Grouse45, this is interesting.

Not BH209 but relevant-

several years back I lent a Renegade to a buddy of mine for the season with the admonition to bring it back clean; when returning it to my shop he mentioned it was ready to go which I took to mean it was cleaned, lubed, and ready for storage.

What he actually meant was that he hadn't fired it at all and it was still charged with a prb and 777, as I found out almost one year later while firing a cap to foul the barrel!

So that was 11 full months in a cabinet, in an unheated (at the time)mudroom, exposed to the cold of winter, the heat and humidity of summer, as well as everything in between- went off instantly.

I was both surprised and impressed.