Issues with Palma / Match rifle / Fullbore sighting picture

[bushyfromoz]

Im an aussie, i shoot fullbore (similar to palma) in australia for about 18 months now and have constantly had issues with losing sighting pictures several shots into a string. The issue is not always present, and is at times absent for weeks on end. There does not seem to be any consistant cause for it such as tiredness or changing light conditions, but it annoys me to no end. Im kinda hoping some match rifle or palma shooters may be able to give me some advice (other than see an optometrist - there are non here that deal with shooting sports)

The issue is that i start a match (2 sighters + 10 scoring shots) i start with a good sighting image, clear ring definition and an ok aiming mark. I get 3 or 4, sometime 5 shots into a string and all of a sudden when i place the aiming mark into the ring the aiming mark tturns into a indefinable mess of grey and the ring becomes distorted. i also get excessive light bleeding into the ring. When i move the ring off the aiming mark the two become clear again.

Ive tried changing ring size, filters, polarising lenses, sighting radius changes, changes in position of head angle, all with no effect.

Does anyone have any idea what is going on?? My educated guess its eye fatigue, but its not consistant in when it will happen or under what conditions it occurrs.

Thanks in advance

 

[Martin52]

Re: Issues with Pama sighting picture

Could be a few causes:

Relax the eye between each shot, look away into the distance for 15-12 seconds, then don't look too long at the target, get the shot away within 5-10 seconds.
Ensure adequate hydration.
Excessive pressure on the cheek piece. If you think this is likely, try lowering the cheek pieces slightly to ease the pressure.
If your eyes are particularly sensitive, protect them from the wind (sunglasses, regular glasses) whilst waiting to go to the line, use safetey glasses when shooting eg Uvex.
Use eye drops, but at least 15 minutes prior to shooting to allow time to clear focus.
Rinse your "shooting eye" in warm water in an eye bath, available from your local pharmacy. You can do this at home before heading out.
Check your rear aperture, hot dry clear days - I use .8 - .9, anything over 1.2 goes grey for me.

I do recommend an eye check, you don't necessarily need an opto with shooting experience, you may find you need correction, including possibly for astigmatism.

Bryan Smith based in Brisbane is very good, he is one of the few opto's with shooting experience, he gets to Sydney regularly, contactable via QRA, Belmont.


Hope this helps.

Martin

 

[bushyfromoz]

thanks martin.

i had thought about the astigmatism, but i thought that the visual disturbance from astigmatism would always be present?

 

[wapiti25]

Make sure to breath deep to get lots of oxy. between shots.

 

[FroggyOne2]

My first thought is, "Do you shoot with both eyes open or with the non aiming eye closed?" If your closing the non aiming eye during the sighting period, your eye your using to sight with will become fatigued. This goes the same for F-Class too guys. Learn to shoot with both eyes open.

 

[bushyfromoz]

thanks for the replies

I shoot with both eyes open
No amount of breathing between shots changes the sighting picture

 

[Martin52]

i had thought about the astigmatism, but i thought that the visual disturbance from astigmatism would always be present?

I have an astigmatism in my right eye, for most everyday activities it's barley noticeable however when shooting, a rear correcting lens is essential because the front eagle eye magnifies the bull and with it magnifies the effect of the astigmatism. It would get worse if I then open the rear aperture up by more than 1.0 - 1.2, aiming black would become greyed out and blurry. Without the rear lens, the eye works hard to try and correct the focus, a job that is harder with the eagle eye up front and gets progressively harder during the string - possible why you experience this after 4-5 shots, the eye can deal with the problem, but only up to a point.

For example, using a distance prescription of say 1.0 x 1.0 x 150 (axis of astigmatism), you would deduct 0.25 (being half the 0.5 eagle eye) so your rear lens script is 0.75 x 1.0 x 150. This should give you a clear front ring whilst making the aiming black as sharp as possible.

A regular eye check at your local opto will give you the starting prescription.

Martin


Just checked my own script - distance script is -0.5 x -0.5 x150 axis. My rear correcting lens is -0.75 x -0.5 x 150 (I use a 0.5 e/e in the front sight).

 

[Erud]

I had a problem similar to what you are describing for a couple of matches last year after making some changes to my Palma rifle that I thought were minor. After a personal worst score in a Palma match, the guy who was scoring for me (a local guru who's taught me more than anyone else) asked why I had moved my rear sight so far forward. Well, I didn't even realize that I had. Did some experimenting on the line after the match was over and moving it back towards my eye brought the target back into clear view. When I got home I compared it to my main match rifle that I shoot very comfortably and the Palma rifle's sight was now in the same spot. Before it was probably close to an inch too far forward. Really glad he pointed it out to me. I'm an experienced shooter, but sometimes it's easy to miss(or forget about) little things I should know. I probably would not have figured it out on my own for a good while.

Might not be the same as what you have going on, but the symptoms sound similar, so maybe it's worth a look.

Good luck,
Erik

 

[jr600yd]

Sounds like eye strain to me. Try this. After each shot keep both eyes open and look at something far away (tree line, targets ?) Then something up close (score book, mat, ?). Repeat several times. This exercise forces the eyes to refocus. It won't stop eye strain but it will delay it and reduce its effect.