Home Forums Hunting & Shooting Ask The Gunwriters Powder storage

I have some fairly old powder that came in metal top cans and paper walls on those cans and it seems to be ok, probably bought new in the 1960’s. I keep the powder stored between 60 and 75 degrees Fahrenheit and try to keep humidity controlled 30 to 40 percent.
I’ve also bought powder at gun shows that I ended up using as lawn fertilizer.
I read about the powder “Unique” being stored wet since it first came out. The test was made - drying out the powder and comparing to new manufacture. This test was done a few years ago.
My memory isn’t good, but it seems the original manufacture date was somewhere around 1890. Is that possible?

I don’t want to store the powder I have in water. But I am wondering if the powder manufacturer’s recommend a “best environment” for powder storage.

Thanks

Bugger

No secrets and no magic. Try SAAMI for detail. I've seen reports that the same powder will fail in days at higher temperatures and go hundreds of years under best conditions. Dave Emary writing in Guns & Ammo has a table with a specific but not named double base powder that at 70 degrees f. has a cook off time of 1708 years and at 200 degrees f. will cook off in the course of the 8th day at that temperature. Cook off is a mild way to describe a potential disaster.
Guns & Ammo
March 10, 2021
By Dave Emary

No powder lasts forever as residual acid and "stabilizer" continue to interact until the powder goes bad. Notice that going bad doesn't mean loses performance it means becomes dangerous to be around. It has been suggested that the cooler, including a freezer as with flashlight batteries and old style photo film, the better to suppress chemical reactions between residual acid and stabilizer. The water storage report is essentially accurate see Phil Sharpe and other writers who try to be complete beyond a brief magazine article. This from a manufacturer is based on SAAMI:


I know I have become too casual about aging powder as I shoot less and store more just as I was probably too casual in thinking of my dedicated precision guns as remote hole punches and sporting firearms as distinguished from weapons. I still don't call a S&W Model 41 a weapon but I should worry more about the tension between leaving powder sealed and checking on it.

No, Bullseye came about 1898, Unique was 1900. Their predecessor Infallible was 1890.

Bugger,

I published an article on this years ago, after doing considerable research.

There are various ways to store powder safely, primarily involving making sure it doesn't get too warm--as Clark pointed out. But powder canisters also shouldn't be kept inside tightly closed storage containers that could "explode" during a fire.

My primary reloading area is one end our unheated and non-air-conditioned garage, which can get pretty hot during summer, even in Montana. Right now I have around 90 different kinds of smokeless powder, and want to keep it reasonably accessible for article assignments, instead of having to paw through a refrigerator. Even a pretty big fridge wouldn't hold it all anyway, though the total amount of powder is still within recommended limits. (In general, local fire-department regulations recommend keeping no more than 200 pounds on hand, one of the items discovered during my research for the article.)

My solution was putting the powder canisters in insulated plastic coolers, which can be purchased relatively cheaply. I have separate coolers for various brands of powder, and thanks to our local area cooling down at night even during late summer, the insides of the coolers never exceed 70 degrees during hot, sunny afternoons. (Have checked this a number of times since starting to use the coolers.) We moved into this house in 1998, and even the oldest powders on hand still perform the same as when new.

I suspect whatever storage method you're using works fine, given the temperatures you mentioned.

I don't have near the inventory that MD has but at last count there were 25 different powders some bought in the 60's. I keep them in an old refrigerator and haven't had any go bad yet.
"Store in a cool dry place" comes to mind.

Patrick Sweeney July 19, 2007: I have no idea what might have happened in the transition to Hercules with trust busting at Du Pont and then Alliant and so it goes. I know single and double based powders are compounded differently and age differently. I gather modern cannister smokeless powders are pretty stable, non hygroscopic and have many fine keeping qualities. I also knew a thoroughly nice guy who died in a powder flare described as a bit of the sun come down to earth. I gather but do not know that wet stowage as in tank ammunition is or at least has been industry practice for some purposes. I don't know any primary sources for information on the old, wet stored powder tale. Googling there was a thread on Brian Enos that referenced the Hercules employee who conducted one such test.

I also know that with war time conditions and the many places making powder over time that there have been some interesting events. There are many reports of large quantities of Hodgdon surplus powders lasting decades in homes and barns until finally used up; both the 4895 the Hodgdon's started with and the 4831 and other powders added. It's been suggested that some of the differences in recommended loads, especially surplus 4831, were related to age and storage. Bryan Litz and few others have good even important information on humidity and variations in moisture content. Apparently variations in moisture content matters more for precision than I for one ever knew - then again for my purposes maybe not so much. Storage temperatures can change use a little bit. I vaguely recall one tale from WWII in the Pacific where anti aircraft artillery fired shells to somewhat higher elevations with fuses adjusted accordingly because the magazine temperatures and so the ammunition temperatures were above normal.

Hodgdon for one and I think others used to bind the national fire code into some of their loading manuals. I strongly encourage folks to at least check their local rules and regulations - whether followed precisely or not. For instance in one town in Western Washington the law is no more than 50 pounds on site in original containers not to exceed one pound each - doesn't affect many people but it cramps a big box store there. I suspect but do not know that this was a reaction to some local fire. I hadn't thought about Don's powder flare death in years. Just maybe I'll dispose of some of the older odds and ends like a partial can of H205 I used to magnumize a .30-'06 and think about putting my war reserve quantities in original containers in styrofoam coolers but under water - thoughts?.

The image below is a scan from an Alliant reloading booklet published in the mid-1990s at the time when Hercules became Alliant. I think it was a reprint of an ad created to assure reloaders that Hercules products were not going to change even if the name of the manufacturer was altered. I don't know that the ad qualifies as a primary source.

About thirteen years ago I posted the image on a thread in the reloading forum of shotgunworld.com, and an Alliant tech posted a confirmation of the type of powder. However the underwater was a sample of an early production batch and was missing some stabilizing chemicals that were soon to be added to smokeless powders, as described in the ad. Underwater storage prevented its decomposition, but I suspect this is due to something more complex than exclusion of atmospheric oxygen. The jar was kept around the offices as a sort of tourist attraction, and was tested occasionally by the lab technicians out of curiosity to find whether it would still go Bang,

--Bob
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