Rifle Scopes Eye relief increases as the magnification goes up?

[AznTactical]

Picked up a brand new Bushnell AR 4.5-18x40 for my daughter's 1st AR and I noticed the eye relief distanced increased almost an inch from low mag to high magnification. I've owned almost 2 dozen scopes and this "growing eye relief" is a first for me. This is not normal right?


Even did a quick box test of 5 shots each at 8 moa up and 8 moa left then 16 moa down, 16 moa right, 16 moa up and back to zero at 4.5X magnification and repeated my test again at 18X magnification. The return to zero's grouping was about .75" to the right of the original zero grouping but overall I'm quite happy with the results for a <$140 scope. The warmish/hot barrel might of been a factor so I'll be re-testing it again but allowing more time to allow the barrel to cool off.

 

[gconnoyer]

Set the eye relief/scope position on max magnification.

 

[AznTactical]

Set the eye relief/scope position on max magnification.

Sorry, forgot to include this info:
-Eye relief at 4.5X was just under 4".
-Eye relief at 18X was right around 4.8".
-Bushnell's specs are 3.7".

I had the wife measure my eye relief with a tape measure.

For comparison sakes while using my Vortex Razor AMG & Gen II Razor 4.5-27x56:
-Eye relief at minimum for both scopes was just over 4".
-Eye relief at max for both scopes was 3.8".

 

[ShtrRdy]

The diopter adjustment may be off. I learned recently that it's important to perform the diopter adjustment a certain way. It makes a difference.

Is there any parallax adjustment on that model?

 

[AznTactical]

The diopter adjustment may be off. I learned recently that it's important to perform the diopter adjustment a certain way. It makes a difference.

Is there any parallax adjustment on that model?

The diopter is adjusted to my eye's and parallax markings matches the 100,200 & 300 yrd targets.

 

[FishDr]

Interested in this myself. I have to adjust diopter on my scopes a bit different than most (due to an astigmatism?). I’ve noticed that on my scopes the parallax adjustment never seems to match the dial. When adjusted for others, the dial matches much closer. Is this a normal phenomenon … I.e. does lengthening the diopter adjustment cause the parallax to focus at a different location in the dial?

 

[Hollywood 6mm]

The diopter adjustment may be off. I learned recently that it's important to perform the diopter adjustment a certain way. It makes a difference.

Is there any parallax adjustment on that model?

Our of curiosity, what's the process you started following?

 

[ShtrRdy]

So, my situation was with a Nightforce 2.5-10x42 NXS model in which I thought the parallax adjustment wasn't working properly. I called Nightforce and they walked me through the steps for this particular model. I don't have the notes handy but I think it was to set the power ring to maximum magnification, set the parallax to infinity, and then look through the scope at a blank wall 20' - 25' away. Then turn the diopter adjustment until the reticle was in crisp focus. While making these adjustments look away for several seconds and then look into the scope searching for that crispy focused reticle. The reason you need to look away and then look back is because the eye will adjust to make up the difference when it can.

 

[Hollywood 6mm]

So, my situation was with a Nightforce 2.5-10x42 NXS model in which I thought the parallax adjustment wasn't working properly. I called Nightforce and they walked me through the steps for this particular model. I don't have the notes handy but I think it was to set the power ring to maximum magnification, set the parallax to infinity, and then look through the scope at a blank wall 20' - 25' away. Then turn the diopter adjustment until the reticle was in crisp focus. While making these adjustments look away for several seconds and then look into the scope searching for that crispy focused reticle. The reason you need to look away and then look back is because the eye will adjust to make up the difference when it can.

That's the same process I have used for a while now. I mainly wanted to know if there was another way of doing it I hadn't heard of.

 

[FishDr]

Same way I do it except I look at the sky or something white a very long ways away.

 

[spife7980]

Many scopes do that, even my leupold vxIII does it. Where you need to place your head at minimum magnification is closer to the scope that at max magnification.

I figure its just an aspect of the design that they didnt consider at its price point.