Mike - I want some of those 16bore paradox bulets.
Do you have the mould?

Doug - how much does your gun weigh?
It's not impossible that it's set up for that load, show us all the proofs.
Weigh the gun and weigh the barrels.
If I recall, the *12bore* fosbery paradox projectile goes at 740 grains.

Also - the fellows who are doing nfb for bore rifles often end up working with blue dot.
There's a standard formula, but I don't have it and I haven't been doing nfb in my bore rifle loads. I shoot real charcoal. Might try nfb some day, but I don't crave the complication at this time.

Gatsby or JAZ will chime in soon I'm sure.
They know the nitro business.