View Single Post
Old 4th August 2010, 09:58 AM
JTK's Avatar
JTK JTK is offline
Join Date: May 2010
Location: Pretoria - South Africa
Posts: 85

Originally Posted by L-S-R View Post
It is the sidewheel parallax mechnism that is being affected. The POI is not effected.
Snipers have spotters, laser rangefinders, satelite co-ordinates, intelligence info for exact weather conditions etc.
For us the parralax mechanism determines the range, if this shifts in temperature we either under range and miss low or over range and miss high. E.G. a 55yrd target measured with tape in 30degrees, with scope you range it 59yrds dial accordingly and dink high, if you had used your 55 yrd setting you would have the correct elevation for the target.

In a really bad case both the gun and the scope are affected by temperature, then you are really in trouble Heat can cause guns to run faster and cold slower which would only exaggerate your difficulties in varying temperatures with a scope thats parralax mechanism varies with temp change.

This is of course IMO and there will be other more knowledgeable people along to help.
Hi, it is not only the mechanism that gets affected. The light refraction (some scopes worse than others) can also cause this to happen. Have a look at the attached pics. This scope was mounted on a table in an airconditioned office. The scope was not touched. A tripod was set up behind the scope with the camera on it. The poi shift was purely relating to the direction the sun is shining from on the target Btw the manufacturer is replacing this scope (new nikko) as it is not supposed to happen. I believe it happens in all scopes. some worse than others. This makes it important to get your scope optically zero'ed imo.
Attached Images
File Type: jpg D2 08h39.JPG (9.5 KB, 24 views)
File Type: jpg D2 11h26.JPG (7.8 KB, 23 views)
File Type: jpg D2 13h55.JPG (9.3 KB, 23 views)
Reply With Quote