Dead on at 400, gun shoots left at 100?

Discussion in 'Long Range Hunting & Shooting' started by WEATHERBY460, Nov 20, 2012.

  1. WEATHERBY460

    WEATHERBY460 Well-Known Member

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    I am shooting 1" to the left at 100 yards, but I am dead on at 400 yards....what is my problem? I do have a scope level on my scope, that is leveled with the scope base. Thanks for any help.

    gun is savage 338 lapus fcp, nightforce 22x
     
  2. jmden

    jmden Well-Known Member

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    Spin drift may be the answer. If you have a right twist barrel, as most are, the bullet will drift to the right a bit over it's flight. Some guys deal with it by zeroing a bit to the left at close range, as you are. Might just leave it alone at this point, unless you are planning on taking some much longer shots.
     

  3. JackinSD

    JackinSD Well-Known Member

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    Probably no problem at all. If your rifle has a right hand twist it could easily be moving that far right at 400 yards. My .243 moves .8" at that distance.
     
  4. 1SevenZero

    1SevenZero Well-Known Member

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    Be sure to check/ adjust your parallax.

    Be sure to verify your scope is actually level with the action.

    I'm sure you know this one, but scope levels can be mounted out of level.
     
  5. shortpants

    shortpants Well-Known Member

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    I would think SD would only move you .25-.5moa at that distance. I would double check to make sure your cross hairs are indeed level. Was this a one time thing or have you tested this on different days. If this was a one time thing I would do it again. Wind can play games with you.
     
  6. WEATHERBY460

    WEATHERBY460 Well-Known Member

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    if my crosshair is wrong, which way do i turn the scope when looking thru it...also

    what is the best way to check the scope level...shoot at yards, then adjust the scope to the 400 yard mark and shoot it again at 100?
     
  7. RTK

    RTK Well-Known Member

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    Draw a long vertical and horizontal line on a piece of butcher paper with a level "after you have taped it up", shoot a 100 yard group then dial up 30MOA and shoot again. That will tell you if your scope is level or not, keep your reticle perfectly on the horizontal and vertical lines for both groups
     
    Last edited: Nov 20, 2012
  8. shortpants

    shortpants Well-Known Member

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    If you need to move it you'll move it in the direction of your impact so in your case that would be counter clockwise.

    Put a plumbline out in front of your rifle 10-15ft so you can see it when your looking through your scope. Focus the scope. Level your rifle. You can open your mag box and strap an ordinary level under the magazine well. Put a small level on top of your turret. Look through the scope and see if the cross hairs line up perfectly with your plumbline. Make sure the action stays level. Adjust the scope until the turret level matches the action level. This is just a rough method you can do at home. There is a better way at the range where you shoot at a plumbline but I'll have to explain that in a bit, I'm at work right now.
     
  9. shortpants

    shortpants Well-Known Member

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    This is what I was going to tell you. You want to draw an upside down T. Make sure the vertical line is perfectly plumb. Zero you rifle where the lines intersect. Then dial up 30moa and shoot another group. If it is hitting left twist the scope that direction, if right twist right. Do this test at 100yds and make sure your crosshairs are lined up with the lines on the target.
     
  10. WEATHERBY460

    WEATHERBY460 Well-Known Member

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    Makes sense...thanks!!!!!!!!!!!!!!
     
  11. backwoods83

    backwoods83 Well-Known Member

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    I think its everything that's been mentioned, your crosshair is slightly canted clockwise and needs straightened, also if your shooting 250grn and lighter bullets from a 9 twist savage barrel you have close to a 3:1 stability factor which will give you around 2.5moa spin drift at 1k yrds not sure at 400 but probably 1/2-5/8moa.
     
  12. RMulhern

    RMulhern Well-Known Member

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    Well...get it dead on at 100 and then you can shoot right at 400!!
     
  13. Bravo 4

    Bravo 4 Well-Known Member

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    Wow! That just seems like a huge amount of spin drift.
     
  14. backwoods83

    backwoods83 Well-Known Member

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    Shooter says 1moa drift at sea level with 250grn smk's at 1k.