I am with you, Hardcase.
I don't have a Walker but I have read a lot of other forums today and no one has reported being able to load more than 60 grains with a round ball let alone a conical. Most say accuracy declines beyond 50 grains. No one reports MV greater than 1200 FPS and that is with a round ball and 50 grains.
This one has tough time gtting past the BS filter.
BUT I hasten to repeat, I have zero experience with a Walker.
My reading of history convinces me that most bad government results from too much government. Thomas Jefferson