Welcome aboard Duffer, glad you joined. A line on the cylinder is normal. It is caused by the cylinder lock engaging and dis-engaging as the cylinder spins around. I put a dab of grease on my cylinder lock, then wipe off excess from the cylinder after a full rotation.
This pic shows two Judges - the one on the top brand new, the one on the bottom has about three cylinder rotations on it, and you can see the line starting to form.