[Boatanchors] Filament Choke

[Wilson Lamb]

My magnetics training is lacking (absent) and I'm short on time right now, so help is requested.
I have an Amidon R61-050-750 ferrite rod, 0.5" dia and 7.5" length.
It is a 61 mix, permeability 125, Al 49.
Can anyone provide an equation for its inductance fully wound with bifilar 10 AWG wire?
Amidon says it's best above 40m, but I'm not sure that's as a fil choke.
Thanks,
Wilson