I've never used the Thor myself and admittedly don't have a lot of experience with bore sized bullets. I do know from other's experience, they are an outstanding bore size bullet. The right size is the key and as I understand it, Thor is very good at helping.
There are a number of shooter/hunters in the western states that use Thor bullets. Most all are shooting them from PRODUCTION rifles, with production charges and many are using BH. As I understand it, Thor will send a sample package, giving you the opportunity to determine the best size for your specific bore.
How well the Thor may shoot from your rifle, using heavier than production rifle charges, is something you'll have to experiment with. It may require the use of a wad, such as some smokeless shooters use.
IMO..... in-line muzzleloader hunters in the western states, should band together like the traditional shooters and demand sabots be allowed. Not intending to P off the traditionalist shooters but, no reason not to allow saboted bullet like the majority of the country.