Remodelling apertures?

[Canuck Bob]

I have a question regarding peeps. I have a collection of different inserts from a lifetime of reciver sight buying and stashing. I routinely open them up with a drill press. Lately I have been playing around and find the peep has spider webs to quote Sixgun from another thread.

It is very noticeable in a long shank peep that I drilled out to full ID. I'm now wondering if a peep resembling a little tunnel is not as useable as a sharp edged flat plate? Military apertures tend to be flat plates and now I'm wondering if that for tooling design or optical design.

[J Miller]

The last time I found what looked like spider webs in one of my peep sight apertures, it was some fuzz from the inside of my rifle sock.
A little cleaning took care of it.

I have also seen the difference as you mentioned between a flat plate type of aperture, and the screw in type with the threaded tube. The flat plates seem to give a clearer sight pic.
Although I haven't had any trouble with the screw in types.

Joe

[Model 52B]

Military apertures tend to be flat plates as they are often stamped from sheet steel. It's just a cost of production thing.

The old M16A1 sights were flat on the back and cupped on the front to reduce reflections and glare in some situations. IIRC the M14 uses a similar flat back and a counter bored front face to give a similar effect, and the NM sights use a hooded rear (where the hole is also offset to give a 1/2 MOA vertical adjustment when you rotate it 180 degrees).

Most high end small bore match sights use, or can be made to use, a glare tube that is well over the aperture size, so it becomes a sight looking out of a long tunnel type of arrangement.

Most tang sights screw into the sight elevator so the aperture is looking through the shank, which is also over sized, but not as much as a glare tube. It's important in that case that the sight actually be aligned with the front sight. If it's tilted a bit too far forward or aft, then you are 1) looking through what is effectively an oval, or 2) your field of view through the sight is restricted as your line of sight is then clipping the edge of the shank, or 3) you've got both problems. 1, 2 or 3 is the reason a flat sight may have a sharper aperture than a deeper sight or a aperture that screws in via a hollow shank. It's not the shank, it's the improper alignment that causes the fuzzy image.

A simple way to check is to move the elevator arm of a tang sight slightly forward and aft while you are in shooting position and see if the sight picture clears. If it does, you've found your problem.

Ensuring the sight elevator is perpendicular to the line of sight is the first/best fix, and if that cannot be achieved, then shortening the shank can help by preventing the vignetting that otherwise occurs.

Here is a Merit #4 Hunter aperture in a Marbles Standard tang sight. The proper thread size comes in a long shank model, and you'll note the shank could be shortened by a full 2 threads. If I was having issues with vignetting, then I'd do just that, but in this case the aperture is perfectly aligned with the line of sight so it's a non issue, and in fact helps reduce glare and improve contrast.

[Ray Newman]

Heed what 52b wrote 'bot the Merit.

[Griff]

Heed what 52b wrote 'bot the Merit.

And the part about the face of the disk needing to be perpendicular to the line of sight, both vertically and horizontally, otherwise you'll get that oval he mentions.

The vertical adjustment on my "no name" tang is an indespensible feature, IMO.


Just on the leading edge of the base is a setscrew for adjusting the angle of the stem.

[Chuck 100 yd]

I drill out the opening of ones I use for hunting about half way between tiny (target) and ghost ring (huge) size. Do some experimenting with size to see what works best for you.

[Steelbanger]

I have a cataract which has been slowly developing for a length of time which is probably 4 or 5 years and still doesn't need the "fix". When I first saw these spider webs I thought something was in the aperture at 3 o-clock. I blew through it, poked a fine wire through, but the web was still there. Next I rotated the peep 180º but the web stayed at 3 o-clock. That was the point when I realized that it wasn't the sight.So I suffer with these ghostly, mysterious, disturbing visions. Probably, when the time comes for it to be removed, I won't be able to hold a rifle to shoot offhand which means I will then have to hang 'em up for good.

Last year Shooting Sports U.S.A. published a very interesting article on what we see through the apertures of our sights. I searched and found the link and hope some of you will find it interesting. http://www.nxtbook.com/nxtbooks/nra/ssu ... startid=24

[earlmck]

I searched and found the link and hope some of you will find it interesting.

Wow! Now that's an eye-opener!

Thanks for the link, Steelbanger.