Diopter sights work alright, but they are at their best on the rifle range, not in the game fields. A ghost ring rear sight combined with a thick rectangular post front sight is what you're after, unless you go to an optic; red dot, scope, reflex, whatever it may be. Increasing the thickness of the rim, and decreasing the size of the aperture has little advantage in practical shooting applications. The Lyman receiver sight is alright, but I own both, and prefer the Williams Fool Proof if I require a gallows style sight.
A word on the wide rectangular front post sight might be in order, as it appears that many shooters don't understand the advantage it has over a bead, and if they choose a post at all seem to gravitate towards a tapered post. Think of the rectangular post front sight as a cross hair. The flat top provides a precise index of elevation, and takes on the role of the horizontal wire of the cross hair. The human eye is very good at finding the precise center of an object, and the center of the rectangular post takes on the role of the vertical wire of the cross hair. The front sight is placed on the target, then when your focus shifts to it, it appears in sharp relief against the blurred target. Press the trigger, and you'll be rewarded with a hit.
If you happen to find a brass front sight, it has magic qualities, appearing black on a white back ground, and white on a block back ground. Another neat feature of the rectangular post front sight is how it can be manipulated when shooting at bullseye targets. If the center of the bull is the same apparent width as the front sight, if the sight appears to be wider than the bull, it means the sight is not centered on the target. This is a better system than a 30 minute hold, because it does not degrade on a day where clouds move across the sun resulting in variable light conditions, and can make judging the space between the top of the sight and the bottom of the round challenging. Mostly though, the ghost ring and rectangular post sights excel in the field.
