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Every time someone brings up the "Mojo" sights, I wonder if a discussion of optics isn't needed. An aperture rear sight can aid aiming considerably by eliminating out-of-focus effects at front sight and target - but only if the aperture is smaller than the pupil of the eye looking through it.

Because it is located forward of the receiver, the "Mojo" design requires a fairly large aperture to permit a decent view of the target. (Anyone who ever used one of the tiny apertures on a US M1903 knows how difficult it can be to stay on the right target with a small, distant aperture.)

Since the "Mojo" aperture is little or no smaller than the pupil, it can't block the extraneous light rays that make the front sight and target impossible to focus simultaneously. On the other hand, a proper aperture sight located as close as possible to the eye can be much smaller than the pupil and will make both front sight and target appear much sharper.

This is why competitive iron-sight target rifles are equipped with receiver or tang sights positioned close to the eye. It makes optical sense for bullseye target shooting. It that's what you're going to do, save your money for a decent receiver sight and forget the "Mojo".

If you like to use the issue open sights, you can get the same optical benefit by sticking a small aperture to your glasses and sighting through it. Both sights and target will look sharper. (Of course the same trick will help with the "Mojo".)

In the photos below, camera is focused on the front sight.

1. Distant large aperture sight seen through wide pupil (f 3.2) - target indistinct.
2. Notch sight at same setting - still too fuzzy.
3. Notch sight picture through small aperture (f 8.0) - usable.
4. Small rear aperture through wide pupil (f 3.2) - usable.

For plinking and just fooling around, sights of the "Mojo" type are useful and often have more convenient windage and elevation adjustments than the issue open sights. They do not, however, offer any optical benefit or increased accuracy compared to the issue sights for those who have learned to use notch-and-post effectively.

For hunting, I can't imagine wanting to use anything less than the best scope I could afford - for sure target identification and precise shot placement.

In case you're wondering where "diopter" fits in this scheme, that's simply a European term for what we call a "receiver sight" in the USA. These days, many Americans seem to enjoy using the Euro word, but it can be confusing since we traditionally use "diopter (sight)" for one fitted with a single corrective lens.

Not specific enough. In US usage, any aperture sight, even the barrel-mounted horror on our M1903 rifle, is a "Peep".



Worse yet, we call these disgusting confections "Peeps" and consume millions at Easter time!



What a country!