How old is too old for powder?

[roverboy]

I had some IMR4350 go bad a few years ago and it ate a hole through the metal lid. Talk about gas wanting a way out.

[dale2242]

I am using some WW2 vintage H4831 that is still good.
It has been stored in the original 50# cardboard container in a cool dry spot...dale

[1hole]

How old is "too old" for smokeless powder? It varies by the chemistry and average temp, neither of which work in straight lines. Powder is organic chemistry and all organic things degrade by time and heat. Store any powder in a home freezer and most of it's gonna last nearly forever. There is no magic temp., store you powder warmer places and aging things happen faster. Temp stability or fluctuations, as such, hardly matter, it's the combined time/temp exposure curve that kills powder and seems each powder has it's own life limits.

My first powder purchase (in 1965) was a 50# keg of 1941-45 WWII surplus "4831", the stuff that started Bruce Hodgdon out. I still have a couple pounds of it, no smell and no "rust", and, best I can tell, it still works like new.

On the other hand I've had a couple cans of Dupont labeled IMR 4895 and IMR 4320 go rusty/stinky bad in only about 20 years of setting on the same shelf as the much older 4831; you figger it out, I can't.

[sargenv]

A friend gave me a good amount of Dupont Pistol #6 recently. I loaded a bunch of it in 38 Spl with data gleaned from I think Speer #7 and so far so good.. Nice light 38 spl loads.

[McFred]

110 year old 8x57 pulldown powder seems to work just fine:

http://forums.accuratereloading.com/...3/m/9391000342

In other words, don't worry about age, just condition.

[Wolverine19D]

I wish there was a chart with what powders lasted the longest. Many say single based powders outlive double based powders but when it comes to personal experiences it seems like single based stick powders go bad well before double based ball powders stored in the same conditions.

I am newer to reloading so the only experience I have is an old can of 4064 my uncle had in the garage for 30+ years. A little rust on the outside of the can but the powder was perfect and still had the strong ammonia smell of new powder. The garage would be freezing in the winter and over 90 degrees during most summer days.

Edited to add, to the poster above mentioning storing powder in the freezer to keep it long term - do you mean store it with the freezer running inside the house or just inside the freezer but turned off to use it for an insulated box? I would think if the freezer were to be turned on it would build up a lot of moisture on the powder inside. Perhaps this was stupid question and everybody but me knew you meant for the freezer to be un-plugged.