Ought to be. I had to find the 20% stabilizer rule, and why, but the military tests gun powders and flushes propellant lots and ammunition lots out of inventory when there is 20% or less stabilizer. Of course, they are not testing every day, so some lots have a lot less stabilizer than others, when pulled.
The 20% rule is based on the assumption the gunpowder with 20% stabilizer will not ignite in five years. Which is an assumption, but a working assumption. Gunpowder is not a particular auto ignition risk inside cartridges as the case is a heat sink and will draw heat away from the gunpowder. (A Naval Insensitive Munitions expert who had written after action Kaboom reports claimed in his experience, this theory is bogus). But everyone agrees, in bulk, old gunpowder will auto ignite at some point of deterioration. Camp Minden Louisiana demills all sorts of cannon and small arms powders. The guys at Clark's Guns, just down the road, hear kabooms all the time. One of the bigger kabooms, heard like 90 miles away, was due to smokeless propellants autocombusting in bulk. Like pallet loads of the stuff. In bulk is like the amount of stuff in a can, or keg.
Old pull down powder, shoot it up before you start getting case neck cracks, and it starts smelling bitter. It is only a matter of time. And you don't know when clock started. Sellers are quite willing to give you magic beans for your cow.
