Sight picture resolution woes

[Weinstein]

I'm having sight picture issues and hope someone can be of assistance.

When I center the front aperture, the bull goes out of focus to the point of becoming difficult to center. The front aperture also becomes somewhat distorted, but to a lesser degree than the bull.

When I hold the front aperture at the bottom of the sight picture, the bull springs into perfect resolution, along with the front aperture, which becomes almost startlingly crisp.

I have experimented with head position, eye relief, cheekpiece height and lateral adjustment, front and rear aperture diameter, and buttplate height. None of this seemed to matter much.

I'm 38, (non-Presbyopic for now) wear contact lenses for astigmatism and farsightedness, and my OD tells me I'm 20/20 corrected. With the type of lenses I am wearing now, per my OD the exact position of the lens or even rotation of the lens have little effect on acuity.

I also have rifle shooting glasses with a .25 diopter lens, which improves things a lot... with my unusual "low" sight picture. Likewise a .50 diopter lens is too strong, and fails to remedy my situation.

Here is a crude representation of my clearest sight picture, sorry for the poor quality. This is not meant to be exact, just to show how I have to hold for the crispest possible sight picture:

Low front aperture, bull appears crisp and front aperture in focus:


Cheekpiece height issues have been identified as a likely source of this trouble by my mentor, and I continue to fiddle with that part of the equation. Unfortunately adjusting this variable has not been a cure all.

So... is there something in this mess anyone can put a finger on? Or do I just keep holding the front aperture low and call it good? I'm really hoping this is something someone has seen before, and managed to fix.

Thanks for any assistance you can provide.

[WarWagon]

Does you use any lenses or filters in the rear aperture?

Offhand, this sounds to me like an issue with the astigmatism.

[Weinstein]

No lenses in the rear aperture, just the one in my shooting glasses. There are color filters in the aperture, but I've not been using them.

You raise a good point about the astigmatism, although my contact lenses supposedly correct it. I will raise the issue with my OD when I see him for a re-check next week.

[Shooting Kiwi]

What happens when you try another (mentor's?) rifle? What happens when your mentor tries your rifle? Can you pin down this problem to your rifle's sights or yourself?

Have you carefully checked your rear sight aperture for roundness, concentricity and spotless cleanliness?

[Weinstein]

Kiwi, damn good suggestions, thank you. Honestly I've not tried another's rifle, nor have I had another try mine.

My sights appear concentric and are spotless.

I suspect the problem lies with me, I just need to follow your advice and start eliminating potential variables scientifically.

[WarWagon]

I would also advise sighting in with the rifle high on a bench rest. In other words, have your head as straight as possible looking through the rear iris, not canted forward or backwards, causing you to roll your eyes at all. This will help to rule out some of the eye-related possibilities.

[Pat McCoy]

According to the attached file, you shouldn't worry about it.

[robf]

this happens to me as well

i have a lens as well corrected for astigmatism, however another shooter i know has a problem and doesnt have astigmatism or corrective lenses.

it's happened to us both on prone and 10m, with different sights setups.

as yet, just replacing the head seems to be the only cure.

[Weinstein]

Thanks all, I intend to post again when this issue is solved.

[Guest]

Yesterday my rifle, glasses, and eyeball had a chance to get together with the kind fellow who has been mentoring me, and helping me get my feces cohesive, so to speak.

I must admit that it was me who was messed up, not my rifle.

First thing to be corrected was the eye-wire on my shooting glasses, which has now been bent to align properly with my eye when in shooting position.

Also severely tweaked were length of pull (with spacers) cheekpiece (via spacers and lateral adjustment) handstop position (to compensate for the l.o.p. adjustment) and my own mis-adjustment of my sling.

So, with the exception of my contact lenses (which still sit so high on my corneas, I can visualize the glare off the base curve just sitting here typing) I am now almost perfectly aligned with my sights, and it's made a tremendous difference.

Once I get my lenses figured out, and fine tune the cheekpiece spacers, I'll be in like Flynn.

I guess the moral of the story is that without a mentor, coach, instructor, or seasoned shooter who knows what the hell they are doing, new shooters are potentially lost, adrift at sea so to speak, with no real way to know what to buy, how to adjust it, or how to correct their own errors.

Thanks again to everyone who contributed advice.