Conversion from mil-dot to MOA on IOR MP-8

Discussion in 'Long Range Scopes and Other Optics' started by Black Diamond 408, Mar 4, 2004.


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  1. 700

    700 Well-Known Member

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    For those US Americans and some Europeans who cannot visulise in Meters, the Mildot system is not unit specific.

    A miliradian also substends

    1 yard @ 1000 yards.
    1 foot @ 1000 feet.

    Ranging is similar:

    A 1.8 meter target measures 2 Milliradians when viewed through the scope.

    Range= (1.8/2) x 1000 Meters
    = 900 Meters

    A 2 yard target measures 4 Milliradians when viewed through the scope.

    Range= (2/4) x 1000 Yards
    = 500 Yards

    A 6 foot target measures 4 Milliradians when viewed through the scope.

    Range= (6/4) x 1000 Feet
    = 1500 Feet

    It is those MOA and Inch turret adjustments make a mess of these systems.

    Rgds

    700
     
  2. Jeff In TX

    Jeff In TX Well-Known Member

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    [​IMG] I think it's like most anything out there. Mil-dots/MP8 reticles are not hard to use once you understand the basics. if you practice with them, it becomes second nature. I think you'll find that with any range finding reticle system out there. To be good with any of them, it all comes down to practice.

    Mildots have stood the test of time, but like most anything, better systems are being developed.

    I try to keep an open mind on these things an most of them I understand. But the one that baffles the hell out of me the most is the TDS reticle. For my life, I can't figure that one out.

    Anyone like to explain that one?
     
  3. DMCI

    DMCI Well-Known Member

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    Gentlemen:

    I probably do this once a week, but there is a lot of fog in the air about Mil Dots, but hopefully this will help.

    Ranging tool:

    The WERM formula is as follows:

    Height of target (yards) x 1000
    -------------------------------- = Range(Yds)
    Height Target (Mils)


    So if your target is 72" and the Mils is 4, your range is 500 yards. (As Rush says, for those of you in RIO LINDA, 72" is exactly 2 yards!)

    or if your target is 36" and your mils is 3,
    your range is 333 yards.

    1 yard x 1000
    ------------- = 333 yards
    3 mils

    or if your target is 18" and your mils are 2, your range is 250 yards.

    Now a slight variation on this which generally requires a calculator is

    Height target (in)x 27.7
    ------------------------ = Range (yds)
    Mils observed

    or you can round off to 30 and do the calculation in your head.

    I have found however, that the formula for target height in yards is the easiest to use.

    That 3.3... jazz just confuses the issue.

    (Note: If you are a Prairie Dog shooter, and your target is 9" tall, and you see 2.5 mils, your range is .25x1000/2.5=100 yards! [​IMG])

    D. [​IMG]

    PS: Now that you know the range you need to adjust your knobs for the hold over. You just make you come up chart in MOA and dial that in with your knob.

    Alternatively, you can make the come up chart in Mils and uses the dots for holdover, but that is a little more difficult. By the way, this is why you need a scope with accurate mil dots and/or accurate clicks.

    A come up chart might look something like this:

    Code:
    
    
    I can't help it, thats the way it is! [​IMG]

    [ 03-30-2004: Message edited by: DMCI ]
     
  4. Dave King

    Dave King Well-Known Member

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    DMCI

    Thank you!!

    For years I've had an MOA come-up chart in the scope cover of my rifle(s) but it never occured to me to add the Mil come-up value to the data for the MilDot scopes... I'll be doing that little addition directly. Just amazing the little things we can't see until someone holds our head in the correct direction!! Thanks again.

    [ 03-30-2004: Message edited by: Dave King ]
     
  5. sscoyote

    sscoyote Well-Known Member

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    You know guys, i've been hanging around here for a year or so, and for the life of me, i don't understand why you would need to put comeups in a MOA measurement when the turret is calibrated. If you know the exact comeup for each range why not just calculate the exact calibration # on the turret and just put that on the range card/sticker. What is the advantage of using MOA #'s when i think (sometimes that part gets me in trouble, by the way-- probably here too)that with a MOA chart you would have to do yet another calculation in the field. Please enlighten me.

    DMCI-- just wanna' be sure i gots this stuff here. That range sticker is a holdover system in mils, and a comeup system in MOA-- right?? This may seem like a dumb ? but... that's my way sometimes.

    [ 03-30-2004: Message edited by: sscoyote ]

    [ 03-30-2004: Message edited by: sscoyote ]
     
  6. DMCI

    DMCI Well-Known Member

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    <BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR> DMCI-- just wanna' be sure i gots this stuff here. That range sticker is a holdover system in mils, and a comeup system in MOA-- right?? This may seem like a dumb ? but... that's my way sometimes. <HR></BLOCKQUOTE>

    Sort of two sides of the same coin:

    For MOA, once we have the range, we need to come up on the elevation knob so much in MOAs.

    For Mils, we don't come up with the knob (although obviously you could.), we hold over the normal point of aim so many mils.

    Just a word usage or nomenclature issue.

    D. [​IMG]
     
  7. Dimitrios

    Dimitrios Well-Known Member

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    <BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR> For Mils, we don't come up with the knob <HR></BLOCKQUOTE>
    unlles you have a metric scope
     
  8. DMCI

    DMCI Well-Known Member

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    <BLOCKQUOTE><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><HR> quote:
    --------------------------------------------------------------------------------
    For Mils, we don't come up with the knob
    --------------------------------------------------------------------------------


    unlles you have a metric scope <HR></BLOCKQUOTE>


    Metric scopes are actually pretty cool. I would still bring the scope up and use the dots for aiming point, but you could dial in the decimal part of the comup.

    So for example if the come up was 4.6 Mils, I would use the fourth dot as my aiming point and dial in the .6 mils with my knob.

    Problem is, you are limited in the number of dots available. But there is hope by using the Horus reticle.(Shown here below.)

    [​IMG]
     
  9. sscoyote

    sscoyote Well-Known Member

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    I know a lot of guys don't like the reticle because it's so complicated, or maybe "cluttered" is a better word. But it certainly looks "exacting" to me. I mean a fine grid like this should provide for a very precise reference, correct??
     
  10. DMCI

    DMCI Well-Known Member

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    That Horus reticle has a number of benefits, other than working with their software. Now the PDA software in conjunction with the Weather meter will give you a recommendation for a hold over in a 10 mph wind at a range of 923 yards (Data from LRF) of say 9.3 of elevation and 3.2 mils of windage, you just put that point on the matrix on the target and squeeze the trigger. A miss provides information about point of impact and prepares for the second shot, to wit:

    If you can see the point of impact on the reticle, then you put that point on the matrix on the target and you are virtually guaranteed a second round hit. This is true of any reticle, but the benefits here accrue from the ability to precisely pin point the location of the hit.

    D. [​IMG]

    PS. A lot of what happens with this reticle, of course assumes shooting from some kind of rest for stability. Oh, and the knobs on the Horus scopes are calibrated in Mils, which should make our METRIC friends giddy! [​IMG]

    I also note that the cross and the larger dots below it are reflective material which are lit at night by the lit reticle mechanisms.

    The reticle grows and shrinks because it is front focal plane. As you reduce the power more lines are shown, down to line 27 if I remember correctly. This alows for pot shots at extremely long range, which after all is what we are about here, isn't it! [​IMG] (27 mils of come up will get you well in excess of 1000 yards for most rounds.)

    [ 03-31-2004: Message edited by: DMCI ]
     
  11. Dimitrios

    Dimitrios Well-Known Member

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    SSC earlier models had much thicker lines and it was more cluttered ...looks like Horus vision is refining their reticles they are on the 3rd gen reticles now..still allot of shouters don't like them while others swear by them..i would like to put my eye behind one.I have the spotter with the horus reticle and i think its pretty good i like it
    it can work with any mil dot equipped scope really good...
     
  12. sscoyote

    sscoyote Well-Known Member

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    You know i called Dennis Sammutt about that system several years back, and was gonna purchase one but never got around to it-- soon i hope. I know the reticle is etched on in the 1st focal plane. So you think it's the cat's meow (or should i say the prairie dog's bark) DMCI?? I've also heard the software is lacking, but sound like your experience with it is good, ehhh?