For legal reasons I could not possibly comment on its effect on roundball. I live on a land governed with funny laws!Excellent. Much appreciated and I will give it a shot. You know, the muzzle does look a little thicker on one side, but I figured it was my eye sight/glasses throwing it off. Maybe this will finally give me the fix I needed. Makes sense too, because if looking down the bore it's appears thicker at the muzzle where current POI is, so if filing a muzzle is like adjusting a front sight, then that means this will work.
EDIT: I do want to make sure, this will work for round ball correct?
Give it a shot. It's no big deal. But do sprinkle the blood of a day old chick on it first .
What you say is correct and I never thought of it before but yes, the direction you would adjust a frontsight to is the same side you need to vent earlier.
Don't remove mor than say .040" at a time without testing.