Can you shoot black powder?

I'm going to say no.

I was told by the staff there and I quote “Anything up to 3200 FPS”

I would say no if you can't form a sentence, or spell "with"

I don't think so.

I'm not 100% sure, but I doubt it. I've never seen an indoor range that does. It's probably addressed on the range rules portion of their website.