"Elevation Angle" (ballistic calculator feature): Wanted

[Brians356]

I am looking for an online ballistic calculator that shows "elevation angle", i.e. the angle formed by a horizontal line and the bore axis. Think of it as "launch angle" for a desired POI at a particular range.

Anyone know of an online calculator (not an "app") that displays "elevation angle"?
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[CharlieNC]

The calculated moa plus scope base moa should be in the ballpark unless I'm missing something?

 

[Fairchaser]

StrelokPro has this feature but it’s not free.

 

[Brians356]

The calculated moa plus scope base moa should be in the ballpark unless I'm missing something?

Which online calculator are you referring to showing calculated MOA? I'll take a look ...
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[Brians356]

StrelokPro has this feature but it’s not free.

And it's a phone app. No can do.
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[RegionRat]

https://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

ETA: look part way into the input section and you will see Elevation and if you see the question mark nearby it takes you to the definitions page for that entry. Circle back here if you need more help.

 

[Brians356]

https://www.jbmballistics.com/cgi-bin/jbmtraj-5.1.cgi

ETA: look part way into the input section and you will see Elevation and if you see the question mark nearby it takes you to the definitions page for that entry. Circle back here if you need more help.

Yes! I forgot about the JBM calculator, have used it a lot years ago.

In Input Data I selected Elevation = 0.000 MOA. (That's for uphill/downhill corrections.)

Also selected Sight Height = 0.000.

In Output Data, for a 300 yard zero, it shows: Elevation: 7.070 MOA.

Now I just need to convert MOA to simple degrees: 7.070 / 60 = 0.1178 degrees.

Thanks!
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[Brians356]

Yes! I forgot about the JBM calculator, have used it a lot years ago.

In Input Data I selected Elevation = 0.000 MOA. (That's for uphill/downhill corrections.)

Also selected Sight Height = 0.000.

In Output Data, for a 300 yard zero, it shows: Elevation: 7.070 MOA.

Now I just need to convert MOA to simple degrees: 7.070 / 60 = 0.1178 degrees.

Thanks!
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FWIW the Elevation Angle allows me to calculate how far above POI, on the plane of the target backer, the bore axis is pointed. In my particular scenario ( G1 BC .480, MV 2850 fps, std conditions) the bore axis is pointed 22.2" above POI at 300 yards.
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[Brians356]

PS This exercise was to test the NRA's rule of thumb that the bore axis points above POI ~4x the max midrange path. In my scenario, JBM lists the max path (mislabeled "Drop"!) as 6.0 inches @160 yds. So the NRA rule yields 24" vs calculated 22.2". Not a bad approximation, but in my example it's actually 3.7 x max path.

PPS Very interesting: If you take JBM's calculated TOF = 0.352 secs, and use that to calculate how far a simple free-falling body drops, it's 0.6071296 meters, or 23.903 inches. That's nearly exactly the 24" the NRA rule produced! But of course, a bullet through air is not a simple free-falling body in a vacuum.
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[RegionRat]

PPS Very interesting: If you take JBM's calculated TOF = 0.352 secs, and use that to calculate how far a simple free-falling body drops, it's 0.6071296 meters, or 23.903 inches. That's nearly exactly the 24" the NRA rule produced! But of course, a bullet through air is not a simple free-falling body in a vacuum.

Yes, but also keep in mind that the terminal velocity and drag are related to the density of the medium, so in air it takes a falling small caliber bullet a long way to create significant drag. Not a big difference between vacuum and short distances like a few feet in that context.

 

[Brians356]

Yes, but also keep in mind that the terminal velocity and drag are related to the density of the medium, so in air it takes a falling small caliber bullet a long way to create significant drag. Not a big difference between vacuum and short distances like a few feet in that context.

Sure. But of course that's not the context here, and my comment was a mere aside, a caution against oversimplifying. The effect of aerodynamics on a speeding bullet through that same medium are real. A couple of inches at 300 yards is small but not insignificant.
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[RegionRat]

Sorry if that wasn't clear.
What I meant was that if you were to straight drop a small caliber bullet a distance of only 24" in air or vacuum, you could hardly see the difference because drag on that bullet and velocity are related to air density and speed, which isn't high enough after only 24" to make a significant difference in a 1G gravity.
Not that shooting to 300 was the same as a straight drop of 24".

 

[Brians356]

Sorry if that wasn't clear.
What I meant was that if you were to straight drop a small caliber bullet a distance of only 24" in air or vacuum, you could hardly see the difference because drag on that bullet and velocity are related to air density and speed, which isn't high enough after only 24" to make a significant difference in a 1G gravity.
Not that shooting to 300 was the same as a straight drop of 24".

Oh I understood you, but ... oh, never mind.
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