MidLife

Just curious what the shelf life of modern smokeless powders is?
If they are keep indoors, and lid on in conditioned space, what the expected shelf life would be?

shootist

Unlimited if stored at room temp and kept dry, just used some up that was 25+ years old worked great.

hal

Just keep it sealed good and in a fairly dry location, am shooting powder from 1992.

bhefley59

I have some powders I have had for 30+ years and are still good. Bought a can of H110 at Walmart in 1976 (back then the price tag had the date printed on it ). I loaded some .357 mag loads and used about 1/4 can. then decided I liked Winchester 296 better. A few months ago a buddy wanted me to load some 41 mag for him , just some mid range plinking loads . I pulled the H110 down wiped the dust off, opened opened the can , looks good , smells good . Loaded a couple hundred (all the brass he had ) fired off a few . Works great .

Like said above if you keep it cool and dry and a closed container it should be fine but smell it first should not have a bitter or acid smell ..

MZ5

There are reports of guys in the sandbox running 50BMG ammo in-theater with 1940s headstamps. I do not believe the military pulled down the ammo, re-sized and re-used the cases with new powder, so I'd say the powder life is pretty good.

shootist

Not sure about H110 from 1976, but H110 and Win.296 are one in the same just different lables.

Ruger Redhawk

I'm glad to read this. I knew it had a long shelf life but wasn't sure how long. I have allot of old powder that has to be over 30 years old. Thanks for the info.
I was shooting 45 ACP reloads a couple weeks ago in my SR1911 I loaded in 1989.They shot like I had just loaded them.

shootist

Load a few up and give them a try, long as the powder hasn't discolored or not looking right it will work just fine, my kid buys old WWII surplus rounds for one of his old guns and they all fire.

johnjohn

I think it takes a lot to "make it go bad".

Ruger Redhawk

That's what I plan on doing. I haven't reloaded in years. I loaded allot of reloads years ago then didn't have a place to shoot until recently.Thanks

shootist

There you go, no time like the present get after it

GP100man

I called Hodgdon on H-110 ,they still have batches stored that`s 90 yrs & still A-OK !!

I`ve had some go bad ,but completely my fault , I`ve found that consistent temps (enuff to prevent condensation) is very important.

429421Cowboy

Friends i load with are still loading shotgun shells and .38 rounds with 8lb kegs of Red Dot they bought 30 years ago and i have to say look like they were stored none too careful, but still go bang every time!

Salmoneye

I'm using a keg of Red Dot from 1961...

Iowegan

MidLife, If powder is stored properly (cool and dry, not exposed to air or sunlight) it will likely out live you. Heat and humidity are the biggest enemies but if powder is stored in sealed factory containers where it isn't exposed directly to air .... humidity and sunlight are not factors. The worst thing you can do is to leave powder sitting in the plastic hopper of your powder measure or a powder trickler for more than a few hours. Powder will draw moisture from the air plus chemicals in the plastic will contaminate chemicals in the powder. Humidity levels in factory sealed containers are less than 10% so if "loose" powder is exposed to normal house humidity, it doesn't take long to start deteriorating. If you see "stains" in your clear plastic powder hopper that won't wipe out with a cloth, it means you probably left the powder in it too long and there was a chemical reaction that changed the properties of the powder.

Single base powders have a longer shelf life than double base powders (ie Unique) and are less prone to aging from heat. Powder stored at normal room temperatures take a long time to age, however at temperatures of 100 deg F or more, it doesn't take but a few weeks for deterioration to start.

Back in the 70's, Sierra Army Depot released tests done on military 45 ACP ammo loaded at Redfield Arsenal (Pine Bluff, AR) in 1942 (headstamp RA-42) This ammo was loaded with 5.9gr of canister grade Unique powder. After 10 years in controlled climate storage, there was no notable change in velocity or duds/squibs. After 20 years in controlled storage, reliability was unchanged but velocity had dropped by 2%. At the 30 year mark, duds/squibs per thousand increased and velocity dropped by 10%. Prior to these tests, the Depots would destroy or sell Mil-Surp ammo that was stored 10 years after the headstamp's date of manufacturer. I'm not sure but I think storage time was extended to 20 years for most small arms ammo. Unique powder, being double based, is probably a "worst case scenario".

In recent years, all powder manufacturers went from foil lined cardboard or metal cans to specially formulated plastic containers that do not chemically react with powder. Assuming the factory plastic containers remain sealed and stored at room temperature, any smokeless powder should last at least 30 years ... probably much longer for single base powders. Once a powder jar is opened and exposed to air, it will deteriorate much faster and the rate of deterioration would again depend on heat, humidity, and exposure to light. Powder also deteriorates much faster if it is stored in something other than the factory container, such as TupperWare, other plastics, metal, and especially clear glass jars. Deterioration affects the powder's burn rate. When powders deteriorate, they tend to burn slower, which will reduce chamber pressure and velocity. However, some powders do just the opposite where burn rates are faster, thus increasing chamber pressure. This could get dangerous. Just because an old powder goes bang ... it doesn't mean it has maintained the intended burn rate.

If you "inherit" powder that came in a cardboard, metal, or non-original container or if you are unsure how it was stored, it's best to dispose of it ..... it's just not worth the risk to save a few bucks. Because smokeless powders are very rich in nitrogen, they make excellent fertilizer in gardens or yards .... just make sure you spread it thin.