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Old 11th March 2013, 07:59 AM
neilL neilL is offline
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Join Date: Mar 2010
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Location: Oxford
Posts: 576

Originally Posted by RobF View Post
Just doing a little research to see if the main trend works with a theory of mine.

Those that see definite scope shift (and not the gun changing power or bending in temp), can I ask what happens to your scope in rising temp and which way the wheel turns.

Ill make it easy. The march seems to underange in higher temps and over range in lower. Ie in high temps a 55 target will read say 52. In low a 55 may range at 58. The wheel turns so that if 55 yds is on the pointer then 45 yd line will be above it on the wheel. Does that make sense?

Interested to see if there is a correlation in wheel direction and shift direction. If there is then I might have a theory to look at something in closer detail. Doubt it will be curable but it might be testable if I can persuade a scope maker to try something.
Hi Rob
On my Leupolds it has been the opposite. i.e. the wheel is the same (55yd on pointer, 45yd above) but when cold the actual distance is below the pointer and at some high temp it is above. I range high to low usually and it appears to be the internals rather than the scope tube temperature so I have to wait a while before the offset catches up with the temp strip. On my 20-50 (PR boosted Leup) the "low temp" switch seems to be at 8C-9C and this WL season has been a PITA as courses have warmed up through the session :-(

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