mick 41,
The proper method of storing of Black Powder is certainly a good question. After one purchases black powder from any source it then becomes a personal responsibility to store said powder properly.
Basic powder storage cautions are to utilize an area that allows for the least amount of temperature and humidity flucuations.
The United States Department of Transportation (DOT) print rules for quantities, transportation and storage of smokeless and black powder. Reading the DOT rules can be quite intimadating to say the very least.
Even more so are the individual states and their requirements for quantities, transportation and storage of powders. California comes to mind!!!! The State of California has rules about powder that their own Attorney General cannot interpet. Neadless to say when one reads the California powder ownership and storage rules it plainly state that the limit for personal use IS one pound of powder. Some may argue with this statement. All that needs to be done is research the California printed rules pertaining to gunpowder ownership. It is a quagmire.
As to other states, it is up to the individual to research and study the applicable rules for gunpowder storage. Rules for smokeless powders are NOT near as stringent as those rules for black powder. Individual states can and do have more stringent rules then exsiting DOT rules when it comes to gun powder. Large cities may even forbid ownership and/or storage.
This may seem like it is long winded and negative. Some may want to poo-poo away the requirements and stand "well those stupid rules have never been enforced". Not so, just the real world.
My personal opinion, (which is directly opposite of most encountered printed black powder storage rules) is to keep it in a cool, dry and inaccessible location to others. Liability being what it is in todays litigous world, limited access to any gun powder whether smokeless or black powder is to be taken very seriously.
From the Land of Enchantment,
ShortStake,
Deming, New Mexico