Apature sights

[Bob Thompson]

I have just acquired a new Sharps long range target rifle in .45-70 which I really love but am having trouble with the rear apature sight. My eyes are fairly normal with a slight lean toward far sightedness. My age has me needing a slight correction for seeing small objects at close range ie. reading a micrometer.However I don't need glasses for shooting. My problem is when looking through the apature rear sight I see what looks like spider webbing. I have examined the apature under a magnifying glass and it is perfectly clear. Have any of you bullseye shooters or anyone shooting with apature sights ever come across this problem or do you think it is a personal problem with my eyes. Also I now understand the inherant accuracy using black powder, in my case Pyrodex, as this rifle has shot a 3/4 inch group at 100 yds. even with this sighting problem. Shooting my M-1 Garand with a larger apature I don't see these line like things. I think I need to keep the small apature approximately .040 for centering the front sight insuring long range accuracy. Does anyone have any ideas whats up. Thanks much, Bob.

 

[Mal H]

Bob,
What you described is very common with small apertures. It is caused by diffraction, especially in low light conditions. .040 is an extremely small aperture, used for really fine target shooting and only under ideal conditions. You might want to try one around .1" and see if it really makes any difference in your accuracy. You'ld be surprised how accurately you can aim even with a large aperture. The human eye and brain are very well adapted to centering an object within a circle. I'll wager you won't see any negative effects and you'll be able to see the target much clearer.

 

[Bob Thompson]

Thanks much Mal H for the timely info. I am ordering another eyecup apature to be able to drill it out and keep the small apature for really close target shooting as you suggested. I believe you are completely correct as larger apatures are not a problem for me and my Garand is very accutate with about a .125 or larger hole. Thanks again, Bob