Accurate shooting and low barleycorn sights don't agree with each other.
Square top sharp front sight, .06 to .08 wide, and a square sharp rear sight are best for me. I make the notch wide enough so the front sight appears crisp thru the opening. Sight opening varies with age.
Last shoot I went to, I had to choose one of my front sights to use, the left or the right one. I picked the darkest one. By the end of the day, I forgot about the second sight, my mind must have erased it, or my vision got better with some coffee in me. Oh, well, I had fun.
Tom