Mildot ranging for Whitetails,

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  • Mildot ranging for Whitetails,

    I worked out a table for ranging and wondered if someone could check my math? I had a bad head injury (Any good injuries?) so my skills are questionable to me now.

    using a 36" target (average ground to back for Whitetails) and converting to yards using the formula: h"x27.77 /mils=yards

    5.5mils =181.77
    5 mils = 199.94
    4.5 mils =222.16
    4 mils =249.93
    3.5 mils =285.63
    3 mils =333.24
    2.5 mils =399.89
    2 mils =499.86
    1.5 mils =666.48
    1 mil =999.72
    .5 mils =1999.44
    .2 mils =5000


    I kinda spaced until I remembered the whole angular geometry thing (Its been a while) but I think it works. If there is a table already done I'd appreciate it. Also if anyone has any drops in a table done for factory 123 SST's in 18" barrel I'd appreciate it also. now I need to strain my noodle and remember the Mil/MOA conversion formula, maybe I'll just look it up for my clicks.
    Last edited by Guest; 09-18-2013, 03:18 PM.
  • LR1955
    Super Moderator
    • Mar 2011
    • 3355

    #2
    Joker:

    I moved the thread so it isn't your head injury.

    Your math is fine. Now, round the numbers and put to memory the distances for 3 and 2 mils (300 and 500). Easy enough. I doubt you will be shooting animals at 5000 meters without your M-1 Tank.

    Doctrinally, a mil is 3.375 minutes. I round it up to 3.5 minutes for speed.

    Almost all modern small arms ammunition has basically the same trajectory to 300 yards and almost the same to 500 yards.

    Although I don't know the velocity of your 123 SST load, my bet is that your come ups will look very close to the following.

    100 - 200 = 1 1/2 minutes

    200 - 300 = 2 1/2 minutes

    300 - 400 = 3 1/2 minutes

    400 - 500 = 4 minutes

    So, you can convert minutes to mils by dividing the come ups by 3.375. For example, your come up between 300 and 400 would be one mil.

    I imagine you want to use the mil reticle for holds. Figure out your zeroing elevation first. My advice is to zero at the nearest 100 yards to the distance you expect to get a shot. Then make your table.

    Keep your table simple -- no more than three holds and keep your holds at increments of no less than 1/4 mil.

    36 inches is a pretty big kill zone. There are a couple of different ways of approaching it but you need to figure out what you can remember and implement when excited.

    No animal will be 36 inches, it is almost impossible to mil anything that is moving or when your rife is moving. Depending on the reticle pattern, you might be able to discern increments under 1/4 mil but trying to remember what they are is difficult. If you take your eyes off the target to refer to a cheat sheet, chances are you will find you can't read the cheat sheet because it is either to dark out, the writing is too small, or the writing has been destroyed by the elements. And when you raise your eyes to find your game again, it has moved. Memorize one or two holds based on your expected engagement ranges and use them.

    The more a guy tries to wargame these things, the greater becomes the potential that he will make a big mistake somewhere along the way.

    LR1955

    Comment

    • BjornF16
      Chieftain
      • Jun 2011
      • 1825

      #3
      LR1955

      Joker is using ground to top of back (height) for his 36". Would it be better to use "brisket" or chest cavity height for ranging?
      LIFE member: NRA, TSRA, SAF, GOA
      Defend the Constitution and our 2A Rights!

      Comment

      • Drifter
        Chieftain
        • Mar 2011
        • 1662

        #4
        Originally posted by BjornF16 View Post
        LR1955

        Joker is using ground to top of back (height) for his 36". Would it be better to use "brisket" or chest cavity height for ranging?
        I use the brisket since it seems easier to get a quick and complete view.

        I agree with LR1955 in memorizing a few key numbers. For my application (and I don't recall the measurements I'd taken over time, nor the formula, but generally speaking...), a mature whitetail buck that measures 1-mil is roughly 400 yards away and requires a 2-mil adjustment for my zero and load. The visible part of a coyote in the field is often similar in size, so the same generalization works. If the animal measures larger, meaning it's closer than 400 yards, appropriate adjustment isn't too complicated. If the animal measures smaller, meaning more than 400 yards, it's probably a good idea to reevaluate the shot, use a laser rangefinder, reconsider the wind, etc. At extended distances, a slight misjudgment has greater consequences on the shot.
        Last edited by Drifter; 09-19-2013, 01:09 AM.
        Drifter

        Comment

        • mongoosesnipe
          Chieftain
          • May 2012
          • 1142

          #5
          Originally posted by LR1955 View Post
          Joker:

          I moved the thread so it isn't your head injury.

          Your math is fine. Now, round the numbers and put to memory the distances for 3 and 2 mils (300 and 500). Easy enough. I doubt you will be shooting animals at 5000 meters without your M-1 Tank.

          Doctrinally, a mil is 3.375 minutes. I round it up to 3.5 minutes for speed.

          Almost all modern small arms ammunition has basically the same trajectory to 300 yards and almost the same to 500 yards.

          Although I don't know the velocity of your 123 SST load, my bet is that your come ups will look very close to the following.

          100 - 200 = 1 1/2 minutes

          200 - 300 = 2 1/2 minutes

          300 - 400 = 3 1/2 minutes

          400 - 500 = 4 minutes

          So, you can convert minutes to mils by dividing the come ups by 3.375. For example, your come up between 300 and 400 would be one mil.

          I imagine you want to use the mil reticle for holds. Figure out your zeroing elevation first. My advice is to zero at the nearest 100 yards to the distance you expect to get a shot. Then make your table.

          Keep your table simple -- no more than three holds and keep your holds at increments of no less than 1/4 mil.

          36 inches is a pretty big kill zone. There are a couple of different ways of approaching it but you need to figure out what you can remember and implement when excited.

          No animal will be 36 inches, it is almost impossible to mil anything that is moving or when your rife is moving. Depending on the reticle pattern, you might be able to discern increments under 1/4 mil but trying to remember what they are is difficult. If you take your eyes off the target to refer to a cheat sheet, chances are you will find you can't read the cheat sheet because it is either to dark out, the writing is too small, or the writing has been destroyed by the elements. And when you raise your eyes to find your game again, it has moved. Memorize one or two holds based on your expected engagement ranges and use them.

          The more a guy tries to wargame these things, the greater becomes the potential that he will make a big mistake somewhere along the way.

          LR1955
          Punctuation is for the weak....

          Comment

          • LR1955
            Super Moderator
            • Mar 2011
            • 3355

            #6
            Originally posted by mongoosesnipe View Post
            i think you may have mixed up minutes and mils in your drop estimate

            123 sst calculated at 2400fps

            Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
            (yd) (MOA) (mil) (MOA) (mil) (ft/s) (none) (ft•lbs) (s) (MOA) (mil)
            0 *** *** *** *** 2405.6 2.155 1580.3 0.000 *** ***
            100 -0.0 -0.0 0.8 0.2 2239.6 2.006 1369.7 0.129 21.7 6.3
            200 -2.6 -0.8 1.6 0.5 2080.0 1.863 1181.4 0.268 22.5 6.6
            300 -6.0 -1.8 2.5 0.7 1927.3 1.726 1014.3 0.418 23.4 6.8
            400 -10.0 -2.9 3.4 1.0 1781.8 1.596 867.0 0.580 24.4 7.1
            500 -14.4 -4.2 4.4 1.3 1644.5 1.473 738.5 0.755 25.4 7.4
            600 -19.5 -5.7 5.5 1.6 1516.4 1.358 627.9 0.945 26.5 7.7
            700 -25.1 -7.3 6.7 1.9 1398.8 1.253 534.3 1.151 27.6 8.0
            800 -31.5 -9.2 7.9 2.3 1293.5 1.159 456.9 1.375 28.9 8.4
            900 -38.7 -11.2 9.2 2.7 1202.2 1.077 394.6 1.615 30.2 8.8
            1000 -46.7 -13.6 10.5 3.1 1126.5 1.009 346.5 1.874 31.5 9.2


            also i would range whitetail from biscuit to back because if it is standing in the grass you will be guessing at the ground height similarly with humans it is best to mil from crotch to head as one meter as most height variation is in the legs

            also the calculation is easier if you measure target in yards..
            (height in yards/mil)*1000= distance in yards and since your multiplying by 1000 you can just move the decimal 3 places which is easier to do in your head compaird to multiplying by 27.78
            so assuming a 18 inch chest on a deer which is 0.5 yards
            (.5 yards hieght/ 5mils)=.1 *1000= 100 yards
            (.5 yards/4mils)=.125*1000= 125 yards ...

            using deer chest
            5 mils=100 yards
            4 mils=125
            3 mils=166
            2.5 mils=200
            2 mils=250
            1.5 mils=333
            1 mill=500

            honestly past 300 you are getting to the point where exact yardage is becoming more and more important if you want to shoot at deer past that i would recommend a rangefinder and a nice scope with zero lock and good repeatable turrets
            MGS:

            Nope. I didn't confuse mils with minutes and my table is giving come ups (elevation changes) like yours does. In fact, the two are almost identical.

            Your table shows a come up between 100 and 200 as 1.6 Minutes. Mine is 1.5 minutes. Yours shows a come up between 200 and 300 as being 2 1/2 minutes. Mine is 2 1/2 minutes. Yours from 300 to 400 as 3.4 minutes and mine as 3.5. Yours from 400 - 500 as 4 1/2 and mine as 4 minutes.

            Mine is based on a BC of about .5 at about 2550 which is a decent mean when a guy is using a relatively well designed bullet at a relatively slow speed. As I said before, all decent small arms have close to the same trajectory to 300 and once you get to 500 you start seeing some differences. Past 500 and you see much bigger differences.

            I would not use a cheat sheet in this situation. It isn't necessary. And, the table that MGS produced showed how easy it is to mistake things like come ups with bullet drop, minutes with mils, etc.

            Memorize one or two key pieces of information and practice them on a range to make sure they are workable when you are under stress. You would be amazed at how complex some brilliant ideas are when a guy tries to implement them! I will always test a 'brilliant idea' first. And by doing so, I normally find out it wasn't so brilliant after all.

            LR1955
            Last edited by LR1955; 09-19-2013, 12:10 PM.

            Comment

            • LR1955
              Super Moderator
              • Mar 2011
              • 3355

              #7
              Originally posted by BjornF16 View Post
              LR1955

              Joker is using ground to top of back (height) for his 36". Would it be better to use "brisket" or chest cavity height for ranging?
              Bjorn:

              Use what ever is most comfortable for the shooter.

              I wouldn't use the ground for too much as grass and things obscure where the ground really is. If there is very high grass, it would be impossible to figure out where the ground was.

              I probably wouldn't mil something unless I was sure the range was past 300 yards, anyway.

              LR1955

              Comment

              • mongoosesnipe
                Chieftain
                • May 2012
                • 1142

                #8
                Originally posted by LR1955 View Post
                MGS:

                Nope. I didn't confuse mils with minutes and my table is giving come ups (elevation changes) like yours does. In fact, the two are almost identical.

                Your table shows a come up between 100 and 200 as 1.6 Minutes. Mine is 1.5 minutes. Yours shows a come up between 200 and 300 as being 2 1/2 minutes. Mine is 2 1/2 minutes. Yours from 300 to 400 as 3.4 minutes and mine as 3.5. Yours from 400 - 500 as 4 1/2 and mine as 4 minutes.

                Mine is based on a BC of about .5 at about 2550 which is a decent mean when a guy is using a relatively well designed bullet at a relatively slow speed. As I said before, all decent small arms have close to the same trajectory to 300 and once you get to 500 you start seeing some differences. Past 500 and you see much bigger differences.

                I would not use a cheat sheet in this situation. It isn't necessary. And, the table that MGS produced showed how easy it is to mistake things like come ups with bullet drop, minutes with mils, etc.

                Memorize one or two key pieces of information and practice them on a range to make sure they are workable when you are under stress. You would be amazed at how complex some brilliant ideas are when a guy tries to implement them! I will always test a 'brilliant idea' first. And by doing so, I normally find out it wasn't so brilliant after all.

                LR1955
                gotcha drop vs come ups but the column wher our numbers match is actually windage the copy and pasted chart gets a little confusing i estimated the velocity based on hornady factory stated velocity from a 16 inch barrel as he is using an 18 inch barrel
                Punctuation is for the weak....

                Comment

                • LR1955
                  Super Moderator
                  • Mar 2011
                  • 3355

                  #9
                  Originally posted by mongoosesnipe View Post
                  gotcha drop vs come ups but the column wher our numbers match is actually windage the copy and pasted chart gets a little confusing i estimated the velocity based on hornady factory stated velocity from a 16 inch barrel as he is using an 18 inch barrel
                  MGS:

                  Hard to believe it but it is true! Very strange indeed that your wind and my elevation would be almost the same! This chart is much easier to read than the first.

                  Your chart also gives come ups but is cumulative from a 100 yard zero and presented as drop for some reason. Never saw a chart that presented drop in minutes but it is easy enough to understand.

                  I would shoot that load before believing that specific chart. I have shot my fill of flat base bullets and bullets with lousy BC's but none of them needed that much elevation for any of those distances.

                  LR1955

                  Comment

                  • Klem
                    Chieftain
                    • Aug 2013
                    • 3507

                    #10
                    Scope manufacturers who market Metric reticles with Imperial turrets need to be rounded-up. This normative pressure to stick to an antiquated measuring system is the bain of US shooters. The mental conversion needed between metric and Imperial when under stress is one less hassle you need, and can be eliminated so easily.

                    Metric reticles go with metric knobs. Imperial reticles (Nightforce do a Mildot equivalent reticle in MOA) go with Imperial knobs. Common sense I know but there are more US scope manufacturers offering Metric/Imperial than there are Metric/Metric or Imperial/Imperial and this thread wouldn't exist if Manufacturers paid more attention to how their products are used in the field.

                    My two cents for what it is worth, if you want to use a metric reticle get a scope with metric adjusters. Front focal plane allows you to use the reticle at any magnification (another hassle you don't have to worry about under pressure) however this comes at the expense of a reticle that expands as you dial up.

                    Comment

                    • mongoosesnipe
                      Chieftain
                      • May 2012
                      • 1142

                      #11
                      calculated with jbm ballistics http://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi you can set it to calculate drop and wind in: inch,inch/100y, cm, cm/100m,mil,moa
                      Punctuation is for the weak....

                      Comment

                      • Drifter
                        Chieftain
                        • Mar 2011
                        • 1662

                        #12
                        Originally posted by Klem View Post
                        Scope manufacturers who market Metric reticles with Imperial turrets need to be rounded-up. This normative pressure to stick to an antiquated measuring system is the bain of US shooters. The mental conversion needed between metric and Imperial when under stress is one less hassle you need, and can be eliminated so easily.

                        Metric reticles go with metric knobs. Imperial reticles (Nightforce do a Mildot equivalent reticle in MOA) go with Imperial knobs. Common sense I know but there are more US scope manufacturers offering Metric/Imperial than there are Metric/Metric or Imperial/Imperial and this thread wouldn't exist if Manufacturers paid more attention to how their products are used in the field.

                        My two cents for what it is worth, if you want to use a metric reticle get a scope with metric adjusters. Front focal plane allows you to use the reticle at any magnification (another hassle you don't have to worry about under pressure) however this comes at the expense of a reticle that expands as you dial up.
                        While I understand your line of thinking, realize that the principle is neither metric nor imperial. A more accurate description might be mil or moa (minute of angle), and both pertain to measuring arcs of a circle. One method uses measurements in mils and the other in minutes (a subset of degrees). As you alluded to, it's easier to use scopes where as reticle and turrets are in agreement, whether it be mil/mil or moa/moa. Hopefully, the apparent trend away from mil reticles coupled with moa turrets will continue.
                        Last edited by Drifter; 09-20-2013, 06:14 AM.
                        Drifter

                        Comment

                        • Klem
                          Chieftain
                          • Aug 2013
                          • 3507

                          #13
                          Originally posted by Drifter View Post
                          While I understand your line of thinking, realize that the principle is neither metric nor imperial. A more accurate description might be mil or moa (minute of angle), and both pertain to measuring arcs of a circle. One method uses measurements in mils and the other in minutes (a subset of degrees). As you alluded to, it's easier to use scopes where as reticle and turrets are in agreement, whether it be mil/mil or moa/moa. Hopefully, the apparent trend away from mil reticles coupled with moa turrets will continue.
                          I stand corrected, degrees and radians are not 'Imperial', more like Babylonian according to Google (you learn something everyday). As for Mils, Charles-Marc Dapples did however base his angular measurement on the Metric system (one Mil subtends one metre at a 1,000 metres).

                          Comment

                          • mongoosesnipe
                            Chieftain
                            • May 2012
                            • 1142

                            #14
                            If you measure the target size I meters you will get distance in meters if you measure the target in yards you will get yards out of the equation that said the mil dot reticle was originally set up for meters but if you are just using your mil dot for basic range estimation and a hold over reference it realy doesn't matter though I do like mil turets with mil dots and I am a big fan of the metric system and think the US needs to get there act together as far as adopting it I don't see it happening anytime soon as people tend to dwell on the idea of converting units in order to understand whats going on and they can not seem to grasp the concept of moving a decimal to convert units within the metric system and I am not even talking about red necks in the woods I am talking about college students taking advanced chemistry classes in 2012 its ridiculous
                            Punctuation is for the weak....

                            Comment

                            • LR1955
                              Super Moderator
                              • Mar 2011
                              • 3355

                              #15
                              Originally posted by Klem View Post
                              Scope manufacturers who market Metric reticles with Imperial turrets need to be rounded-up. This normative pressure to stick to an antiquated measuring system is the bain of US shooters. The mental conversion needed between metric and Imperial when under stress is one less hassle you need, and can be eliminated so easily.

                              Metric reticles go with metric knobs. Imperial reticles (Nightforce do a Mildot equivalent reticle in MOA) go with Imperial knobs. Common sense I know but there are more US scope manufacturers offering Metric/Imperial than there are Metric/Metric or Imperial/Imperial and this thread wouldn't exist if Manufacturers paid more attention to how their products are used in the field.

                              My two cents for what it is worth, if you want to use a metric reticle get a scope with metric adjusters. Front focal plane allows you to use the reticle at any magnification (another hassle you don't have to worry about under pressure) however this comes at the expense of a reticle that expands as you dial up.
                              Klem:

                              How did we survive with the ART and Leupolds? Distances were in meters and increments in minutes! For how long? Sixty years? Just a joke.

                              BTW -- with the Leupold and the M-3 BDC's that were calibrated in hundreds of something with minute clicks between, guys would memorize how many 'clicks' between and divide into 100. This was normally started at 500 or 600 where there are enough clicks where one minute could mean a hit or miss. They may not even know what a minute was. Only that between say 600 and 700 there were six clicks for example so if t hey ranged something at 650 they would put on '6 plus 3'.

                              I do agree that if a fellow wants to use mils as an increment of elevation or windage, get a scope that has mils as increments.

                              LR1955
                              Last edited by LR1955; 09-23-2013, 02:15 PM.

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