I NEED SOME CHAIR GUN HELP

Forums Optics, Scopes, Rings, & Mounts I NEED SOME CHAIR GUN HELP

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    2D1C
    Participant
    Member

    I have following info plugged in.

    MV 909

    JSB KH34 gn.

    BC.036

    scope 2.50

    KZ .75

    It says -3.59 for 100 yards on the range card. But 100 yards actual is 3.1. All the setting are high. I checked my velocity on 2 different Chronies, and I checked my range finder at the club with known yardage targets. What am I missing here?

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    AnimalHitman
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    You may not have the Ind. Mag and Cal. Mag entered correctly. If you have a variable power scope, enter the max magnification in the Cal. Mag field and your magnification setting in the Ind. mag field. Hope this helps 🙂

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    frank320
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    From my experience, JSB King Heavies 34gr's BC at that speed would be around 0.05 or better.

    A much better BC towards the 100 yd mark could help explain the higher settings.

     

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    2D1C
    Participant
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    I'll play with those suggestions.

    Thank you

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    2D1C
    Participant
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    Both your guys suggestions appear to have me back on track. I will know this weekend. I found a spot where I can stretch the barrel out beyond 150 yards.150 is my max without adjusting the rings right now. I am hoping to use the turret and the holdover to get past there.

    Thank you again for the assistance!

     

    Dennis

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    Centercut
    Participant
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    Yes, I think you have your BC set too low. Assuming other inputs are correct, I'd move the BC up until you get the correct holdover mil dots. I wouldn't jump right to .05 or more, since for various barrels the BC will vary, and also various pellet speeds. Could be anywhere from .042 to .056. Depends on pellet speed and barrel, like LW, LW Poly, ST, or STX… 

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    2D1C
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    It works out if the BC is.060. I'll let you guys know.

    Thanks!!

    Dennis

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    ShootistX
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    2D1C

    It works out if the BC is.060. I'll let you guys know.

    Thanks!!

    Dennis

    Your BC is probably not .060.

    The problem is more than likely scope height. Most people get that wrong. The get your scope height,,,,,,get yourself a target. Place the target 1 foot or less from the muzzle.

    Now get a piece of aluminum foil and cover the objective of your scope . Now punch a hole in the center of the foil with a ink pen. Now look through your scope, find the center of the target and fire a shot at point blank range. Measure the center of the target to the hole your pellet made and there you have the very nearly exact scope height.

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    2D1C
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    Interesting! I did play with the scope height it made a little difference but not much. I agree that the BC is probably not .060 however that setting gets me back on target.

    I went to a spot that I can shoot out past 150 yards to point blank and the clicks per the shoot card are good. I'll go to the range this weekend and see exactly where the POI is at known yardage.

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    cmatera
    Participant
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    For the easy way to find scope height, take calipers and measure the OD of the barrel under the front objective end of the scope and divide by 2.  Write that number down.  Take your calipers and measure the space from the tpp of the barrel to the bottom of the scope objective.  DO NOT DIVIDE BY 2.  Write that number down.  Take your calipers and measure the OD of the front objective of the scope.  Divide it by 2 and write that number down.  Add the 3 numbers you wrote down, and that is your scope height.  No shooting or target setup necessary.

    • This reply was modified 1 week ago by cmatera.
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    Centercut
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    @cmatera, exactly how I do it. Easy, fast and accurate…

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    cmatera
    Participant
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    And really nice in winter if you live where there's lot's of snow and cold.  You can do it all inside your nice warm house.

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    2D1C
    Participant
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    Sweet……. Thank you all I have a plan!

    Dennis

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