Shooting downhill?

With archery gear where a few yards can be critical,the difference due to the angle could very well be a factor.In this situation,using a high powdered rifle at 150 yards with a 30 degree angle it isn't wourth considering.However if you are hunting sheep or goats in the mountains,the difference in actual distance due to the steep angles can be the difference between a clean kill or a miss at longer distances.
 
Sharkson said:
YOU ARE CORRECT SIR.

I had the same discussion with folks in my hunting class. My instructor was of the old school and quoted the "myth" as fact.


thank you very much...I have run into this argument many times....people still follow the theory that the shot is longer....

I have always been unable to inform them that they are wrong...It seems they can't get it into their head that gravity affects all objects regardless of their speed/angle.....

my hats off to you for being able to explain it without a link.....for me it seems people still have trouble undertstanding it even after reading it and actually puniching numbers....like you just saw with the fellow I corrected:D
 
grouseman said:
actually I couldn tell you didn't do the math before you even stated you didn't do the math...the golden rule for shooting uphill/downhill is your shot will always impact HIGH......most people follow your way of thinking( the wrong way) because of the hypotenuse(SP?) of the triangel...but however it is wrong......

so infact a 150 yrd shot would equate to a distance LESS than 150 yrds:D

That of course is absolutely correct, forgive my moment of agedness :rolleyes:
 
Its just pythagareans theory.

C^2=A^2+B^2

You are solving for "C^2" so just plug in what A and B are and find the square root of that nubmer, and you now have the ACTUAL distance you will be shooting.


There are other factors that effect the bullets path, but i do not feel like explaining them :D

The bullet will hit high if you use your "normal" scope settings. so you have to compensate by hold-under.
 
Sharkson said:
YOU ARE CORRECT SIR.

I had the same discussion with folks in my hunting class. My instructor was of the old school and quoted the "myth" as fact.

I'm both an engineer by training and stubborn :D , so I couldn't leave it alone. After wading through a whole bunch of articles and explanations, the bottom line was exactly what you said: you will always shoot higher on an angle, whether uphill or downhill.

The new fangled range finders which take into account angle will thus always show a shorter angle adjusted distance than the straightline distance. So, always aim a little LOW though as others have said, at 150 yards, it won't make much difference!

Submitted humorously- Poster seen in an office I recently visited "There comes a time in the history of every project to shoot the engineers and carry on with same" :D Seriously though, think of this in a realistic manner. Without the aid of a shooting rest and imagining a "real" hunting situation, is one's rifle accurate enough and can you match that level of accuracy to make a difference. Aim, and shoot.
 
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So from all stated above, holding low at about 1 inch or so on the animal should suffice at any given distance?

Within the 150 yards and 30 degree angle given in this example,you don't need to even hold low to allow for the angle..
Given more angle and longer distances holding 1" low could result in a clean miss.
 
Cletus said:
So from all stated above, holding low at about 1 inch or so on the animal should suffice at any given distance?

If you can aim precisely 1" low on a game animal from the kind of shooting position you might encounter in the field then you might want to go a little further into the mathmatics of it :eek:

For the rest of us...hold dead on :D out to couple hundert :p
 
A lot of misconception about shooting up or down hill has come about because of the angle of the wound channel and point of aim on the body in regard to the vitals.
For example when you are hunting out of a treestand and shooting down at a steep angle you must imagine the vitals three dimensionally and aim accordingly.
If you are at a steep enough angle shooting down and you aim at the deers side like you would on a level shot you are going to make a grazing shot. Your projectile would need to enter higher on the body to make the bullet or arrow strike the lungs and heart in the center.
Conversely if you are shooting upwards at a steep angly you would need to strike the animal much lower to pass through the center of the vitals.

Everybody confused yet!!!!:eek:

Jeezus Ricky your makin my brain hurt.:)
 
Maybe this will help...maybe not. This also shows what BIGREDD is talking about . You can see, the two bullets will have different paths through the deer even though the entry point is the same. Now this drawing is not perfect but should help.

You can also see the "Hoizontal Distance" which is 147yrds, is not much of a difference of the 150yrd Line of Sight.

deer.jpg


Different aim point on deer, due to angle to animal not distance.

deer2-1.jpg


Hope this helps to muddy the minds some more :runaway:
 
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My post from an Airgun hunting forum:

"If you zero POI (point of impact) on level ground at the base of a tree 35 yards away, them aim up that tree on a 45 deg. angle, your shooting distance will be (some trigonomerty using properties of a right triangel & Pyathagorean therum) a^2 + b^2 = c^2 ; 35^2 + 35^2 = sqrt 2450, or 49.5 yards. So your actual shot will be over a distance of 49.5 yards. But the vector for gravity is still only 35 yards (Gravity vector only applies over the distance across the x-axis @ -9.8 m/s^2) and the B. C. (ballistic coefficient) applies for the full 49.5 yards.... so you now have a very-mixed-up formula and need Newtons laws and the ability to understand "Magnitude of Vectors" to figure it all out. "Not fun", you say and you no longer want to play. Most would say that... but I am weird, and so I will STOP here.

Shots up and shots down BOTH require a hold-under as compared to where the NORMAL shot (level ground) would have POI for that same distance. You need to first know the actual distance as illustarted in the above example, then apply you normal POI, then apply the hold-under in it's non-linear, ugly formula. (In the field you will simply estimate)

Good news: There are ballistic programs "free" on the web for you to use that do all this for you. You do need to know what information is important in the formula because most all software programs have DEFAULT values you may not want to use. If you settle for that DEFAULT value, your POI will be wrong. Learn how to use the program interface, put in the proper values and the rest is magic. Try Chairgun."

hope that helped some.
 
Thanks fellas. That is what was precisely illustrated to me tonight by another person. The angle changes when aiming to "center of mass" type thing, and it is alot clearer now. Oh and by the way Kenco, your second illustration of the deer should read "UNHAPPY DEER".
 
You can't use Pythagorus(sp) in this kind of problem because you only know the slope distance to the target and the angle. You could use Pythagorus if the vertical distance was known.

To calculate the horizontal distance you have to use trigonometric functions - in this case the cosine function.

It would look like this:

COS(angle) = horizontal distance(side opposite)/hypotenuse(slope distance)

COS(angle) X Hypotenuse = Horiz dist

For a 150 yd slope dist, the horizontal dist at angles of 10, 20 30, 40 degrees would be:

147 yds COS(10) X 150
141 yds COS(20) X 150
130 yds COS(30) X 150
115 yds COS(40) X 150


So for shots up or down-hill, you have to consider the angle, especially when the shot is steep.
 
Mauser98,

You get the same results using both methods. You are estimating all variables anyway. Unless your out there with a protractor, the guess of an angle is probably as accurate as guessing your vertical distance with the deer. I would even bet more hunters are used to guessing distance then angle. (Though most hunters would exaggerate on distance estimates :eek: )

Using Pythagoras formula is just more quick and easy(some can do in their head) then digging out your calculator and trying to remember trig functions. :runaway:


Oh Cletus, I've updated the drawing for ya :dancingbanana:
 
Kenco..
could you skew the oval shape of the deer body to lean forward another 45 degrees,just so the body part,s look a little more natural...
im sure all will see a big difference in the angle of the shot then..
the reason i askfor this..
during our hunt this fall..a bear was fired upon..
the bear was facing us...we were up on a steep hill,i,d guess about 45 degree,s..the shot was aimed for the front of the chest..
just for kicks and giggles what would be the bullet path be..?
i would guess it wouldve been about a 125 yard shot..
 
BIGREDD said:
A lot of misconception about shooting up or down hill has come about because of the angle of the wound channel and point of aim on the body in regard to the vitals.
For example when you are hunting out of a treestand and shooting down at a steep angle you must imagine the vitals three dimensionally and aim accordingly.
If you are at a steep enough angle shooting down and you aim at the deers side like you would on a level shot you are going to make a grazing shot. Your projectile would need to enter higher on the body to make the bullet or arrow strike the lungs and heart in the center.
Conversely if you are shooting upwards at a steep angly you would need to strike the animal much lower to pass through the center of the vitals.

Excellent point Bigredd!
 
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