Yeah, @Zonie, I am an engineer too. While I haven't actually verified the conductivity on my black powder cans, I was certain they were of the conductive variety. I don't have any Pyrodex to check either.By golly, your right.
I got curious so, using my multi-meter I checked to see if the plastic bottle some Schuetzen powder is in was conductive. With the meter set to the 20M ohm's scale, I got readings of conductivity between the two probes on numerous tests.
Doing the same test on the black plastic bottle some Pyrodex is in, I got 0.0000 ohms indicating that the Pyrodex bottles are made from non-conductive plastic.