What's the usable life expectancy of open cans of power?

[Point&Shoot]

I have a variety of open one pound cans of a bunch of different powders. Do they deteriorate significantly after being opened and is there an empirical way for the a way for the average Joe to measure the deterioration. I figure a lot of guys buy 5 lb cans. That loads an awful lot of handgun rounds requiring a lot of time at the press. I can get the larger cans but even with the savings I'm still buying the one pounders simply because they are individually sealed. I guess burn rate is way out of my capabilities.
Thanks folks

 

[Hetzer]

They sell power in cans now!!!!

Gotta grab me a six pack for lunch,

 

[DW357]

I had always wondered about this too. From what I gather, as long as they’re stored in a cool dry place they should “last” awhile? How long is “awhile” I dunno...

 

[greencobra]

dunno, but i've used unique from an old can that had to be 40 years plus easy and it worked fine. if any deterioration was going on, i didn't notice. didn't chronograph it. when the component shortage hit 5 years ago, i used 2230 for 223/5.56 and it was scarce as the proverbial hens tooth so i bought every bit i could buy at the time. i'm sitting on ~28 lbs of it now and fully intend to be using it for the rest of my life with no worries.

 

[Woodstock]

If it has a sharp, acid smell it's deteriorating, usually from poor storage. I've got powders from decades ago that still work fine. I've heard they lose a little steam as they get real old.

 

[Point&Shoot]

Maybe a 1/3 of of the open one pound bottles, cans, jars, canisters, and jugs are in seal a meal bags. IDK what happened. I was happy enough with a couple of powders for all my (pistol( shooting than along came the shortage. Being unable to find our powder of choice we pretty much bought EVERYTHING we could find and made it work. For me that resulted in a whole bunch of single pound containers. Aside from procuring powder I have enough clean range lead ingots to sink a Boston Whaler.

Well it may be a mute point anyway. It occurred to me that I've shot some very old cartridges without issues that I can remember so powders in the right environment will probably outlast me.

 

[Ranger007]

I have several opened and stored in cool dry place going on years and years no problems what so ever.

 

[NavelOfficer]

Dido everything above. Unless you are doing precision loads, most ancient powders that still look like powder will work. That said, I had some Bullseye from the metal can era (like the Unique above) that didn't function in my 9mm pistol using starting loads. Perhaps new powder would have been similar...don't know. I suspect you lose some oomph with older powders, but do a few test loads in plinkers and if it works, use it up and have some economical trigger time.
I'm assuming the fine rust-colored powder that sometimes accompanies old powder is a sign of deterioration, but transfer the powder with a slight breeze to blow it away and continue reloading. Not ideal, but it still gives you plenty of plinking pleasure.
Again, don't rely on these powders for critical use. At worst, throw it on the grass or pour it out on a flat rock and burn it off.

 

[EddieZoom]

I've personally used ~20 year old powder without a single issue. Chrono shows that it's about where it should be.

Seems it's pretty tough to kill powder...and primers.

 

[mac1911]

I remeber reading a article Alliant was testing a batch of red dot every year that was very old.
IIRC they stopped testing as it proved out that properly stored powder last a long time.

I have some hurco thats in the old carbaord tube "cans" its at least 20 years old. Still use it for shotgun loads.
I have some Clays powder from 2004 tbat shows no signs of being bad and recently loaded some 45 acp and 38s with it?
If it looks funny or clumps up and smells odd chances are its not good. If you have poor perfomance its most likely bad also.

 

[xtry51]

I don't have anything obscenely old, but normal sitting on a basement shelf in plastic bottles storage has shown no change in about 6 years for a couple I use rarely for precision .308 loading. They chrono same this year as they did when I first worked the load up.

 

[EddieCoyle]

20 years for double base, 40 years for single base. Shorter if you let it get hot.

Depending on the exact chemistry, double base powder can get dangerous when it ages. That's why the .gov surpluses ammo, and why old ammo dumps sometimes explode.

When I read about people shooting WWII-era (and older) ammo, I cringe. It works OK until it doesn't, and then the gun blows up in your face.

 

[Wickedcoolname]

I'm still loading powder I bought from Perry White's gun shop. I think he closed 30 years ago.

 

[DW357]

20 years for double base, 40 years for single base. Shorter if you let it get hot.

Depending on the exact chemistry, double base powder can get dangerous when it ages. That's why the .gov surpluses ammo, and why old ammo dumps sometimes explode.

Interesting. Good to know.

 

[EddieCoyle]

I'm still loading powder I bought from Perry White's gun shop. I think he closed 30 years ago.

Clark Kent's boss had a gun shop?

 

[DarthRevan]

They sell power in cans now!!!!

Gotta grab me a six pack for lunch,

 

[Eric H]

I'm still loading powder I bought from Perry White's gun shop. I think he closed 30 years ago.

I'm still loading with powder and using some equipment someone else originally bought from Perry White's.