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Thread: Questions about zero shift

  1. #1
    Sharp Shooter

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    Default Questions about zero shift

    Hi all,

    What do you do, if you find that your zero has shifted (especially the FT shooters)? If, let's say you open a new batch of pellets and the zero is off - do you unscrew the top turret and adjust the zero or redo all the markings on it? Also if you go to the range and the zero is changed due to environmental conditions (e.g. humidity, tempreture, air pressure) - do you aim slightly off the center of target to adjust for that or you re-zero the scope?

    Thanks
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  2. #2
    Inactive Member

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    You've got to re-zero surely, you can't go around aiming a bit off, it's a precision sport!
    Seriously, it's easy enough to alter the few clicks you are likely to be out, as long as you are dealing with a known range. Sunday, I shot a few at a plate at 35 yards, normally 3 clicks for me. I noted to cloverleaf on the plate I needed 16 clicks, I loosened the top turret & turned it back to 3. All the other ranges worked fine after that.
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  3. #3
    Sharp Shooter

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    There should be more than that, I think. If you zero shifts because of pellet batches, may be your entire tragectory will shift slightly. Also, what about environmental changes shifting the zero?
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  4. #4
    Protea Benchrest (Air) Team '08/'10/'11/'13/'15

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    From bright sun light to shade and setting sun changes poi. Then there is mirage that also changes or rather bends the light
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  5. #5
    Protea FT Team '09/'10

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    What's happened to me at a few shoots is also found the turret to be off a couple of clicks - i've zeroed the turret (hitting dead centre at say 10 or 15m), loosened the screws and re-positioned it with the turret value at the "zero" point. Worked perfectly thus far. I fear to think what my scores would have been had i not done this, and against some other shooter's recommendations to leave it alone. Also bear in mind that temp changes, humidity form morning to afternoon also have an effect on this.
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  6. #6
    Protea FT Team '10

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    My opinion......You shouldnt be readjusting your turret with every POI change that you get at every shoot. Ideally you should know your equipment and know how it performs in different conditions. I have seen a POI change on my rifle in the space of a few minutes (as mush as 2 mil dots low out to 25m at 50mag). What happens during a shoot when the weather changes and you have already readjusted you turret to suit the conditions that you started shooting in......
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  7. #7
    Inactive Member

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    I don't like messing with a set up that's working fine & if it was just the conditions of the day, temperature for instance, I'd get on the zero range, note how much drop there was beyond 35 yards & leave it at that. I certainly wouldn't try to alter windage for the conditions, I saw someone do that at a Comp & it wasn't pretty!
    But if the shift is caused by something that you'll be living with for a while like, a equipment or pellet change then you surely have to re-zero, it's no biggy really!
    Pellets are awkward though, the only strategy I can suggest is, when you've found a pellet you can live with, buy enough of that batch that you don't have to keep altering things!
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  8. #8
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    Gary G,
    At 50x mag. those two mills is nothing at 10x mag. Try it, you'll see it is around one fifth of that, which is negligible.
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  9. #9
    Sharp Shooter
    The Professor

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    Quote Originally Posted by NJHS View Post
    From bright sun light to shade and setting sun changes poi.
    No, that alters the range finding results not the poi - so for example if your rifle is zeroed for 30m it is still shooting on at 30m but your scope may be telling you a distance that is off.
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  10. #10
    Sharp Shooter

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    OK, so can we conclude now - if you change pellet batch then re-adjust your zero on the turrents, if the environmental conditions change then aim slightly off center to compensate? Is that good enough?
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  11. #11
    Protea FT Team '07/'08/'09/'10/'11/'12/'13
    National FT Champ '09/'13

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    Swordfish, yes adjust if it is your pellets. But it will be hard to determine that it is indeed the pellets, and not a certain condition causing the poi shift. I have never needed to adjust to a different batch of pellets of the same make. Yes, you get batches that group better than others of the same make, but I havn't noticed a poi shift due to different batches.

    I do not like to adjust on my elevation turret, by loosening it, and mooving it a couple of clicks, unless we are at that time of the year, when we have a season change.

    Normally at this time of the year, where we are now, it is very stable, unless there is a weather front moving in, and even then, you will have a poi shift, but it always moves back to the original settings during the cause of the day.

    I note what my poi shift is, in mil dots at 50 mag, at what distances, and then compensate for it, and try and monitor where my pellet hits. The poi will ALWAYS move back again as the day progresses, and the moment it shifts back to normal, then I use my original settings again.

    This phenomanon, and esspecially inaccurate range finding, is the cause of the most miss shots by the top shots.

    My advice is, to shoot as much as possible in conditions when you will experience poi shifts, and then make a note of what happens, and what you have to do to overcome it, without loosening, and adjusting your turret.
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