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Range Report Interpolating performance at the between ranges?

earthquake

Area Man
Supporter
Full Member
Minuteman
  • Jul 30, 2009
    3,030
    2,539
    USA
    This past Monday I went shooting. Took my 6.5Creed to the DOW range near Buena Vista, CO and banged some steel. My cold bore on the 600 yard jackrabbit was a hit, so I was pretty happy with that! Follow up shot to confirm hit too.

    Temps were ~33F, with sunny skies, ASL is ~7,000' with maybe 30% humidity. Wind was light in the morning, 2 - 3 mph then picking up to ~10 mph later and gusting. Anyway, I was able to get DOPE/come-ups from 200 - 600 yards, then at 925 and 1,025 yards. Unfortunately, there are no targets between 600 and 925 yards. Based off my drops, can I reliable interpolate what I should have for drops between 600 and 925? That's a rather large hole in my data that I don't think I can find another place to figure it out.

    Is this what "truing" my ballistics is? I was only able to get chrony data on two shots before my chrony crapped the bed. Shooting factory Hornady Amax 140's, I averaged 2,825 fps on those shots with the chrony at least 10' from my muzzle.

    Here's my DOPE:

    200 = -0.4 mil
    345 = -1.3 mil
    495 = -2.5 mil
    500 = -2.6 mil
    535 = -2.9 mil
    550 = -3.0 mil
    600 = -3.5 mil
    ...................
    ...................
    925(-ish) = -7.0 mil (average from a few LRF readings)
    1,025(-ish) = -7.7 mil (average from a few LRF readings)

    I did a quick & dirty plot of this in Excel and got a curve/line...any idea if that line would give accurate info? It's somewhat linear.

    I was using iSnipe and it was giving different results than what I was actually seeing in the field. That may be due to MV differences they have loaded in the factory Amax ammo you can select in the ammo library, but I'm not sure.

    So, is there a reliable way for me to get those data points between 600 and 925 yards based on my DOPE, and not from what my ballistics softward is telling me, which I've found is not all that accurate?
     
    JBM - Calculations - Trajectory

    Plug in the data you do have and see if you can get it to match your known DOPE. Here's what I got

    <pre>
    Calculated Table
    Range Drop Drop Windage Windage Velocity Mach Energy Time Lead Lead
    (yd) (in) (mil) (in) (mil) (ft/s) (none) (ft•lbs) (s) (in) (mil)
    0 -1.5 *** 0.0 *** 2829.4 2.600 2488.3 0.000 0.0 ***
    100 -0.0 -0.0 0.4 0.1 2698.2 2.480 2262.9 0.109 19.1 5.3
    200 -3.3 -0.5 1.8 0.3 2571.0 2.363 2054.4 0.222 39.2 5.4
    300 -11.8 -1.1 4.2 0.4 2447.4 2.249 1861.6 0.342 60.2 5.6
    400 -26.2 -1.8 7.7 0.5 2327.2 2.139 1683.3 0.468 82.3 5.7
    500 -46.9 -2.6 12.3 0.7 2210.4 2.031 1518.6 0.600 105.6 5.9
    600 -74.8 -3.5 18.2 0.8 2096.9 1.927 1366.6 0.739 130.1 6.0
    700 -110.6 -4.4 25.4 1.0 1986.7 1.826 1226.8 0.886 156.0 6.2
    800 -155.2 -5.4 34.0 1.2 1880.1 1.728 1098.6 1.042 183.3 6.4
    900 -209.7 -6.5 44.3 1.4 1777.1 1.633 981.6 1.206 212.2 6.6
    1000 -275.2 -7.6 56.2 1.6 1678.1 1.542 875.3 1.380 242.8 6.7
    1100 -353.0 -8.9 69.9 1.8 1583.5 1.455 779.3 1.564 275.2 6.9
    1200 -444.7 -10.3 85.6 2.0 1493.6 1.373 693.4 1.759 309.6 7.2
    1300 -552.1 -11.8 103.4 2.2 1409.0 1.295 617.0 1.966 346.0 7.4
    1400 -676.9 -13.4 123.3 2.4 1330.2 1.222 549.9 2.185 384.6 7.6
    1500 -821.5 -15.2 145.5 2.7 1257.9 1.156 491.8 2.417 425.4 7.9
    1600 -988.1 -17.2 170.0 3.0 1192.7 1.096 442.1 2.663 468.6 8.1
    1700 -1179.1 -19.3 196.8 3.2 1135.3 1.043 400.6 2.921 514.1 8.4
    1800 -1397.2 -21.6 225.8 3.5 1086.0 0.998 366.6 3.192 561.7 8.7
    1900 -1644.9 -24.0 256.9 3.8 1044.2 0.960 338.9 3.474 611.5 8.9
    2000 -1924.6 -26.7 289.9 4.0 1008.7 0.927 316.2 3.768 663.1 9.2
    2100 -2238.7 -29.6 324.6 4.3 978.0 0.899 297.3 4.071 716.5 9.5
    2200 -2589.5 -32.7 361.0 4.6 951.0 0.874 281.1 4.383 771.5 9.7
    2300 -2979.0 -36.0 398.9 4.8 926.9 0.852 267.0 4.705 828.1 10.0
    2400 -3409.5 -39.5 438.3 5.1 905.1 0.832 254.6 5.035 886.1 10.3
    2500 -3883.2 -43.1 479.1 5.3 885.0 0.813 243.4 5.373 945.7 10.5
    </pre>
     
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