Groo here
Hate me if you like but,,
get a set of Pachmyre grips [ used at gun show cheep]
This will stop any slip and help with the kick. [ the thin ones]
Shoot the gun with mill spec 45 [ 230gr at 830fps]
When you grip the gun, tighter till it shakes, looser till it don't.
Shoot single action , from a rest if possible, at a round target
Post under dot and see where it hits.
I like the bullet to hit the top of the front sight at 50 yds [ at least]
At 7yds the group will be about the same.
Lighter boolets hit lower, heaver hit higher.
For some reason , speed , does not effect the vertical as much as weight.
For an all around , I might try a 200gr boolet at 900fps.
185's will hit lower, 230's a might higher.