My senses say that the rifled choke of a paradox barrel will give a roundball an advantage.

I have never owned or shot a true paradox gun though, so let's wait for someone who actually done that to come along and answer that question.

In the meantime, keep reading around - perhaps that's been answered somewhere.
Do you have a copy of Greener's 'The Gun And It's Development'?
There may be good answers in there.

Cheers
Tinker