Who says I didn't? Not wrong, think about it. The whole point of the peep is that it is close to your eye so it disappears while you focus on the front sight. Your eye automatically centers itself in the aperture. Not to mention that it greatly extends your sight radius. On a handgun, it has none of those advantages, period, undeniable fact. Same for barrel mounting on a rifle. You still have to consciously center the front sight in the aperture. So all you're really doing is putting a top on your rear sight. Looking through and centering your front sight in a doughnut instead of a notch. All you're really doing is giving up precision and obscuring the target area.