Having too narrow rearsight will be more disadvantageous than having one that is too wide. So, start with a rearsight that is a least twice the width of the foresight; i.e. half foresight width of white on each side; and see how you get on. Depending upon how steady your hold is you may wish to widen it slighly or make it a little narrower. But, whenever you make a change make sure that you allow enough time to properly evaluate its effect, good or bad, before making any further adjustment.

What I have said above only applies to one set of conditions. If you shoot on different ranges with varying lighting you may well find that you need to alter your sighting setup slightly.

Rutty