So I read a few other posts about this subject but I'm still a little confused. When you are shooting down hill at a target how do you account for the angle in the trajectory? Do you adjust your scope so that you are basically shooting the straight line distance?
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Shooting at an angle
- Thread starter immcpat
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Re: Shooting at an angle
You are adjusting your dope for the base line distance. So if you think about your shooting situation like a cutout view from the side, you are making a right triangle. The straight line distance is the hypotenuse(longest side o the triangle. The vertical line of the triangle is your elevation difference. The Base line distance is your unknown that you are solving for. Use the Pythagorean theorem to solve for the unknown (square root of(straight line distance squared-elevation distance squared))This will give you the distance to dial onto your scope for elevation. Hope that helped, i couldn't figure out how to type mathematical functions.
You are adjusting your dope for the base line distance. So if you think about your shooting situation like a cutout view from the side, you are making a right triangle. The straight line distance is the hypotenuse(longest side o the triangle. The vertical line of the triangle is your elevation difference. The Base line distance is your unknown that you are solving for. Use the Pythagorean theorem to solve for the unknown (square root of(straight line distance squared-elevation distance squared))This will give you the distance to dial onto your scope for elevation. Hope that helped, i couldn't figure out how to type mathematical functions.
Re: Shooting at an angle
If you are shooting at a 1000 yard target, you will not make a 1000 yard adjustment on your scope! I use two different formulas for angle shooting.
1. <span style="font-weight: bold">Original distance X angle cosine = angle yards</span>
(Make new adjustment on your scope to reflect the new angle yards)
Ex: Shooting a target at 600 yards at a 25 degree angle will reflect the following..... 600yds X .906 = 544yds
So you would make the adjustment on your scope for 544 yards.
2. <span style="font-weight: bold">Original dope X angle cosine = angled dope</span>
Ex: 900 yard shot at 45 degree angle your original 900 yard dope may be around 30 MOA so..... 30 X .707 = 21.5 MOA adjustment.
Very Simple. Hope this helps.
If you are shooting at a 1000 yard target, you will not make a 1000 yard adjustment on your scope! I use two different formulas for angle shooting.
1. <span style="font-weight: bold">Original distance X angle cosine = angle yards</span>
(Make new adjustment on your scope to reflect the new angle yards)
Ex: Shooting a target at 600 yards at a 25 degree angle will reflect the following..... 600yds X .906 = 544yds
So you would make the adjustment on your scope for 544 yards.
2. <span style="font-weight: bold">Original dope X angle cosine = angled dope</span>
Ex: 900 yard shot at 45 degree angle your original 900 yard dope may be around 30 MOA so..... 30 X .707 = 21.5 MOA adjustment.
Very Simple. Hope this helps.
Re: Shooting at an angle
MANIMAL's way will get you the same answer, just carry a protractor with some string tied to a rock or something heavy. Point the straight edge of the protractor at your target and pinch the string where it hangs. Find the cosine of that angle and input it into the equation, and bammm there is your range/dope.
MANIMAL's way will get you the same answer, just carry a protractor with some string tied to a rock or something heavy. Point the straight edge of the protractor at your target and pinch the string where it hangs. Find the cosine of that angle and input it into the equation, and bammm there is your range/dope.
Re: Shooting at an angle
In short it all depends on how extreme your circumstances are. Ballistics software will calculate all effects accurately here. If you need very accurate corrections (inches) at ranges beyond a couple hundred yards at higher shooting inclination/declination angles, say 30 deg or above, you must use ballistics software. There are a variety of hand/calculator correction methods you can use, some more difficult than others. But again at the extremes, all of the hand calculated techniques suffer in accuracy.
As for the simpler corrections the best one should be calculated using the actual line of sight range ("hypotenuse" distance) as if it was a level shot. Then calculate the elevation dope for a fictitious shot of that same distance under the same circumstances. Lastly multiply that dope value by the cosine of the true shots inclination angle. This is the 2nd method suggested by MANIMAL. The horizontal "projection" method suggested above is not nearly as accurate!
There is a very thorough discussion here.
In short it all depends on how extreme your circumstances are. Ballistics software will calculate all effects accurately here. If you need very accurate corrections (inches) at ranges beyond a couple hundred yards at higher shooting inclination/declination angles, say 30 deg or above, you must use ballistics software. There are a variety of hand/calculator correction methods you can use, some more difficult than others. But again at the extremes, all of the hand calculated techniques suffer in accuracy.
As for the simpler corrections the best one should be calculated using the actual line of sight range ("hypotenuse" distance) as if it was a level shot. Then calculate the elevation dope for a fictitious shot of that same distance under the same circumstances. Lastly multiply that dope value by the cosine of the true shots inclination angle. This is the 2nd method suggested by MANIMAL. The horizontal "projection" method suggested above is not nearly as accurate!
There is a very thorough discussion here.
Re: Shooting at an angle
^^^Swamp2, The "Horizontal projection" method, as you put it, will literally get you the same EXACT answer. Both equations are solving for the Flat ground(base line) distance just using geometry instead of trigonometry. So please explain how one is more "accurate" than the other? I agree that the cosine equation is more simple to use given a protractor or rangefinder w/shooting angle display, but to say that one is more "accurate" than the other is simply incorrect.
^^^Swamp2, The "Horizontal projection" method, as you put it, will literally get you the same EXACT answer. Both equations are solving for the Flat ground(base line) distance just using geometry instead of trigonometry. So please explain how one is more "accurate" than the other? I agree that the cosine equation is more simple to use given a protractor or rangefinder w/shooting angle display, but to say that one is more "accurate" than the other is simply incorrect.
Re: Shooting at an angle
+1 shooter app.
You can find the angel you are shooting with this app. Then it will use the angel to better your data.
+1 shooter app.
You can find the angel you are shooting with this app. Then it will use the angel to better your data.
Re: Shooting at an angle
Large angles at short distances have the greatest effect.
Multiplying the actual range times the cosine of the angle, then using the dope for that range is called the Rifleman's Rule. But that won't work for shots at long distances.
The Improved Rifleman's Rule is used to multiply the dope for the actual range by the cosine of the angle. It's significantly more accurate.
http://www.exteriorballistics.com/ebexplained/article1.html
Large angles at short distances have the greatest effect.
Multiplying the actual range times the cosine of the angle, then using the dope for that range is called the Rifleman's Rule. But that won't work for shots at long distances.
The Improved Rifleman's Rule is used to multiply the dope for the actual range by the cosine of the angle. It's significantly more accurate.
http://www.exteriorballistics.com/ebexplained/article1.html
Re: Shooting at an angle
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CheechTheDon</div><div class="ubbcode-body">^^^Swamp2, The "Horizontal projection" method, as you put it, will literally get you the same EXACT answer. Both equations are solving for the Flat ground(base line) distance just using geometry instead of trigonometry. So please explain how one is more "accurate" than the other? I agree that the cosine equation is more simple to use given a protractor or rangefinder w/shooting angle display, but to say that one is more "accurate" than the other is simply incorrect. </div></div>
The formulae and results are different. Each uses a different base distance along with the cosine correction, so of course they will give different results. That should be plainly obvious but if you need to see a worked example consult the link I provided (same one as provided just above). The accuracy claim comes from comparing to a complete 3DOF model which can solve very precisely for all angle and gravitational effects. Again see example quoted. Cheers.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: CheechTheDon</div><div class="ubbcode-body">^^^Swamp2, The "Horizontal projection" method, as you put it, will literally get you the same EXACT answer. Both equations are solving for the Flat ground(base line) distance just using geometry instead of trigonometry. So please explain how one is more "accurate" than the other? I agree that the cosine equation is more simple to use given a protractor or rangefinder w/shooting angle display, but to say that one is more "accurate" than the other is simply incorrect. </div></div>
The formulae and results are different. Each uses a different base distance along with the cosine correction, so of course they will give different results. That should be plainly obvious but if you need to see a worked example consult the link I provided (same one as provided just above). The accuracy claim comes from comparing to a complete 3DOF model which can solve very precisely for all angle and gravitational effects. Again see example quoted. Cheers.
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