Mil Dot Chart

Discussion in 'Long Range Scopes and Other Optics' started by Da Grizz, Dec 19, 2003.

  1. Da Grizz

    Da Grizz Member

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    I have a springfield 6-20 scope on a 22-250, 50 grn Nosler BT at 3647. Question is if it shoots dead on a 100 yds. First mildot at 100 shoots 4 in high. Would it be safe to say it will shoot dead on at about 340 yds. What would next mil dot shoot at and so on.
    [​IMG]
     
  2. Dave King

    Dave King Well-Known Member

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    Calibrated MilDots are 3.6 inches apart at 100 yards (3.44 MOA)

    If your 22-250 shoots dead-on at 100 yards at the crosshair and 4 inches high on the first MilDot there is a measurement problem I believe.

    You can run a ballistic chart for 3.44 MOA intervals and get the "distance" zero from that... best to actually shoot and see where they hit.


    You don't state environmentals so I used "standard" and a scope height of 1.75"

    50 Nosler .238 BC

    Zero plus 3.6 high (first MilDot) = 3.6 high at 100 yards and .5 low at 350 yards

    Zero plus 7.2 high (second MilDot) = 7.2 high at 100 yards and .3 inches low at 475 yards

    Zero plus 10.6 high (third MilDot) = 10.8 high at 100 yards and 1.3 inches low at 575 yards.

    You can run the numbers using the JBM ballistic website same as me for the rest.
     

  3. Nate Haler

    Nate Haler Well-Known Member

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    sounds like what Dave is saying is that your scope will pretty much be dead on at 340y using the first mildot below the crosshair intersection. [​IMG]

    Keep in mind that adjustting the scope magnfication might change the relative mildot spacing, unless the reticle changes size w/the magnfication.

    Try putting two heavy pointed lines (felt marker type) precisely 3.6" apart on a target at 100y. Peek thru your scope and two adjacent mildots should be centered on the marks at 'standard' mildot spacing. Crank the magnfication until everything lines up, and there you go. Let's say this is at 20x on your scope. You could then fairly safely assume that dialing down to 10x would result in the mildots equating to 7.2" spacing (between adjacent dots).

    [ 12-22-2003: Message edited by: Nate Haler ]
     
  4. 700

    700 Well-Known Member

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    Da Grizz

    I just emailed you some drop charts (inches and milliradians)and a drop table.

    I assumed standard athmospheric conditions and scope height of 1.7 inches and 100 yard zero.

    With those assumptions, 1 milliradian holdover will put your bullet on the mark at 340 yards.

    Regards

    700
     
  5. Brent

    Brent Well-Known Member

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    Da Grizz and Nate,

    The SA scope line has the reticle in the 1st focal plane, so mildots spacing from center to center will remain 3.6" (3.44 MOA) at any power setting.

    You might have a look at the Exbal ballistic program. It has a ballistic reticle analysis section, and once you enter your load, reticles vertical tic spacing (mildots, Custom BDC, NP-R2, etc) and "point blank target height" (+ or -2", 3", 4", etc, from POA, it will tell you the near and far zero range for each tic on the scope, and its actual zero range. Very cool program.

    The new PALM version of Exbal now has a range estimation calculator for use with the R2 or Mildot (right on!), and it's own maximum point blank range calculator too. The MPBR calculator tells you how high or low the shot will be if using a specific tic mark for the range you enter, works slightly different than the desktop Exbal program, it is very usefull.

    Ric,
    You should get the new updated Exbal programs too, well worth the $13 to update. You'll love the new layout, links and features. I had mine two days after ordering it over the web, and thanks to John M. for pointing out they were available!!! Gerald's site didn't show the new screen views for the programs, just the older version. http://www.perry-systems.com

    The new PDA software is a real nice improvement, also includes an actual drop chart link on the firing solution window... way cool.
     
  6. Hunter

    Hunter Well-Known Member

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    I just upgraded Exbal for my Palm Tungsten T3. Version 4.2 is out now. It has several new features, like bullet lookup screens. Upgrade is now $17.50, but still a bargain. I think the program is just plain awesome.
     
  7. Michael Eichele

    Michael Eichele Well-Known Member

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    My program lets you do this:
    [​IMG]

    It also lets you do it in NF NP-R2 and a few more popular ones. Just enter in your drops and zero, the diagram does the rest.
     
  8. nottoofar

    nottoofar Active Member

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    Dagrizz,
    Looks like you already have received lot of great info.
    Just though I would add that there is a handy mildot rangefinding chart at the Pentax web site.

    Gives you different info per the size of the animal you are shooting at for using the mildots as a range finder.
     
  9. Brown Dog

    Brown Dog Writers Guild

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    Da Grizz,

    Just tried to post an Excel table I produced for my 300 -but failed.
    Basically, I wanted to know what my mil-dots were giving me if I had already set an elevation on the turret (so that if -for whatever reason- I need to take rapid follow-up shot on a target that's moved to a new range, I could do so with some accuracy without having to reset the turret.)
    I find with mils it's much easier to use metres and cm.
    Here are some examples for my 300:
    Elevation turret set to 100m; 1st mil dot is on at 275m
    Elevation turret set to 200m; 1st mil dot is on at 325m
    Elevation turret set to 300m; 1st mil dot is on at 405m

    and so on. The actual table gives mil values at 25m increments; eg Elevation turret set to 225m; target moves to 425m, aim off 1.8 mils.

    It was pretty easy to produce in Excel.

    For your round, using the same assumed data as Dave, I get(remember this is metres):

    Elevation set to 100m:

    New Range Aim off in Mils
    150---------------0.1
    175---------------0.2
    200---------------0.3
    225---------------0.4
    250---------------0.6
    275---------------0.8
    300---------------0.9
    325---------------1.1
    350---------------1.3
    375---------------1.5
    400---------------1.7
    425---------------2.0
    450---------------2.3

    [ 02-25-2004: Message edited by: Brown Dog ]

    [ 02-25-2004: Message edited by: Brown Dog ]

    [ 02-25-2004: Message edited by: Brown Dog ]
     
  10. tgipe01

    tgipe01 New Member

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    You need to find a balistics calculator for the bullet caliber, weight and Bc and use the chart.
     
  11. Bravo 4

    Bravo 4 Well-Known Member

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    I agree, but those things weren't as popular in 2003 as they are now.:D