I ran a search on this to no avail. I'm thinking of stocking up but don't want any of it to go bad on me. It will be stored at a fairly constant 74 degrees in an air-conditioned home(at least until I move). Any idea how long powder will store in that sort of environment in its original sealed container? Any variables I need to be aware of? Does the brand or type make a difference?

Any advice from the experienced and/or informed folks here is much appreciated.

Well, if it is any help, Bruce Hodgdon sold his surplus WWII 4831 well into the seventies. Lots of it sold in paper bags. So, if you keep it somewhat cool, dry, and dark, 30 years would be a reasonable minimum number. JMO, Dutch.

An Army document on the storage of smokeless propellant available online states that the estimated life is 50-75 years.

I'm shooting a bunch of 1941-42 .45 ACP right now, and it's like new. The Army's estimate was conservative.

Thanks, fellas. Maybe someone would like to comment re: the effect of sunlight hitting the containers part of the day through doors/windows. Is that a no-no, or not an issue at all? How about humidity(if the A/C malfunctions for a time)? My powder comes in heavy black plastic containers, if that means anything.

Lloyd,

I do store them in a closet, but it has no doors, and a little bit of sun in the morning hours hits the container closest to the front edge of the shelf(The shelf is pretty deep, so the ones toward the back stay in the dark.). I might be able to rearrange things to eliminate exposure to the sun -I'll see. Doors would restrict access to certain parts of the closet, so I don't have plans to install them.

Thanks for your input.

You don't want to let 'em get significantly warmer than the ambient room temperature. Heat is the main thing that accelerates powder aging.

I keep mine in a cooler in the garage with the lid closed but not latched. I have a thermometer inside just to see what the temp. reads, and it stays right around 70F degrees year round here in Texas.

I'm using some surplus 4831 that was over 20 years old when I started using it in 1965 and it performs just the same at then today. While I would feel better about storing it in a climate-controlled space, it never has been and doesn't seem to have suffered for it.