200yd shooting in 100yd hole?

Discussion in 'Rifles, Bullets, Barrels & Ballistics' started by ohiohunter, Oct 26, 2013.

  1. ohiohunter

    ohiohunter Well-Known Member

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    Ok, new to most of this but very puzzled by this. Shooting 280rem, 168 hybrid berger, 56.5g 4831sc, 24" barrel, calculated ~2825fps

    I was being conservative w/ my shot count due to deer season around the corner. My 200yd shots coincide w/ my 100yd shots. The one target shows some drop but not anywhere near what the charts say it should be. Why or how am I shooting so flat? The wind deflection seems relatively consistent w/ perceived wind and chart readings.
     

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  2. ohiohunter

    ohiohunter Well-Known Member

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    lets try this
     

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  3. Greyfox

    Greyfox Well-Known Member

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    Some questions.

    How high above the bore line is your scope mounted? The higher, the flatter at 200 yards for POI.

    Have you done a box test with your scope, or a 100 yard check for POI change/tall target test of turret adjustmentor BDC crosshair at 100 yards and confirm?

    Scope parallax adjusted properly?

    Did you use the exact same rest at 100 and 200 yards?

    Is your visual focus when shooting on the "crosshair only" for both ranges?

    What was the bore's condition at the start of the test, clean, fouled, how many shots?

    Is your barrel free floated? Cooled between shots.

    When I have experienced this effect over the years, it has usually been one or more of the above. IMO
     
  4. jfseaman

    jfseaman Well-Known Member

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    Don't fight it. Go hunting and be confident.

    Really.

    But yes it's a scope height issue but obviously not a bad one.
     
  5. ohiohunter

    ohiohunter Well-Known Member

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    Scope is a 42mm on low mounts. It's about as close to the barrel as you can get. It's a light varmint barrel so a 5shot string shouldn't effect much. The 4shot one hole was shot one 2dif days. 100 then 200.

    I then tried to see if I could duplicate my results. I basically did considering the wind and mirage.
     
  6. ohiohunter

    ohiohunter Well-Known Member

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    Free floated
    Fouled bore
    Same rest
    Parallax adjusted

    When I shot lighter loads it followed suit, but the hotter load shot dramatically flatter.
     
  7. Birdhunter1

    Birdhunter1 Well-Known Member

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    What do you have the rifle zeroed at? It is possible the trajectory is on the rise at 100 yards and on the fall at 200 yards and they happen to be at the same height above line of sight.
    For instance on my .22 rifle I zero it at 25 yards and it will also be zeroed at 75 yards and about 3/4" high at 50 yards.
     
  8. ohiohunter

    ohiohunter Well-Known Member

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    I think the zero is irrelevant here.

    I thought of the rise/fall also, and so far that is the only logical explanation. In relation would be how low my scope is being as I'm shooting a med/small objective and its sitting about 1/8" off the barrel. Where as if my scope were higher the two 0's would have a greater distance between them. B/c I did get a little drop on the one target (and ~1/4" on the other) I guess the apex of my bullet occurs between 100 and 200yds.

    After my deer hunt I'll have to play around w/ it some more and get longer range info.
     
    Last edited: Oct 26, 2013
  9. Birdhunter1

    Birdhunter1 Well-Known Member

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    That is what I was referring to, I ran into an issue on my .243 a few years ago when playing with different zero ranges and was at first dumfounded when my rifle (with a scope set up low like yours) that I was roughly the same point of impact above point of aim at 100 yards and 225 yards. I think that zero was for 250 yards and the apex of the trajectory was around 160 something yards.
     
  10. westcliffe01

    westcliffe01 Well-Known Member

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    Using the G7 ballistic calculator on this site and your quoted data, drop from 100-200 is about 1.5". That seems to be exactly what the second target is showing.
     
  11. skandlus

    skandlus Well-Known Member

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    Just wondering... Have u shot it at 200 yds after the 100 yd groups?

    Another sugg, Maybe your set screw on the turret got loose??? Happened to a buddy of mine last week
     
  12. LONGSHOOTER

    LONGSHOOTER Well-Known Member

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    Ah, but your zero IS relevant. Probably about 230-240 yard zero.
     
  13. ohiohunter

    ohiohunter Well-Known Member

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    Well color me stupid. I thought that regardless of zero you'd still have the same bullet drop from x to y. Then considering the topic some more I put it against my ballistic calc. And sure enough that is exactly what it is.

    I was attempting to set a mpb range out to 300 which I think I am very close to, maybe off by an inch or so.

    Thanks for pointing that out.
     
  14. SidecarFlip

    SidecarFlip Well-Known Member

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    In as much as the kill zone on an average Ohio (or Michigan) buck is 12-14", I'd say 'go hunting' as well. Paper is one thing, animals are another.

    Everyone of your hits were/are a killing hit. Certainly nothing to be concerned about...