I'm about to stock up on powder. Years' worth of powder. I'm debating between buying in 8 lb jugs vs 1 lb cans.
Is it better to store an opened/unsealed for years, or is it better to forgo the savings of buying in bulk so that I can open/unseal 1 lb at a time, thereby keeping the majority of my powder factory sealed until I need it?
I buy powders I use more often in 8 lb containers. For powders you use continuously, I would suggest 8 lb containers as many posted, you can transfer into 1 lb containers. So buy 1 lb container along with 8 lb container and once 1 lb container is used up, pour from 8 lb container.
Your concern of "unsealing" factory sealed container may be overshadowed by gradual decomposition of powder which will continue even inside sealed containers.
I prefer to use up powders within several years while in "optimal" condition to avoid decomposition of powder (Read below). If you are planning to store powder for years, I would suggest cool place out of sunlight as cooler storage temperature slows decomposition of powder. Will properly stored powder be "safe" to use for years and decades? Many report yes but question is will it be "optimal" to use?
On the other hand, primers are made to withstand moisture and long-term storage with physical barrier/sealant applied to priming compound. For the same amount of funds, I would focus more on stocking up on primers than powder, especially when primers go on sale (this past year for $20-$25/1000 for S&B and Winchester with free shipping).
Everglades still has CCI/Winchester SP/SR primers for $26/1000 -
https://www.thehighroad.org/index.p...ponents-on-sale.707473/page-175#post-11117453
Different brand primers showing different color barriers for protecting priming compound -
https://www.thehighroad.org/index.p...ts-your-experience.630512/page-2#post-7794378
FYI, this from Hodgdon on storage of powder -
https://www.hodgdonreloading.com/reloading-education/safety/gunpowder-stability
"
Smokeless Propellant
The main ingredient of smokeless propellant, comprising from about 55% to 90% of the composition, is nitrocellulose. The process of creating nitrocellulose leaves remnant acid in the material. This acid immediately starts decomposing the finished product. Left alone the decomposition will reach the stage where the propellant becomes unstable and self-ignites. This process resulted in massive explosions at U.S. Government arsenals after World War I.
To increase the life of the smokeless propellant, a stabilizing chemical is used. This “stabilizer” reacts with the acid to slow down the decomposition process. However, as the stabilizer reacts with the acid it is consumed. After the stabilizer is totally consumed, the propellant is no longer protected from the internal acid.
The entire stabilizer / decomposition process is a time and temperature function – the higher the temperature, the shorter the safe life of the powder. Even moderate temperature, over extended time, leads to propellant decomposition. As a rule of thumb, any temperature over that which is comfortable to a person is accelerating the decomposition of smokeless propellants.
Under proper storage, modern smokeless powder can last for decades. However, this does not mean the reloader can ignore how the powder is stored, particularly if in an uncontrolled environment such as a garage or storage building."
And short-term storage of powder in hoppers -
https://www.hodgdon.com/wp-content/uploads/2017/10/website-warnings-general.pdf
"Powder left in the reloader’s powder measure hoppers for extended periods, overnight or several days, should be avoided. Powder needs to be stored in original containers ONLY when not in use.
Numerous modern smokeless powders are double base in construction, containing both Nitrocellulose and Nitroglycerine. Many powder measures use plastics containing polystyrene, which Nitroglycerine adversely affects when contact is made for extended periods of time, resulting in etching or misshaping the plastic.
Normal usage during the reloading process does not provide adequate time for this to occur, so simply draining hoppers into the original containers when the reloading is completed for the day, prevents damaging the hoppers."