shermanrm, tried felt pad under tc's maxi ball it was about a 6" group at 50yds with t7 pellets. was wanting to use the maxi's on elk. the t7 granuals and power belts, hornady conicals and t7 primers shot a little better at 50yds.
BH209 calls for regular cleaning solvents not to use water as with t7. I agree about the removing of bore butter with sabots.
I have fired close to 100 conicals with poor accuracy using t7 powder. the only thing I have found is sabots shoot in my tc where I feel confident with the groups. can't say for sure if it's the powder, but my tc likes sabots. spike