205 which is a magnum powder and is not quite a pound as 400 grams is only about 14 oz's. I too had a can of Dupont #4831 that I bought about 1970 for $3.15 and when I opened it up a few years ago noticed orange dust rising up while pouring into the measure.
Obviously none of your powders are black powders. I always heard though that the old black powders can become unstable over many years of storage. Any truth to this?? I can remember my dad burning some old powder in a pit and telling me this. Just curious.
I never heard of black powder deteriorating over time, I have a 3/4 filled can of Dupont FFF powder from around the 20's and it looks very good. As a matter of fact the grains of powder are glossy looking unlike the dull looking Goex you see today, the appearance is similar to Swiss powder if you know what that is.
BP if it is kept dry, never goes bad or becomes unstable. Old smokeless, made after the 1920s will last almost indefinately as long as it isn't overheated or alowed to get damp. Prior to the 1920s, some powders were less chemically stable and may not always keep their burn rate.