I had a few cans of Nobel Pistol Powder #3, and it was like Bullseye.
I don't know about #2.
If you have a chronograph it's easy to find out. Load one round of your #2 as if its Bullseye (generally the fastest burning powder).
If the velocity is lower than the expected book value, load one with the book weight of Unique. Is it in the range of expected velocity now? Done! If not experiment a little more.