Thanks for all of your responses.
You guys really know your stuff.
Long story short ...
After further inspection, I determined that the bolt was a wee bit too tall.
Not by much at all, but just enough to leave hints of a drag line.
So I removed the bolt, filed it down a bit. Sanded and polished it real good and reinstalled it.
I believe the problem has been solved.
Thanks again for all of your responses.
I've learned a helluva lot from you guys.