Congratulations on your 12 bore paradox double! I've been looking for a 16 bore fully rifled double for years, that is in good enough shape to hunt with, but haven't found one yet, at least one I could afford! I have a Pedersoli double rifle I've been thinking of re-boreing to 16 bore, and rifleing, if I can find someone to do the work. The barrels are very heavy on this rifle, and There will be pleanty of wall thickness for 16 bore, but not 12 bore.

I don't have any load data for you, sorry, but there will be pleanty here for you.