Scope Power

[Cameron Mc]

Was told at a shoot by a fellow shooter to wind down the scope power at longer ranges to minimise elevation troubles.
Has anyone heard of this. I shoot my scopes on 24x
Peter Smith....... I would be interested to hear your comments.

Cameron

[Simon C]

May be related to mirage effect (image shift) at greater magnification.....backing off reduces the effect of mirage on image clarity but Im not sure if it changes the image shift though.

[pjifl]

I believe the benefits of reducing magnification in severe mirage is extremely complex and usually exagerrated.

It depends on your aiming technique. If you are a knob twiddler and always aim on centre it has some validity. But if you always aim on centre even a 1X (yes one) scope will achieve 1/10 min precision with care so 10x or 15x is plenty. Remhtember tha limiting accuracy of peep sights is about 1/10 min. Hard to believe but true with good eyesight.

BUT I want a scope to do a lot more than simply aim. Like estimate shot error, check the value of a shot, see and estimate wind via mirage, and allow accurate aimoff. On the champ target you can aim off even at lower power better because it is linear - which is a major reason we should insist on it.

If you think about it, if there is some error being introduced by higher power which causes aiming at the very centre to be different from aiming at a larger portion then the target will appear to be distorted at times. If it is seriously distorted - and this view is varying - then maybe the lower power is better. The other approach is to simply use the brain to average out the target position in the mind.

For what it is worth I believe 20x is the minimum I want to ever use and would rather see any optical convulsions than be ignorant of them. My usual is 25x (fixed) and I consider at the shorter ranges there is nothing wrong with 32x.

I once subscribed to the theory of lower power in severe mirage. But after getting throughly whipped all the way out to 1000 by a fellow using a fixed 32x (or was it 36) scope in extreme mirage revised my ideas.

To some extent it is a personal thing. But do consider all the other factors as well.

For me - a significant factor is that I have spent a lifetime shooting with a spotting scope of 20-25 xand believe I am better able to read mirage at this power.

peter Smith.

[Cameron Mc]

I believe the benefits of reducing magnification in severe mirage is extremely complex and usually exagerrated.
Remember the limiting accuracy of peep sights is about 1/10 min. Hard to believe but true with good eyesight.
BUT I want a scope to do a lot more than simply aim. Like estimate shot error, check the value of a shot, see and estimate wind via mirage, and allow accurate aimoff.
peter Smith.

Thanks Pete. I totally agree. It is truly amazing how accurate peeps can be, but like you say.....good eyesight. I find with 24x and a very fine cross and dot reticle I can obtain a very accurate aim unless mirage is bad. I don,t wind the power down if mirage is bad, when I have tried this, the mirage is still there and the target much smaller to the eye. I guess it is a personal thing.

Cameron

[AlanF]

There has been some discussion about this on longe-range.com. And as both of you say, the concensus is that what's best for one shooter may not be for another. For me, having the image bouncing around over a large area of the field of view is disconcerting, and in heavy mirage I wind down to as low as 10X. If the mirage is bad enough to cause me to do that, it also means there's plenty of mirage to read at low magnification.

As you are both experienced full-bore shooters, I'd be interested in your opinions (and anyone else's) on an article on 6mmBR.com. Here's a quote from it :

One old rule is never ever shoot in a boil. That's pretty sound advice but how do you tell a boil from mirage that is running straight away or towards you, the answer, practice. While boiling mirage and running mirage look similar they will cause distinctly different movement of the image, one is raising the image and the other is pushing it down.

The full article is at http://www.6mmbr.com/readingmirage.html. I'm not quite sure what to make of it. It seems to emphasise overcoming the distortion caused by mirage rather than using the mirage to estimate wind drift.

Alan

[pjifl]

A bit of waffle here.

Re the accuracy of peep sights, eyesight, and experience - some may be interested in an experiment I once did with a group of about 10 school children - probably av age of 15. About half girls.

Before they actually shot a peep sighted rifle I put them behind a sighting jig which was rested and sighted by moving two micrometers. These moved dial gauges. While the aim was to introduce them to peep sight use, after a subject repeated this about 5 times it was possible to measure their sighted group size.

The results were fascinating. ALL but one could easily achieve 1/2 min groups - most more like 1/4 min. None had any experience of this previously. The exception - it was discovered had poor eyesight and should really have been wearing specs. Achieved about 2 mins which is all bulls on a TR target anyway.

After this I tried it on many more people - many shooters - and every shooter who tried it was better than 1/4 min.


My conclusion - its limited more by eye/muscle/brain coordination than practice or exquisite eyesight. The micrometer drum adjustment seemed to be the secret.

Since this, I have really wondered about doing some F shooting with a peep sight someday.


Another remarkable instance of this was when a group of youngsters were being introduced to some 22 shooting. Shooters had loaned rifles - all had scopes on them except one I had there which was a decent smallbore rifle with peep sights in case there were too many shooters. Of course all the pushy types - mainly boys - got the scoped rifles. One shy girl was left over and had to take the smallbore rifle.

Yep - the results of the shooting were very embarresing to most of the candidates because the smallbore rifle - used by someone who had never used peep sights before (but from a rest) - simply blew all the others away. It was VERY nice to see. After that she stayed with it and would not swap for any of the scoped rifles.

Peter Smith. And yes - I do have a soft spot for peep sights.

[Cameron Mc]

As you are both experienced full-bore shooters, I'd be interested in your opinions (and anyone else's) on an article on 6mmBR.com. Here's a quote from it :

One old rule is never ever shoot in a boil. That's pretty sound advice but how do you tell a boil from mirage that is running straight away or towards you, the answer, practice. While boiling mirage and running mirage look similar they will cause distinctly different movement of the image, one is raising the image and the other is pushing it down.

The full article is at http://www.6mmbr.com/readingmirage.html.
Alan

Alan, I have not read that article, a lot has been written on this subject. From the above quote, one key word should be emphasised....PRACTICE. Following on from practising we have to be dedicated to learning. Ask the other shooters how they are handling the conditions, watch the conditions carefully before shooting, watch others shoot and check their results thru a spotter. There are no secrets and we are all still learning.
I use mirage as a good guide when the wind is light and/or fishtailing. Trying to read mirage in strong winds is usually not a help. In my fullbore days I focussed my spotter approx 50 to 100 yds in front of the target. Now, with a scope I focus on the target. When looking at the mirage I look at it on top of the target frame. For me this gives a clearer picture of what it is doing. I don,t have any hard and fast rules with mirage, there are too many different senario's.... go back to the word PRACTICE. If we have a bad shoot we should try and take something positive away from it and not focus on the negatives. One of the main things I like about this sport is the challenge of beating the conditions. A positive outlook is a must. One shot at a time and don't think about your score while you are shooting. When I first started shooting I used to "listen in" on conversations going on behind me, usually dirty jokes. Now the only thing I here is the scorer.... read CONCENTRATE
One last thing, there is another word that affects us all.....LUCK
Hope this makes sense

Cameron