Originally Posted by RobF
Oh I see. Yes it's the optics that move and you dial the wrong range.
I get that with mine, trust the scope dial accordingly, everything bang on line all year round.
The only other scope to do that was a 94 Tasco mark1.
Considering the number of lenses in the scope each of which has to focus at a fixed point, the temp expansion on length will have an effect. Some will vary more than others of same make especially if tops out to focus at a closer range whereby the focus may become cammy. A little expansion in length can be massive at the higher ranges. In other words the focus at top end usually requires less movement than short range and will be in a different place. Not so much with the rack and pinion types.