Locating top of round barrel for sight mounting

[Larry (Omaha)]

Hello all,
I have a round rifle barrel that I will ultimately be mounting front and rear sights on. What is the best way to determine the top of the barrel for fitting dovetails? Thanks.

I may be sticking my neck out with respect to protocol, but a sight is nothing more than a reference point. Ever pick a gun up and you don't like the sights?
Right, they are not always to your preferences. I just eyeball front to back using the tang or rear sight as reference and then double sticky back tape the front sight on. Shoulder the gun, aim, and tweak until I like it. I then would solder or dove tail. Works for me.
Larry