>I've got a 12 gun fire retardant safe and I keep my powder on the upper shelf
This is what firefighters might call " a bomb". A tight, strong container is not where powder should be stored. Mine is in a wooden chest. It has a lock, from bygone days when kiddies were in the house, but even locked it is lightly contructed and provides no resistance should things ever get too hot.
There is a sample of Laflin & Rand (aka: Hercules) now Alliant Unique that was placed in storage under water in 1899. It was tested in 1996. They say it will be tested again this century and is expected to perform as well as when it was made. (From The ABC's of Reloading 8th edition).Hi. Just to expand on this question, how long can powder be stored for if it is in its original sealed container and kept in a cool dry place? How about if you opened the container, used half, with the remainder still in the original but now unsealed container? What are the indicators that the powder has gone bad? Thanks.
Some good words of wisdom right there!Confining powder or primers in a none vented metal container is not wise.