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Triangle front sight inserts

Posted: Thu Mar 29, 2007 3:58 pm
by mahiker
I understand that some 300 meter competitors use triangle rather than circle front sight inserts. Are there any optical benefits for a Palma competitor( 800/900/1000 yards) ?
Does anyone make adjustable triangle front sights?

Thanks,

Al

Posted: Fri Mar 30, 2007 2:30 am
by RyanIntershoot
Gehmann make an adjustable triangle iris sight, as well as a square one

If you google for Gehmann Triangle Iris 549 you'll get it.

Triangular fore sight elements

Posted: Fri Mar 30, 2007 2:37 am
by peepsight
Also check out AHG Anschutz who make plastic triangle elements in both 18mm & 22mm and they are available in different colours. They are a lot cheaper than an adjustable iris.

Peepsight

Posted: Sun Apr 01, 2007 10:09 am
by Padawan
I have never used the triangular inserts but my coach told me that they are not good to use. the idea of the triangle is to give you three places to check that you are aligned, but the eye movement of this checking actually opens your hold. someone ran a test with some Olympic shooters using these and they all did worse. I don't know any more about the experiment though, sorry.

Triangular fore sight elements

Posted: Sun Apr 01, 2007 11:22 am
by peepsight
According to the information i got from my German friends, the triangular foresight elements were introduced for older shooters who were starting to experience astigmatism. This is where the target and round foresight become oval in shape and the picture starts to 'grey' out.

In older shooters with astigmatism, the eye will struggle to scan the round element for 360 degrees and parts either blurr or become oval.
A good prescription shooting lense is esentual for defective eye sight.

The triangular element has only 3 straight lines for the eye to scan and even with astigmatism, the lines of the triangle remain straight and don't blurr. Well that's the theory. For top Olympic shooters with good eye sight, the triangle sight will be less accurate than a round one.

Peepsight

Posted: Tue Apr 03, 2007 3:54 pm
by Rutty
The really bold might wish to try one of these:

Image

Yes it is real. The irregularities are part of the scanning process.

Rutty

Posted: Tue Apr 03, 2007 5:41 pm
by isuguncoach
We have a "more senior" member of our air rifle club try the triangular frontsight with his air rifle. Was not comfortable, and didn't work well for him. He couldn't get the target to center for him. When I tried to investigate the usage of the sight, most appeared to used by big bore shooters. I would suggest that 10m is too close for the triangular sight to help with vision problems.

J.C.Miller

Posted: Wed Apr 04, 2007 10:29 am
by Padawan
Rutty,

where can you get one of those? that looks interesting enough to try out.

Posted: Wed Apr 04, 2007 2:09 pm
by Rutty
where can you get one of those? that looks interesting enough to try out.
Padawan,

I regret that they are probably no longer in stock. The one I have is at least 50 years old, possibly much older. It was made for the Parker-Hale foresight as fitted to the BSA Martini 12 series rifle that pre-dated the BSA International.

Just to show that there is little new under the sun, the following image comes from the 1963 edition of Fuller's book "Small Bore Target Shooting"

Image

Rgds
Rutty

Posted: Wed Apr 04, 2007 5:45 pm
by Pat McCoy
isuguncoach:

I am a "senior" shooter (60), and going to the triangle aperture at 10M improved my scores about 5%.

I do have an astigmatism, as well as start of a cataract. I think the extra light allowed by the triangle over any circular aperture accounts for the increase for me.

I am also going to go to a larger adjustable rear aperture this year. currently can only get to 1.6, and think more light will again help (probably temporarily).

Triangle fore sights

Posted: Thu Apr 05, 2007 2:30 am
by peepsight
Hi Pat

I'm 63 and moving over to the triangle fore sight gave me a less distorted sight picture.

The theory [and it does work] is that the 3 straight lines that make up a triangle do not distort or bend as a circular one can especially if you suffer from slight astigmatism. Astigmatisism even when using a prescription shooting lens can make a round foresight oval.

Most sight picture distortion is down to not enough oxygen reaching the eyes focussing muscles, so plenty of breathing before the shot to charge your blood with oxygen works wonders. Read ways of the rifle where this is explained in detail.

I have found that if for example you were using a 4.4 round fore sight a size down say 4.3 or even 4.2 in a triangular sight works well.

The amount of light reaching the eye is important and a variable back sight iris is esentual for achieving a good sight picture.

Anschutz make plastic triangle fore sights in various sizes and colours and they have helped me very much. Give them a try.

Peepsight

Why not a round sight with crosshairs?

Posted: Thu Apr 05, 2007 3:56 am
by RFC
As a neophyte attempting to teach himself 10m offhand air rifle shooting, I have been contemplating the concept of "aim small, miss small. " As one of my warmup exercises, I have been shooting paintballs with remarkable accuracy. I figure the diameter of the paintball plus the effective diameter of the pellet is about the equivalent of the 7 ring. However, when I move back to the International 10m, my groups open up. Given my approach, right or wrong, I would benefit from a circle insert with a more defined centerpoint.