Sighting in a rifle in the wind

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by sambo3006, Sep 29, 2006.

  1. sambo3006

    sambo3006 Well-Known Member

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    The place that I have access to shoot out to 500 yards seems to almost always have a crosswind for the safe direction to shoot. My question is, if there is no wind and you are sighted in dead on at say 200 yards, is it possible for your reticle to not be centered with the bore so that your shots would "drift" off to the side at longer ranges?
    My scope was fairly close to the center of the windage adjustment when I boresighted at 200 yards and adjusted the Millett rings for windage. I am shooting the 225 gr AB at 3050 fps. The scope is a Burris 4.5-14.
    Can I safely assume that any sideways deviation of my groups at longer ranges is due to wind drift and not the scope? I can't ever seem to get out there in calm conditions.
    I hope that I was clear in what I am asking.
    Thanks in advance,
    Sam
     
  2. royinidaho

    royinidaho Writers Guild

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    Wind is a real pain.......

    Sounds like you are shooting a 338 Boomer. One wouldn't think it would drift much due to wind. However, I learned otherwise. Shooting to 500 meters I became quite confused.

    My solution was to "click" over until windage was spot on. The key is to remember which way and how many clicks you went.

    I then shot only when the mirage was indicating the wind was going the other direction. Then noted shot placement. That gave me a much better feel for the wind effect.

    I too tho't that the scope was mounted out of wack but nay, it was just the wind.

    In Utah GG measured the 225 AB BC @ 0.565. Down in MO it is most probably less, unless I'm thinkin' backwards again.

    I was shooting a bullet w/published BC of 0.465 and a nice semi steady 5 to 7 mph wind @ about 90% seemed to move it about 4 inches at ~542yds and proportionally less @ 300m & 400m.
     

  3. sambo3006

    sambo3006 Well-Known Member

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    I just looked on the eskimo.com link for ballistic table. For my bullet and a 10mph crosswind it lists 2.1" drift at 200 yds and 0.5" for 100 yds. I think I need to sight in for windage at 100 yds and trust the scope. I am going out to western Colorado on Oct 10 for the 1st season elk rifle hunt (Oct 14), and I want to make sure that the rifle is indeed zeroed for no wind. I know that my load matches the hashmarks for drop on the Ballistic Plex basically dead on out to 500 yds, so I don't have to worry about that. I just don't want to wound an elk because my bullet is hitting off to the side at 500 yds. If there is some wind I want to be able to put in some clicks and trust it.
     
  4. J E Custom

    J E Custom Well-Known Member

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    3006

    I would check for scope canting.

    Even a very small amount of canting can cause zero to
    change as distance is increased.

    Catch a no wind condition and zero at 100yrds

    then 200,300,400 and 500yrds,adjusting only the elevation, if the scope is canted the windage error will increse with distance.

    If no windage error occurs then you are good to go.

    J E CUSTOM