Re: Amazing trajectory calculations
<span style="font-weight: bold">OFF TOPIC GUYS, STOP ARGUING HERE OR GO AWAY</span> thank you.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Brown Dog</div><div class="ubbcode-body">
JL,
Got to start my answer with a question: What vertical dispersion did the dopplered shots show?
Because of all the interacting and unpredictable variables between shots (minor MV changes, slightly different bullet weights, slightly different bullet shapes, a 0.1 knot tailwind change etc) or between strings of shots (the slightly warmer barrel, the different bore surface /fouling compared to the last string, a 4mB pressure change etc) to claim to define a particular ammunition's drop to an exact value at 1.5km is....err, optimistic.
Each round in a string will land differently to the last. Thinking only in vertical terms; the rounds will have a normal (Gaussian)distribution. Some will land high, some will land low; 68% will land within one standard deviation of the mean POI....and it’s likely that that mean POI will be different from string to string and, especially, occasion to occasion.
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BrownDog, thanks for your reply
Unfortunately I dont have doppler test details available.
Personally never even seen or tested radar system.
Alltough I know peoples who have done this for living. With 338LM too. Will ask for sure next time when I see those quys.
Still, I´d assume that when shooting test with radar, they are looking for average too. MV changes in test can be calculated to match trajectory in desired slightly lower or higher "correct" MV.
All other variables, such as slight bullet weight changes basically doesent matter after all since tester is looking for average..say at xx or xxx shot strings anyway.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Brown Dog</div><div class="ubbcode-body">
I would say that any prediction that is within one standard deviation of the mean is ‘within tolerance’ ..or ‘close enough for government work’….because you’ve predicted data that will put your shot within the zone in which 68% of all shots will hit.
..and I rather suspect that this 7.5cm ‘error’ will be well inside one SD for rifle fire at 1.5km!
...and thus, in real world terms, I suspect 7.5cm at 1.5km cannot be sensibly described as an 'error'.
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Yes, you´re right and I agree- 0.05mrad@1500 is minimal POI shift. SD can cause same or larger spread- among many other (shorter range) insignificant things too.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Brown Dog</div><div class="ubbcode-body">
(PS ...I spent some time at Rovajärvi several years back; great fun, although it was some time before I could look at vodka again!)
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Rovajärvi....hmmm...artillery shooting area there, right?
