A GOB on another board asked:
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<br>"With all the different variables known, and just measuring bullet drop from different ranges can you work backwards to come up with your velocity?"
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<br>Answered him there of course but figured I should answer his question here too. So here's my answer, in case it's of interest to anyone here --
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<br>About fifty years ago, I read of a way to determine mid-range velocity without any special instrument. When I later wanted to read that write-up again, I couldn't find it. So I figured-out, from scratch, how to do it using basic physics and trigonometry (with just a thermometer to read range air temperature and a tape to measure distance, plus some kind of "target" to ring or clang when the bullet hits it). I developed a set of tables too -- rather tediously, in those old precalculator days of pencil, paper, and slide rule. Still have my old write-up, tables and all, somewhere in this midden that I live in. It turns-up now and then, when I'm looking for something else.
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<br>Basically, you find the point horizontally perpendicular to the trajectory, along a line even with the target, where an observer hears the sound of the muzzle blast and the sound of the bullet's impact at the same time. Then you can calculate the time of flight from the target distance, observer distance, and speed of sound -- which varies with air temperature.
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<br>The method works pretty well but is a good bit more bother than it's worth. And it estimates the average velocity between the muzzle and the target, not muzzle or near-muzzle velocity. So now I have a couple of Oehlers and have happily left the old triangulation method deep in my memory and old notes.
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<br>Go with nothing less than or other than an Oehler 33* and don't look back. Or sideways.
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<br>*typo -- meant to say "Oehler 35"
