congrats on the new TC. I have a Triumph too and you will find it to be an excellent shooter. Try starting with 90-100grs of Black Horn and TC 250 gr super shockwave bullets and sabots, you may not have to alter anything else. I also use CCI 209 primers. Again you made a good choise.!
I'm not much on pellets and prefer loose powder. See my above post on what I send through my TC Triumph. How did you get the pellets to fire in a flintlock? I've heard something on pellet firing flintlocks but don't know anything about them. Just interested as a fellow flintlock shooter.