Scope Optical vs. Mechanical Limits

[Bart B.]

Anyone ever see if the reticle (line of sight) stops moving on target before the adjustment knob reaches its mechanical limit in either direction?

[Jimro]

I've only ever tested a few scopes to their extreme range of adjustment, and I've not run into a situation where the reticle stopped before adjustment bound up.

Adjustment runs out either because the threads are at their max limit, or the internal tube starts hitting the outer tube. Both of those states are independent of light transmission through the scope and therefore position of reticle on some target.

I guess if a scope maker put in a safety stop on the internal tube that didn't coincide with the knob stop you could get that situation. It's also possible that a parallax problem could exist where adjustments don't seem to move the reticle any because the reticle is focused on a different plane than the target.