Thank you both for your replies. I will caliper it when I get it, buy a new sight and screw, nut and springs and plunger.
In the mean time, if I want to shoot it right away, will my 686+-6's entire rear sight assembly fit?
I purchased a 28-2 in NY and had it sent to a MD FFL where it is sitting until the waiting period completes.
When I went to the FFL today to start the paperwork, I saw the right side of the rear sight blade had been broken off.
I saw the Midway video on replacing rear sights and realize that...