senecahornet said:
Yes the powder is like new. I stored it in a dry basement over the years.
That's how I stored my 3100: a sealed container in dry basement.
Time is all it takes to leads to eventually breakdown. For that reason, the military puts limits on how long they will stockpile a powder or munitions loaded with it. 20 years for double-base powders and 45-years for single-base powders in the proper temperature range in storage bunkers. Mind you, those are bulk powders, so the lot age is uniform. But bulk powders have wider burn rate variation than is acceptable for fixed-weight load data. It can have variation because bulk powder users have pressure guns to adjust loads with. But the average handloader relies on databooks and can't confirm pressure. To overcome that, cannister grade powders sold for handloading are typically blended with other, older lots that had previously been identified as slower or faster bulk lots of the same type of powder. The blending is done with whichever of the older powders is needed to adjust the burn rate of the latest lot to qualify it as close enough to the nominal burn rate to be used with databook recipes. That's very convenient for handloaders, but it means you have no idea how old the oldest grains of powder in your container are, and if they start breaking down, the acid products they evolve will destroy the newer powder. This is why you see occasional
recalls of powder that seem to be breaking down prematurely.
Norma guarantees powder you buy will last 10 years. Most will last much longer. If you are lucky and your powder lot is pure because the bulk lot it came from just happened to have the right burn rate without blending, then it can last many decades. Keeping powder in sealed containers in a freezer will also greatly extend its life.
