Great video. Been looking for hours on how to find a simple formula or how I can apply this theory in the field. You nailed it in a few minutes. Thanks. Hope you keep your prices the same, I want to get out to a class after the new year!
It all depends on how your cosine indicator works. Most angle indicators measure angle FROM HORIZONTAL, not from vertical as his picture shows. He is measuring 30 degrees, FROM VERTICAL... but your angle indicator measures FROM HORIZONTAL in most cases. At least your apps on your phone, that you can set on your barrel, etc. So, he is correct, IF YOUR ANGLE is 30 degrees FROM HORIZONTAL, his explanation and distance of 692 yds is correct. But, if your angle is 30 degrees from vertical, then it is 60 degrees from horizontal, and in that case, the (factor) is cosine 60, not cosine 30.
Just download a cosign chart for angles and multiply the cosign to the line of sight distance to target to get flat ground distance to target. That’s it. For example the cosign for 32 degrees is .8480 so a line of sight distance of 500 yards on 32 degree slope would be 500 times .8480 equals 424 yards. This works and is what the USAMU teaches in Squad Designated Marksman Training. Easy way to find angle is with a compass with built in clinometer.
The 30' angle as drawn, shows 800 yds being the H, and the vertical distance results in 696 yds. The correct angle to consider is -60' taking into account the horizon level as reference. Hence, the true horizontal distance should be 400 yds... (800 yds x Cos(60) = 400 yds). As shown in the video, you're actually calculating the horizontal distance to target, as you were aiming high up at a 30' angle.
Dear instructor If we want to Distance yards, we can use this following vertical method ...
[Height of Target (Inches)÷ Image Size(mils)] x 27.77 The horizontal method is based upon a target width of 19 inches at the shoulders. This technique can be very accurate out to ranges of 350 meters. Beyond this range it is no longer effective. Yes, we can see the height of the actual target on the ground if we are also on the ground. But how can we estimate the long range target from uphill or downhill? If we see the target from uphill, target will be shorter than actuality. In this situation, we can't rely on "target width" method. Because target is beyond 350 meters. So how can I estimate the range from mountain in mil dot?
Shooting down hill would be a negative angle (right?); 800cos(-30) = 692.8 yds, up hill, 800cos(30) = 692.8 yds: up hill or down hill your elevation adjustment is based only on the horizontal distance...
Just a quick question, why no more scope testing videos? Was it a money issue? Were manufacturers all mad? It’s an awesome thing to have quantifiable independent testing. What do you need to start doing it again.
I just aim a bit lower without holding off meat whether shooting up or down at an angle. But, I'm just a practical shooter out to 600 - 1000 yds depending on target size (e.g. Prairie Dog or man, er. I mean, Elk, etc.) and not an ELR Precision Shooter (although I know how to do it with a mil or moa optic).
I have a question: Zeroing a rifle at a range. How does this affect building your dope given that ranges have targets varying elevations? Some ranges have long distance targets on relatively flat terrain, while others have the same distances on hills
no, you are solving for the down angle which is 30°. it would be 60° if shooting from the target location to standing position in this situation, which would be the up angle. if the target were only 1° below, you would not use the cosine of 89° because that would give you 14 yards. usually when using geometry calculators the hypotenuse needs to be descend left to right to assign perspective. if the slope ascends left to right it assumes you are at the bottom looking up the incline
Good question, but no. You're taking the angle formed by the adjacent side and the hypotenuse (angle ''theta") . Your LOS, of course, is always the hypotenuse of the triangle. Shooting uphill or downhill, you will always take the cosine of angle theta
The right calculation should be considering a 60 degree angle from the horizontal reference down to target. The 30' assumption is dead wrong. This guy should shoot more often.
Is this the same thing you'd do for shooting uphill? If the target was on the hill, and the shooter where the target is, shouldn't you aim higher over the target to hit it?
The cos by dope (aka Improved riflemans rule) has been proved to be more accurate than the cos by los (aka riflemans rule), completely contrary to what you say in this video. see this article for example www.exteriorballistics.com/ebexplained/article1.html
Gravity acts over time, not distance. Acceleration due to gravity is 16 feet per second, per second. That applies to a stationary object or one in motion. The time it takes to reach the target is based on the velocity of the bullet and distance. This "air time" is when gravity affects it. A precise method of angled shooting should take into account the positive (or negative) effects of gravity on the speed of the bullet and additive (or subtractive) effect on gravity when shooting downwards (upwards) as well as and change in the density of the atmosphere. All of these affect the velocity. Is the cosine just a convenient easy way to approximate the effect? Using cosine shooting upwards or downwards should have the exact same vertical adjustment correction. It is not. See Bryan Litz "Applied Ballistics for Long-Range Shooting" page 56. Cosine is a linear function. Trajectories are parabolic.
Solid info and concise. Makes my Mildot Master much more clear in my head now. THANKS
Great video. Been looking for hours on how to find a simple formula or how I can apply this theory in the field. You nailed it in a few minutes. Thanks. Hope you keep your prices the same, I want to get out to a class after the new year!
It all depends on how your cosine indicator works. Most angle indicators measure angle FROM HORIZONTAL, not from vertical as his picture shows.
He is measuring 30 degrees, FROM VERTICAL... but your angle indicator measures FROM HORIZONTAL in most cases. At least your apps on your phone, that you can set on your barrel, etc.
So, he is correct, IF YOUR ANGLE is 30 degrees FROM HORIZONTAL, his explanation and distance of 692 yds is correct.
But, if your angle is 30 degrees from vertical, then it is 60 degrees from horizontal, and in that case, the (factor) is cosine 60, not cosine 30.
Just download a cosign chart for angles and multiply the cosign to the line of sight distance to target to get flat ground distance to target. That’s it. For example the cosign for 32 degrees is .8480 so a line of sight distance of 500 yards on 32 degree slope would be 500 times .8480 equals 424 yards. This works and is what the USAMU teaches in Squad Designated Marksman Training. Easy way to find angle is with a compass with built in clinometer.
The 30' angle as drawn, shows 800 yds being the H, and the vertical distance results in 696 yds. The correct angle to consider is -60' taking into account the horizon level as reference. Hence, the true horizontal distance should be 400 yds... (800 yds x Cos(60) = 400 yds). As shown in the video, you're actually calculating the horizontal distance to target, as you were aiming high up at a 30' angle.
yup, the angle drawing was wrong
Thank you for posting the film.
Dear instructor
If we want to Distance yards, we can use this following vertical method ...
[Height of Target (Inches)÷ Image Size(mils)] x 27.77
The horizontal method is based upon a target width of 19 inches at
the shoulders. This technique can be very accurate out to ranges of 350
meters. Beyond this range it is no longer effective.
Yes, we can see the height of the actual target on the ground if we are also on the ground. But how can we estimate the long range target from uphill or downhill? If we see the target from uphill, target will be shorter than actuality.
In this situation, we can't rely on "target width" method. Because target is beyond 350 meters. So how can I estimate the range from mountain in mil dot?
This is very good. Do you have calculations for shooting uphill at a steep angle? Is it the inverse so that at about 20% it would be 105% distance?
Shooting down hill would be a negative angle (right?); 800cos(-30) = 692.8 yds, up hill, 800cos(30) = 692.8 yds: up hill or down hill your elevation adjustment is based only on the horizontal distance...
As others have said, the FLD would be found by the SINE of the angle- 30 degrees- not the COSINE, in this case. SOH-CAH-TOA.
Great video.. really helps visualize
Just a quick question, why no more scope testing videos? Was it a money issue? Were manufacturers all mad? It’s an awesome thing to have quantifiable independent testing. What do you need to start doing it again.
I just aim a bit lower without holding off meat whether shooting up or down at an angle. But, I'm just a practical shooter out to 600 - 1000 yds depending on target size (e.g. Prairie Dog or man, er. I mean, Elk, etc.) and not an ELR Precision Shooter (although I know how to do it with a mil or moa optic).
Correct / Agree.
Always hold on hair ( or chest if man, er... elk ).
If you have to hold off hair, you're not close enough in hunting to shoot.
I have a question:
Zeroing a rifle at a range. How does this affect building your dope given that ranges have targets varying elevations? Some ranges have long distance targets on relatively flat terrain, while others have the same distances on hills
Best explanation I've seen on this.
Hey Tyler. Any idea where I can get one of the slings you designed for Ares?
wrong according to your drawing . Correct solve is 800 X cosine of 60 degree angle to horizontal, so 800 X .5 = 400 yard shot
no, you are solving for the down angle which is 30°. it would be 60° if shooting from the target location to standing position in this situation, which would be the up angle. if the target were only 1° below, you would not use the cosine of 89° because that would give you 14 yards.
usually when using geometry calculators the hypotenuse needs to be descend left to right to assign perspective. if the slope ascends left to right it assumes you are at the bottom looking up the incline
Wait,SOHCAHTOAShouldn't that be SINE?
Good question, but no. You're taking the angle formed by the adjacent side and the hypotenuse (angle ''theta") . Your LOS, of course, is always the hypotenuse of the triangle. Shooting uphill or downhill, you will always take the cosine of angle theta
The right calculation should be considering a 60 degree angle from the horizontal reference down to target. The 30' assumption is dead wrong. This guy should shoot more often.
Is this the same thing you'd do for shooting uphill? If the target was on the hill, and the shooter where the target is, shouldn't you aim higher over the target to hit it?
no , up and down are the same
The cos by dope (aka Improved riflemans rule) has been proved to be more accurate than the cos by los (aka riflemans rule), completely contrary to what you say in this video. see this article for example www.exteriorballistics.com/ebexplained/article1.html
What about shooting uphill???
Angles are angles, and gravity doesn't care.
Ie: Sameo-sameo ...
Here sin30=0.5
Damn
Here true range=800ydsXcos60=400yds
I think you messed up your drawing
Gravity acts over time, not distance. Acceleration due to gravity is 16 feet per second, per second. That applies to a stationary object or one in motion. The time it takes to reach the target is based on the velocity of the bullet and distance. This "air time" is when gravity affects it. A precise method of angled shooting should take into account the positive (or negative) effects of gravity on the speed of the bullet and additive (or subtractive) effect on gravity when shooting downwards (upwards) as well as and change in the density of the atmosphere. All of these affect the velocity. Is the cosine just a convenient easy way to approximate the effect? Using cosine shooting upwards or downwards should have the exact same vertical adjustment correction. It is not. See Bryan Litz "Applied Ballistics for Long-Range Shooting" page 56. Cosine is a linear function. Trajectories are parabolic.
nope ，i think you are wrong
i do trigonometry in math class
İt is false. No calculate with cosinus. Calculating with sinus.
Flat range distance = BS
...bad formula
awesome explanation. thanks for share your aknowledgement