11 August 2022
If a T/C Contender, you have some more flexibility although bbl twist rate of 1:10 will be the determining factor - so I have been told. There is a practical limit to the range of bullet weights due to case size. I use H110 for the 32-20 loads in my T/C shooting 110gr bullets. The 32 Mag can also use H110 for the heavier bullets but I am assuming here that you are shooting in a T/C Contender. If a revolver, the shorter bbl will make a faster propellant more productive.
I would work the loads up with Unique. Herco, like Blue Dot, is a sensitive propellant and pressures can get extreme very fast. HP38 is great but a real fast powder. TiteGrp may show promise but man, Unique is the best all around general purpose powder ever made.
Here is that varmint load in the 32-20.
With rifle in hand, I confidently go forth into the darkness.