Help - Figureing out ballastic issues

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  • Sticks
    Chieftain
    • Dec 2016
    • 1922

    Help - Figureing out ballastic issues

    I have a Kestrel w/applied ballistics, and was trying to verify data with JBM ballistics calculator, and neither one agrees with the same data input.

    Not sure where I am screwing up. The differences are fairly large (.2+mil at 700y) and can be the difference between a hit and air ball at longer ranges on a 2 MOA target with my skillset.

    If someone could run the following info on an app, not one of the two above, and post the range data every 50y so I can see if I can get two to agree.

    6.5 Grendel
    1:8 RH
    Bore Height 2.82"
    Zero at 100y
    123 gr ELD
    .506 G1 BC
    1.248 bullet length
    2515 fps @ 6" from muzzle
    Altitude 4880
    latitude 40.4*
    Ammo 70*
    Ambient temp at 80*
    Baro (station pressure) 25.31 inHg
    Humidity 45%

    I know I need to do a grouping at 800 or so to do a calibration..and this is where my head starts to swim a little if the Kestrel will extrapolate based on changing conditions or not.
    Sticks

    Catchy sig line here.
  • Bigs28
    Chieftain
    • Feb 2016
    • 1786

    #2
    I think i entered in everything correctly

    Distance, yards Bullet speed, f/s Vert. correction, MRAD Hor. correction, MRAD
    100.0 2379.9 0.0 0.16
    150.0 2314.0 0.2 0.25
    200.0 2249.0 0.5 0.34
    250.0 2185.4 0.8 0.43
    300.0 2123.0 1.3 0.52
    350.0 2061.7 1.7 0.61
    400.0 2001.3 2.2 0.71
    450.0 1942.3 2.7 0.81
    500.0 1884.5 3.2 0.91
    550.0 1827.4 3.8 1.02
    600.0 1771.7 4.4 1.13
    650.0 1716.9 5.0 1.24
    700.0 1663.4 5.6 1.36
    750.0 1610.9 6.3 1.47
    800.0 1559.4 7.0 1.60
    850.0 1508.9 7.8 1.72
    900.0 1459.6 8.5 1.86
    950.0 1411.1 9.4 1.99
    1000.0 1363.8 10.2 2.13

    Comment

    • Sticks
      Chieftain
      • Dec 2016
      • 1922

      #3
      Thank you Bigs28.

      What app or program did you use?
      Sticks

      Catchy sig line here.

      Comment

      • Bigs28
        Chieftain
        • Feb 2016
        • 1786

        #4
        Strelok

        Comment

        • NugginFutz
          Chieftain
          • Aug 2013
          • 2622

          #5
          Ballistic AE
          Input Parameters


          BC Bullet
          Weight
          Muzzle
          Velocity
          Zero
          Range
          Sight
          Height
          LOS
          Angle
          Altitude
          Pressure Temp RH Wind
          Velocity
          Wind
          Angle
          Zero
          Altitude
          Zero
          Pressure
          Zero
          Temp
          Zero
          RH
          Min.
          PBR
          Max.
          PBR
          Miller Stability
          2.35
          Bullet Trajectory

          Range
          (yards)
          Drop
          (in)
          Drop
          (mrad)
          Wind.
          (in)
          Wind.
          (mrad)
          Veloc.
          (fps)
          Energy
          (ft-lbs)
          Time
          (sec)
          0 -2.84 0.00 0.00 0.00 2515 1728 0.00
          50 -0.69 -0.38 -0.04 -0.02 2445 1632 0.06
          100 -0.00 -0.00 0.02 0.01 2375 1540 0.12
          150 -0.86 -0.16 0.22 0.04 2307 1453 0.19
          200 -3.37 -0.47 0.61 0.08 2239 1369 0.25
          221 -5.02 -0.63 0.85 0.11 2211 1333 0.28
          250 -7.62 -0.85 1.24 0.14 2173 1289 0.32
          300 -13.73 -1.27 2.18 0.20 2108 1213 0.39
          350 -21.80 -1.73 3.48 0.28 2044 1141 0.46
          400 -31.96 -2.22 5.23 0.36 1981 1071 0.54
          450 -44.36 -2.74 7.45 0.46 1919 1006 0.61
          500 -59.13 -3.28 10.13 0.56 1859 944 0.69
          550 -76.43 -3.86 13.29 0.67 1800 885 0.78
          600 -96.43 -4.46 16.90 0.78 1742 829 0.86
          650 -119.31 -5.10 20.96 0.90 1686 776 0.95
          700 -145.27 -5.76 25.46 1.01 1632 727 1.04
          750 -174.51 -6.46 30.38 1.12 1579 680 1.13
          800 -207.27 -7.20 35.71 1.24 1527 637 1.23
          850 -243.77 -7.97 41.43 1.35 1478 596 1.33
          900 -284.28 -8.77 47.53 1.47 1430 559 1.43
          950 -329.07 -9.62 53.97 1.58 1385 524 1.54
          1000 -378.42 -10.51 60.74 1.69 1342 491 1.65
          1050 -432.64 -11.44 67.80 1.79 1301 462 1.76
          1100 -492.02 -12.42 75.13 1.90 1262 435 1.88
          1150 -556.91 -13.45 82.70 2.00 1226 410 2.00
          1200 -627.62 -14.53 90.47 2.09 1193 388 2.12
          Range Drop Drop Wind. Wind. Veloc. Energy Time
          Last edited by NugginFutz; 07-25-2017, 06:27 PM.
          If it's true that we are here to help others, then what exactly are the others here for?

          Comment

          • StoneHendge
            Chieftain
            • May 2016
            • 2009

            #6
            Don't know if you or anyone else did it or if you programs do it automatically, but if your using station pressure, you need to zero the altitude. You should also really use a G7 model to go out to 700/800 yards and beyond. Maybe one (both?) program are making adjustments? G1 declines with velocity.

            I used a G7 of .255 for ELD I pulled off the World Wide Web somewhere when I was breaking in my barrel and it seemed close enough
            Let's go Brandon!

            Comment

            • NugginFutz
              Chieftain
              • Aug 2013
              • 2622

              #7
              Originally posted by StoneHendge View Post
              Don't know if you or anyone else did it or if you programs do it automatically, but if your using station pressure, you need to zero the altitude. You should also really use a G7 model to go out to 700/800 yards and beyond. Maybe one (both?) program are making adjustments? G1 declines with velocity.

              I used a G7 of .255 for ELD I pulled off the World Wide Web somewhere when I was breaking in my barrel and it seemed close enough
              In the case of BAE, station pressure overrides ASL. I only plugged in G1 for the sake of consistency with the OP's data. By all means, use a G7 model when appropriate (most modern boat tail projectiles). G1 is still quite adequate for most flat based bullets.
              If it's true that we are here to help others, then what exactly are the others here for?

              Comment

              • bj139
                Chieftain
                • Mar 2017
                • 1968

                #8
                I thought it would be about 10 MRAD at 1000 yds.

                Comment

                • Sticks
                  Chieftain
                  • Dec 2016
                  • 1922

                  #9
                  Now I have 4 drop charts that don't agree. All within .36...seems like a lot.

                  700 yards drop in mil
                  Applied Ballistics -5.58 (did not change with the BC changed to a G7 BC of .255)
                  JBM -5.4 (changes to 5.7 if I zero the altitude with station pressure)
                  Strelok -5.6
                  Ballistic AE -5.76

                  Ultimately I need to shoot at that range, or something close to and get dialed in and tweak numbers until they match POI.

                  Just kind of stunned that there is that much variance between 4 flavors.

                  Does one throw out the high and low? Puts Applied Ballistics and Strelok side by side at 700, more variation at 1k (Strelok 10.2 / AB 10.29)
                  Last edited by Sticks; 07-25-2017, 10:49 PM.
                  Sticks

                  Catchy sig line here.

                  Comment

                  • StoneHendge
                    Chieftain
                    • May 2016
                    • 2009

                    #10
                    Originally posted by NugginFutz View Post
                    In the case of BAE, station pressure overrides ASL. I only plugged in G1 for the sake of consistency with the OP's data. By all means, use a G7 model when appropriate (most modern boat tail projectiles). G1 is still quite adequate for most flat based bullets.
                    Yeah - every program is different. I use Shooter and you need to make the pressure absolute. Otherwise my 123 gr Scenar wouldn't be going subsonic until 1700 yards at a station pressure of 23.9 adjusted for an altitude of 6600ft. Which would rock! Makes me want to put a target on top of a 14er and climb the next one over.....
                    Let's go Brandon!

                    Comment

                    • NugginFutz
                      Chieftain
                      • Aug 2013
                      • 2622

                      #11
                      Originally posted by Sticks View Post
                      ...
                      Applied Ballistics -5.58 (did not change with the BC changed to a G7 BC of .255)
                      ...
                      Ultimately I need to shoot at that range, or something close to and get dialed in and tweak numbers until they match POI.

                      Just kind of stunned that there is that much variance between 4 flavors.

                      Does one throw out the high and low? Puts Applied Ballistics and Strelok side by side at 700, more variation at 1k (Strelok 10.2 / AB 10.29)
                      If your numbers didn't change with the .255 G7 BC, you've gone wrong somewhere.

                      Here's BAE with a .255 G7.

                      Bullet Trajectory

                      Range
                      (yards)
                      Drop
                      (in)
                      Drop
                      (mrad)
                      Wind.
                      (in)
                      Wind.
                      (mrad)
                      Veloc.
                      (fps)
                      Energy
                      (ft-lbs)
                      Time
                      (sec)
                      0 -2.84 0.00 0.00 0.00 2515 1728 0.00
                      50 -0.69 -0.38 -0.04 -0.02 2445 1632 0.06
                      100 -0.00 -0.00 0.02 0.01 2375 1540 0.12
                      150 -0.86 -0.16 0.22 0.04 2307 1453 0.19
                      200 -3.37 -0.47 0.61 0.08 2240 1370 0.25
                      221 -5.02 -0.63 0.85 0.11 2212 1334 0.28
                      250 -7.62 -0.85 1.24 0.14 2174 1290 0.32
                      300 -13.72 -1.27 2.17 0.20 2109 1214 0.39
                      350 -21.79 -1.73 3.47 0.28 2045 1142 0.46
                      400 -31.95 -2.22 5.21 0.36 1982 1073 0.54
                      450 -44.33 -2.74 7.42 0.46 1921 1007 0.61
                      500 -59.09 -3.28 10.10 0.56 1860 945 0.69
                      550 -76.37 -3.86 13.25 0.67 1800 885 0.78
                      600 -96.35 -4.46 16.87 0.78 1741 828 0.86
                      650 -119.22 -5.09 20.95 0.90 1683 773 0.95
                      700 -145.18 -5.76 25.48 1.01 1625 721 1.04
                      750 -174.45 -6.46 30.47 1.13 1569 672 1.13
                      800 -207.28 -7.20 35.89 1.25 1513 625 1.23
                      850 -243.93 -7.97 41.74 1.36 1458 581 1.33
                      900 -284.70 -8.79 48.01 1.48 1404 539 1.44
                      950 -329.90 -9.65 54.68 1.60 1352 499 1.55
                      1000 -379.89 -10.55 61.73 1.71 1300 462 1.66
                      1050 -435.07 -11.51 69.15 1.83 1250 427 1.78
                      1100 -495.85 -12.52 76.89 1.94 1201 394 1.90
                      1150 -562.69 -13.59 84.94 2.05 1154 364 2.03
                      1168 -589.79 -14.01 88.06 2.09 1139 353 2.08
                      1200 -636.11 -14.72 93.24 2.16 1114 339 2.16
                      Range Drop Drop Wind. Wind. Veloc. Energy Time
                      My experiences with BAE have all been positive. It has always been quite close when my data is good. Just be certain your MV is corrected for being measured 6" (inches) from the muzzle. I question this only because that is either too close for an optical Chronograph or seems a bit far for a magnetospeed.
                      If it's true that we are here to help others, then what exactly are the others here for?

                      Comment

                      • Sticks
                        Chieftain
                        • Dec 2016
                        • 1922

                        #12
                        Originally posted by StoneHendge View Post
                        Yeah - every program is different. I use Shooter and you need to make the pressure absolute. Otherwise my 123 gr Scenar wouldn't be going subsonic until 1700 yards at a station pressure of 23.9 adjusted for an altitude of 6600ft. Which would rock! Makes me want to put a target on top of a 14er and climb the next one over.....
                        ShootersCalculator (I am guessing the same one) spit out a number closer to JBM of 5.37.

                        Originally posted by NugginFutz View Post
                        If your numbers didn't change with the .255 G7 BC, you've gone wrong somewhere.

                        Here's BAE with a .255 G7.

                        Bullet Trajectory

                        Range
                        (yards)
                        Drop
                        (in)
                        Drop
                        (mrad)
                        Wind.
                        (in)
                        Wind.
                        (mrad)
                        Veloc.
                        (fps)
                        Energy
                        (ft-lbs)
                        Time
                        (sec)
                        0 -2.84 0.00 0.00 0.00 2515 1728 0.00
                        50 -0.69 -0.38 -0.04 -0.02 2445 1632 0.06
                        100 -0.00 -0.00 0.02 0.01 2375 1540 0.12
                        150 -0.86 -0.16 0.22 0.04 2307 1453 0.19
                        200 -3.37 -0.47 0.61 0.08 2240 1370 0.25
                        221 -5.02 -0.63 0.85 0.11 2212 1334 0.28
                        250 -7.62 -0.85 1.24 0.14 2174 1290 0.32
                        300 -13.72 -1.27 2.17 0.20 2109 1214 0.39
                        350 -21.79 -1.73 3.47 0.28 2045 1142 0.46
                        400 -31.95 -2.22 5.21 0.36 1982 1073 0.54
                        450 -44.33 -2.74 7.42 0.46 1921 1007 0.61
                        500 -59.09 -3.28 10.10 0.56 1860 945 0.69
                        550 -76.37 -3.86 13.25 0.67 1800 885 0.78
                        600 -96.35 -4.46 16.87 0.78 1741 828 0.86
                        650 -119.22 -5.09 20.95 0.90 1683 773 0.95
                        700 -145.18 -5.76 25.48 1.01 1625 721 1.04
                        750 -174.45 -6.46 30.47 1.13 1569 672 1.13
                        800 -207.28 -7.20 35.89 1.25 1513 625 1.23
                        850 -243.93 -7.97 41.74 1.36 1458 581 1.33
                        900 -284.70 -8.79 48.01 1.48 1404 539 1.44
                        950 -329.90 -9.65 54.68 1.60 1352 499 1.55
                        1000 -379.89 -10.55 61.73 1.71 1300 462 1.66
                        1050 -435.07 -11.51 69.15 1.83 1250 427 1.78
                        1100 -495.85 -12.52 76.89 1.94 1201 394 1.90
                        1150 -562.69 -13.59 84.94 2.05 1154 364 2.03
                        1168 -589.79 -14.01 88.06 2.09 1139 353 2.08
                        1200 -636.11 -14.72 93.24 2.16 1114 339 2.16
                        Range Drop Drop Wind. Wind. Veloc. Energy Time
                        My experiences with BAE have all been positive. It has always been quite close when my data is good. Just be certain your MV is corrected for being measured 6" (inches) from the muzzle. I question this only because that is either too close for an optical Chronograph or seems a bit far for a magnetospeed.
                        Yours is still showing 5.76 for 700y

                        Magneto speed was the Chrono, I split the difference between the two sensors (Front and Rear)
                        Last edited by Sticks; 07-25-2017, 11:02 PM.
                        Sticks

                        Catchy sig line here.

                        Comment

                        • NugginFutz
                          Chieftain
                          • Aug 2013
                          • 2622

                          #13
                          Originally posted by StoneHendge View Post
                          Yeah - every program is different. I use Shooter and you need to make the pressure absolute. Otherwise my 123 gr Scenar wouldn't be going subsonic until 1700 yards at a station pressure of 23.9 adjusted for an altitude of 6600ft. Which would rock! Makes me want to put a target on top of a 14er and climb the next one over.....
                          Yeah, but how do you breathe? I've been up a few, including Pike's Peak. Just driving made me light headed.
                          If it's true that we are here to help others, then what exactly are the others here for?

                          Comment

                          • LR1955
                            Super Moderator
                            • Mar 2011
                            • 3355

                            #14
                            Originally posted by Sticks View Post
                            Now I have 4 drop charts that don't agree. All within .36...seems like a lot.

                            700 yards drop in mil
                            Applied Ballistics -5.58 (did not change with the BC changed to a G7 BC of .255)
                            JBM -5.4 (changes to 5.7 if I zero the altitude with station pressure)
                            Strelok -5.6
                            Ballistic AE -5.76

                            Ultimately I need to shoot at that range, or something close to and get dialed in and tweak numbers until they match POI.

                            Just kind of stunned that there is that much variance between 4 flavors.

                            Does one throw out the high and low? Puts Applied Ballistics and Strelok side by side at 700, more variation at 1k (Strelok 10.2 / AB 10.29)
                            Sticks:

                            If all are within .36 m, they are within about around a minute of each other. Find what their average is and use what ever program is closest to that average.

                            LR55

                            Comment

                            • Sticks
                              Chieftain
                              • Dec 2016
                              • 1922

                              #15
                              Quick look at the numbers shows a 15" variance at 700y between the high and low.

                              I need to do some more reading, and shooting. This match that I am shooting next weekend is looking sketchy for those targets past 500 unless I get this data and math solved on my end.
                              Sticks

                              Catchy sig line here.

                              Comment

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