Supposedly it was stored in a location where it became damp, then tarnished, and was tumbled long enough to not only clean it up nice and pretty, but also break the powder down into smaller kernels, thus changing the burn rate. The tips were repainted, and it was shipped to the US where it proceeded to blow up a few guns.
Lucky me, I just got 20 or 30 rounds of it in a large lot of ammo.