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Line of sight v Parabola

iceracerxiceracerx Member Posts: 8,860 ✭✭✭
edited June 2017 in Ask the Experts
The recent news of a new long range shot by a sniper in a combat zone has presented us with some general information: linear distance, approx flight time, etc.

The general time of flight is said to be '10 seconds'. One expert (I hope he reads this and replies) said the flight time was approx 7.59 seconds to cover the reported 3,540 meters.

So, given the reported round (50 BMG), was that 3,540 meters 'line of sight' or is that the actual parabolic arch of the bullet path, (My ballistic calculator doesn't allow for 50 BMG. Guess I need a new one) and if not, what was the distance of the bullet path? (I'm sure I could find my old Physics book and look up the 'how high @ what time' formula but I'm feeling lazy tonight)

Thanks to all. The more I read about this the more it seems to have been a equipment test of some sort. Drones, video crew, etc. Interesting times.

Comments

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    rufe-snowrufe-snow Member Posts: 18,650 ✭✭✭
    edited November -1
    Not done manually any more, specially at 2 miles. Very sophisticated computerized sights, are attached to the rifles. Even when all pertinent data are entered into the computer. Not going to be a sure shot, specially at 2 miles. See photo below.




    tp2-firing.jpg
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    Hawk CarseHawk Carse Member Posts: 4,369 ✭✭✭
    edited November -1
    I have not shot farther than 1000 yards but I know in that case that it is line of sight, not bullet path that is the measure of range.
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    charliemeyer007charliemeyer007 Member Posts: 6,579 ✭✭✭
    edited November -1
    10 seconds of free fall is like 1500 ft. I'm sure the distance was laser checked several times. Still a great job of doping the wind.

    You have to shoot at them in order to hit them.
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    NeoBlackdogNeoBlackdog Member Posts: 16,677 ✭✭✭✭
    edited November -1
    If you calculate it as the length of an arc of a circle, using 11,319' as the length of the chord, and 693' as the height of the arc (bullet drop) then the length of the arc works out to about 11,432'. Only 113 feet longer than the line of sight. (Not as much as I would have guessed!)
    This is not exact, as it is calculating the arc for a perfect circle, not the parabolic arc that a bullet would take.
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    navc130navc130 Member Posts: 1,204 ✭✭✭
    edited November -1
    Shooting distances have traditionally always been given as line-of-sight. Distance along the flight arc would be a meaningless figure (I think).
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    nononsensenononsense Member Posts: 10,928 ✭✭✭✭
    edited November -1
    iceracerx,

    All calculations which we perform currently are based on line of sight because that's all we can measure. The calculations will generally list the dimensions of the flight path in parabolic form.

    The calculations I ran as a check on the information given in several reports was generated by a 'plug-n-play' type of calculator and then compared to my data which was generated by actual shooting at 2 miles. The difference not specifically noted is that I use extremely high BC custom made bullets and the Canadians are supposedly using the 750 grain AMAX. I did adjust the calculator for their muzzle velocity and the BC of the AMAX plus the atmospheric conditions of that shot. The amazing parts to this shot are twofold:

    The massive increase in the target distance over the previous record.

    The accurate travel of the bullet through 900 yards of transonic/subsonic distance.

    Here is the link to that calculator:

    http://www.shooterscalculator.com/ballistic-trajectory-chart.php?pl=%5BPreset

    There is now a report stating that a drone was positioned over the target site along with a video team of observers much closer to the target than the sniper team. The sniper team was positioned on top of a 10-story high rise.

    My question is still, why all the prep and coverage for such a low-level kill shot? The only viable answer I can deduce is that the Canadians were testing some new ammunition or equipment specifically for these extreme long range shots. Think DARPA.

    Best.
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