Does my zero change with a power change on a variable scope?

[chkunz]

I would like to know if a power change on a variable power scope changes my zero.

 

[Dud]

It shouldn't.

 

[swd]

It can and it’s not all that uncommon.

 

[muleman69]

I would like to know if a power change on a variable power scope changes my zero.

Good question hopefully not, maybe in lower end scopes? Hopefully the experts will chime in .

 

[Rogmay]

It shouldn’t, if mine ever did I’d send it in to get fixed. On say my 6.5-20, the POI at 100 yards is the same on 6.5x as it is on 20x, if thats what you’re asking.

 

[Vodoun daVinci]

I'm running an Athlon Argos BTR 10-40X56 and my zero does not change from 10 to 40. If it does I can't see it at 100 yards. That said I have heard of scopes that do/will change zero at various power/zoom but I have not owned one that did. I'd think that maybe the scope isn't level or mounted correctly if I had this issue.

VooDoo

 

[dmoran]

It's not uncommon for there to be some POI change with large power variables across there range of power (even with high dollar scopes). It takes a "scope checker" to find out the truth and the amount. At 100yds judging by shot placement, it would be hard to see or call anything less then bullet diameter, with out a scope checker.

Not using a scope-checker would be a similar scenario of the guy who will say there barrel is clean, with out looking down it with a bore-scope.

 

[Bill K]

It could, but it will be so slight you really will not notice it. Your own movement will make more of a difference actually.

 

[coldboreshot]

I would like to know if a power change on a variable power scope changes my zero.

Something I stumbled upon a while back...Make sure your eyepiece focus is set to the best of your vision. This can interact with the parallax adjustment of the scope causing the POA to be off. Even if you know "for sure" that the parallax is set correctly, the eye focus adjustment can still inhibit. A LONG TIME benchrester confirmed this. Also, conduct a box test at both power ratio extremes. High and low. Should be the same. Damaged erectors and internals of the scope can force the Out-of-line movement and cause slight shift in the POA. Hope this helps.

 

[284winner]

Something I stumbled upon a while back...Make sure your eyepiece focus is set to the best of your vision. This can interact with the parallax adjustment of the scope causing the POA to be off. Even if you know "for sure" that the parallax is set correctly, the eye focus adjustment can still inhibit. A LONG TIME benchrester confirmed this. Also, conduct a box test at both power ratio extremes. High and low. Should be the same. Damaged erectors and internals of the scope can force the Out-of-line movement and cause slight shift in the POA. Hope this helps.

100% Dead On. Very good advice as that exact process can attribute to less than perfect scope accuracy if not tuned to the users eye. I faced that issue in the past and self learned what needed to be done on some scopes.

 

[Prose]

I would like to know if a power change on a variable power scope changes my zero.

Yes, if your scope is broken.

 

[coldboreshot]

It could, but it will be so slight you really will not notice it. Your own movement will make more of a difference actually.

Only if the parallax and eyepiece focus are not set properly. You could have someone who is a human bobble-head but that cross hair should not move from the POA when looking down the tube.

 

[pdog2225]

I would like to know if a power change on a variable power scope changes my zero.

I this happened on a 6 x 24 x 44 scope I bought new. I put it on a rem 541T 22 long rifle. When I shot it at 180yds the POI would change about 7ft to 8ft as I changed the power from 6 to 24. At first I could not figure it out, so I had other shooters try it. They had the same results. I returned it. I think the erector tube was not moving back and forth in a straight line. So now if I have a question about a scope power change I put it on a 22LR and shoot it....

 

[Turbulent Turtle]

I have seen thins on my Nightforce NSX 12-42X56 scope. After I replaced it with a March on my F-TR rifle, I mounted the NSX on a .22LR to have some fun at local Rimfire Benchrest matches. When I first installed the scope on the .22 rifle, I finally got it on paper at 50 yards (it doesn't focus down really well, but it was enough,) at 12X. I cranked it up to 42 and established a zero. It shot it at a few matches. Then one day, I removed it from the rifle and used it on something else for a while.

When the rimfire benchrest season started up again, I moved the scope back onto the 22LR and zeroed it at 12X and started shooting a match. I realized that I was at 12X and moved the magnification to 42X. My shots started going high about 1 inch. That was strange. I dialed back down to 12X and the zero came back. Zoom back out to 42X and the one inch high comes right back. That's like 2 MOA of change.

In F-TR matches I always ran it at max magnification, but in retrospect, if I had even dialed down for some reason, that would have been interesting, to say the least. Just something to be aware of.

 

[X-Caveman]

I would like to know if a power change on a variable power scope changes my zero.

Yes, it can. It's quite common, actually. Good news, is it's easy to test with a scope checker. You don't even need to go to the range or fire a shot. Put two scopes on the checker. Dial out the parallax on both at the same target. Crank the W & E knobs so the reticles are zeroed on the same POA (as close a the click resolution will allow). Change magnification on one scope only. Check to see if the reticles still co-witness. Many competitors at the highest levels check this as part of their evaluation of a scope (no, I don't claim to be one). If it moves a little, the scope is most likely otherwise serviceable. You just know not to touch the magnification mid string. I'd argue that it's worth checking on a LR hunting scope, as well.

 

[Curmudgeon]

Shoot your 600 benchrest match and change magnification during your score string and see what happens. No one I shoot with will change magnification during score target and these are all high end scopes.

 

[Hermantk]

Shoot your 600 benchrest match and change magnification during your score string and see what happens. No one I shoot with will change magnification during score target and these are all high end scopes.

Unfortunately, the sudden arrival of mirage may make it necessary to reduce magnification in order to see the target.. This probably happened to me half a dozen times last season. As you can imagine, if the POA changed with the change in magnification, I would have been out of the match. If your scope is properly adjusted (parallax) and the POA changes with a change of magnification, then something is wrong, (manufacturing error? damage?) And doing a box test has nothing to do with this issue. You should either send it back for service or replace it.

 

[Lefty Trigger]

Here's the thing,.. its not supposed to!

 

[Mr.Knowit all]

Yes, if your scope is broken.

lol Sorry, but that was funny.

The center (zero) should never change in a FFP or SFP but if you are using the reticle for hold over shots and you have a SFP you will be VERY off

 

[Straightshooter1]

I would like to know if a power change on a variable power scope changes my zero.

I'd say a powder change can change one's zero for any scope as it depends on the change in velocity that the powder produces. If the velocity is the same, then NO, it doesn't. But if there's a significant change in velocity, then YES, the zero will need changing as the POI has in relation to the zero one had set. For example, higher velocity results in lower POI.