bruce moulds wrote:rod,
how much freebore is required for the 183 copperheads in a 284 chamber?
bruce.
I am not sure yet as I hope to receive my Copperheads soon. Their bearing surface is a little shorter than the Berger 180 VLDs and Hybrids.
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bruce moulds wrote:rod,
how much freebore is required for the 183 copperheads in a 284 chamber?
bruce.
bruce moulds wrote:graham,
do you have astigmatism?
I do.
my optician told me that you can refocus a scope to suit glasses for your eyes.
bruce.
pjifl wrote:Technically, eyepiece and spectacles have no effect on Parallax. Parallax adjustment takes place in front of the Graticule. But any poorly corrected astigmatism usually results in reduced resolution across the target in one specific direction.
I am beginning to wonder if the progressive lenses becoming more common in spectacles these days could be a problem for scope users. I have no experience of them.
so short answer Pete is possibly “ Yes” it could have an effect?pjifl wrote:Focusing the Graticule for the eye is via the eyepiece and is done first. And ideally this is best done with no target image in the scope - just a bright background. Unfortunately it changes with your state of health and hydration and if you have been reading a lot before the shoot.
If for some reason this is not done properly first, and you later adjust the side for best clarity rather than parallax, you can introduce some parallax in error.
It is possible that because of poorly corrected astigmatism you may be focusing the graticule with eyepiece poorly to begin with. My concern is that with progressive lenses, something similar may happen but that is just a sneaking suspicion in my mind. I know that because of falling public demand, many spectacle lens makers will not make simple lenses these days and Opticians find it hard to have them sourced and will push you towards progressive lenses.
Strangely enough, it is young shooters who are at most risk of ending up with parallax problems with a riflescope. Their eye is so flexible its focusing muscles can change in such a way that when they initially focus the eyepiece and when they actually shoot, their eye falls into a different setting.
Perhaps this should go in the new thread - it developed in this thread almost accidentally.
I think it is far more important than most think.
BTW, carefully centering the eye behind the scope eliminates any parallax problems even with a poorly adjusted scope. It is more important than getting a full wide view in the eyepiece and you can always fall back onto this.
If you have very slight astigmatism, as long as you use very high magnification, seen astigmatism actually has less of an effect and more or less 'goes away' with no spectacles. Apart from protection, you may actually be better off using no spectacles. Long and Short focus is perfectly compensated by refocusing the eyepiece as long as it has sufficient range.
With people with moderate astigmatism, it is hardly an option although you may be surprised. I have moderate astigmatism and am envious of those without any.
The classic way to detect astigmatism is to view a well printed circle without spectacles. At different distances from the eye, different parts of the circle will appear in better focus. Or view a well printed line directly with the eye. By rotating the line, it will go in and out of focus.
Fascinating subject and since people are different, there is no simplistic cure.
Rich4 wrote:That is exactly my problem, many variables to diagnose without experience, training alone can be frustrating at times, I also would like to thank Peter for his generosity with his knowledge and time and many others on this forum giving information freely, I have been reading for ages and there’s still more to go, so a big thank you to all
Pablolig wrote:Hi guys,
What about the Lapua Scenar L 180 gr???
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