Rifle Scopes Return To Zero Side Effect

[ShtrRdy]

I've got a Nikon Monarch that I was trying out a "Return to Zero" test. I shot a couple shots at zero, then cranked up on the Elevation Turret, and then returned to zero, and fired another shot. Elevation wise, (vertical direction), the last shot was very close to the first two. However, the last shot was about 0.75" to the right of the first two.

Poking around on the internet I found a few posts that show the same sort of thing. Where there is an offset perpendicular to the direction being moved.
http://bulletin.accurateshooter.com/2008/06/sightron-siii-8-32x56-scope-test-part-ii/

http://www.snipersparadise.com/bits-o-wi...mil-dot-reticle

http://www.702shooter.com/product-reviews/osprey-international-ta41650mdg/

Can anyone explain what is happening here?

 

[KNIGHT11B4]

Re: Return To Zero Side Effect

Did you just attempt the test once? If so, not much can be determined when you consider shooter error is very possible.

I would recommend repeating the test multiple times, if you haven't already done this.

 

[ShtrRdy]

Re: Return To Zero Side Effect

I did the test twice.

 

[KNIGHT11B4]

Re: Return To Zero Side Effect

Both times the shots went .75 Right?

Did you zero, crank, return to zero, shoot, crank, return to zero, shoot?

 

[dieselten]

Re: Return To Zero Side Effect

how accurate is your rifle? never had a flier??

 

[bricktop]

Re: Return To Zero Side Effect

Are you holding the rifle perfectly level each time?

 

[ShtrRdy]

Re: Return To Zero Side Effect

The test was performed on two different days.

The rifle, (and me), will shoot 0.5" groups at 100 yds. It is very consistent. This is a .223 rifle.

I shoot the rifle off a bipod on the front and a sandbag on the back. I'm pretty sure the rifle is very close to level.

 

[KNIGHT11B4]

Re: Return To Zero Side Effect

Is the optic slipping zero each time you spin it up/down. Meaning, if you were to do it 3 times would you be 2.25 right?

 

[slowr1der]

Re: Return To Zero Side Effect

I had a similar issue with my Monarch. At first I thought it tracked well as I did a box test at 100 yards sand it passed with flying colors. I made adjustments a few times and it always came back to zero. However, I then took it out to the field a few times and never shot 100 yards again. I was making plenty of adjustments both times. After those two trips I hit the 100 yard range again and when I did, the rifle was shooting a few inches to the right. I sighted it back in and did another box test and it seemed to pass again. The only thing I think that could be happening is I think it might be moving just a hair each time so that I don't notice it when performing a box test, but after making repeated adjustments over and over again I think it's starting to show up as an issue.

My solution for this was to replace it with a SWFA SS and put this on a hunting rifle that I don't need to make adjustments with in the field.

 

[ShtrRdy]

Re: Return To Zero Side Effect

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: KNIGHT11B4</div><div class="ubbcode-body">Is the optic slipping zero each time you spin it up/down. Meaning, if you were to do it 3 times would you be 2.25 right? </div></div>

I don't know. Maybe it's doing something like that?

 

[VKC]

Re: Return To Zero Side Effect

Are you at the end or extremes for the turrets turn? If so, some scopes down track as well at the ends because of excessive or too little spring tension.

 

[ShtrRdy]

Re: Return To Zero Side Effect

The elevation and windage adjustments aren't at the end of their travel.

What I'm asking about is if anyone knows why there would be an offset in the perpendicular direction after moving off zero and back again. The three links I included in the original post show the same sort of effect that others experienced.

If someone understands the internals of a scope operation they might be able to come up with a reason why a scope does this.

 

[Ballistic308]

Re: Return To Zero Side Effect

When returning to zero go past the zero mark a couple of clicks and then come up to your zero, this will remove the lash by always loading tension onto the same thread surface. If this works for you all you have to remember is to make sure you go past and then come up every time.

I've seen several Nikons with this issue, my Buckmark is one of them...it a .22lr scope now.

 

[TallShot]

Re: Return To Zero Side Effect

I have a Leupy 4.5-14 M1 turrets that started doing something similar; that I sent back to Leupold a couple weeks ago.

It's probably 10 years old, and has seen it's share of rough treatment, so, we'll see when it comes back.