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Rifle - Front sight aperture & Ring thickness - Survey

Posted: Wed Apr 06, 2005 8:41 am
by Raj
I would like to know some of the front sight aperture diameter and the ring thickness being used by rifle shooters for the 10M Air Rifle. I use 4.0 dia. with a ring thickness of 1.2 - I have progessed from 4.4/1.2. I have astigmatizm and wear Champion shooting glasses to help me with the sighting.

The band of light between the aperture ring and the target is critical for aiming / proper sight picture - With larger band, you have less tiring of the eye and ease in concentration while aiming but the tradeoff is that you cannot achieve a refined sight picture as with a smaller aperture.

With smaller aperture there is difficulty in concentration and target wobble touching the sides of the ring - unconsciously makes you to 'force' the opposite movement of the wobble. WIth the smaller aperture ring, the target appears to be larger and the sight picture can be better 'defined' for shot release.

In conclusion, the size of the aperture is a personal preference based on the health of the eyes of the shooter. However, there is a trade-off between comfort in sighting versues precision of the sight picture - I am trying to determine this. I would like to know what sizes others are using and what led them to decide on that particular size.

My other question is, do you change the aperture size in a match based on lighting condition and on the tiredness of your eyes during the course of the match.

Any feedback is greatly appreciated.

Thanks,

Raj

Posted: Wed Apr 06, 2005 2:02 pm
by Mickyfriend
Shoot Smallbore prone 50m using front sight with an inner diameter of 4.0mm, ring width 1.2mm, sight line 83 cm from diopter to front sight.

Micky

Front insert

Posted: Thu Apr 07, 2005 1:42 am
by Albert
I shoot small bore 50m and use a ring insert of 3.9; ring thickness unknown. (aprox the standard diameter I think). In 10m air rifle I seem to be differnt from all others and use a insert of aprox. 5.0
It gives me the same ratio as with small bore so the sigtpicture looks the same.
for more info you can contact JP OƇonnor who has done a (prelimenary) study on frontsight insert diameters and distance of target and distance of insert to eye.
Diameter is changed with lighting intensity (sun/cloudy).
Another thing I found was that the amount of area that is covered by the diopter (the area surrounding the peepsight hole) is of great influence on the abillity to keep the eye concentrated on the sightpicture. When the couvering area is to small, the eye is drawn to the light surrounding the diopter. When the couvering (dark) area is to large, the dark area dominates and distractes the eye as well. Only when the amount of couvering area and the light surrounding it are balanced just right, my eye is 'drawn' tot the peepsight hole. Therefore the distance eye-diopter (in my case) is also determined by the amount of surrounding light, usung a variable peepsight.

good luck.
Albert (The Netherlands)

Re: Rifle - Front sight aperture & Ring thickness - Surv

Posted: Thu Apr 07, 2005 6:28 am
by JeroenH
Raj wrote:I would like to know some of the front sight aperture diameter and the ring thickness being used by rifle shooters for the 10M Air Rifle. ...
In addition to front sight aperture diameter, I think you should also look at distance of the aperture from the eye. Putting the aperture closer to the eye has the same effect as increasing the diameter: you get a wider band of white.

Personally, I am using a fixed 4.0 mm diameter, 1 mm thickness ring, at about 77 cm from the rear aperture.

Regards
Jeroen

relation front insert to opening rear aperture

Posted: Thu Apr 07, 2005 7:24 am
by Albert
Hallo Jeroen,
What is your ratio (aprox.) between the diameter of frontsight insert, the frontsight tunnel and/or the rearsight opening?
The inside diam. of my front insert = 2.2 the bullseys diameter. This gives a very steady sightpicture for me. I measured an eye-rearsight distance of 75 mm in my situation.

Groetjes, Albert