shot angle

[Chad]

when shooting at extreme angle either up or down dose it affect the trajectory of the arrow at all? say a 30 meter shot on flat ground as apposed to a 30m shot up hill or down hill. Will the arrow hit the same spot no matter what angle, or will it shoot high or low?

[Luke]

Hey Chad,
the angle will affect your arrow flight as it's the horizontal distance traveled that makes the difference in arrow drop.

The less horizontal distance the less "high" on the spot you have to aim.

At least, that makes sense to me ;)

Someone please correct me if I'm wrong :rolleyes:

Luke

(Leeroy's bro in law ;).. Chad know's who I'm talking about :P)

[hunt or be hunted]

hey mate if your shooting up or down hill at say 30m use your 20m pin and same with other distances, if shooting at 20m use your 10m pin.

someone else shold be able to give you some better more technical information.

dan.

[Wareagle]

hey mate if your shooting up or down hill at say 30m use your 20m pin and same with other distances, if shooting at 20m use your 10m pin.
dan.
I would rethink that, it would depend on the angle.:)
I found what worked for me in 3D(when I could shoot OK) shooting up or down hills, regardless of the angle. ie:- a target 40m down a steep slope etc.(as viewed with a range finder)now imagine a vertical line (plumb bob) coming up level to you. now the distance to that point( depending on the slope) was 25m. That's the distance I would shoot it at, and nail the sucker.
It's not 100% but close enough. the same with up hill, hope that helps.

[hunt or be hunted]

I would rethink that, it would depend on the angle.:)
I found what worked for me in 3D(when I could shoot OK) shooting up or down hills, regardless of the angle. ie:- a target 40m down a steep slope etc.(as viewed with a range finder)now imagine a vertical line (plumb bob) coming up level to you. now the distance to that point( depending on the slope) was 25m. That's the distance I would shoot it at, and nail the sucker.
It's not 100% but close enough. the same with up hill, hope that helps.

its what works for me mate. but your idea also makes sence so there must be multiple ways?

dan.

[sparra_gump]

I wouldnt say mulitple ways the laws of physics are what they are, i would say different factors would give a different result across the board.

Forces such as physics are directional which means when shooting on flat ground the gravity is pushing the arrows down 90 degrees to the arrow where as shooting up hill gravity pulls on the arrow in a different direction in relation to the arrows movement (still downwards towards the ground but the arrow direction has changed).

Back in the day i could have calculated the changes the would accour but sadly i no longer has a physics mind.


SG.

[Wareagle]

Hmmm.... My High School days at Quirindi..good memories:)

[sparra_gump]

You went to Qdi high??? i though i was in the very small minority that had been there.

[troy]

Easy way to remeber is "Up- high, Down- low". Translation if you are shooting in uphill aim slightly higher; if you are shooting downhill aim slightly lower. Without being too scientific (mainly because I'm not), when you sight in or practice shoting you compensate for the force of gravity, wanting to pulling the arrow down, on a level plain. Adversly when you increase or decrease the angle at which you are standing/aiming to take your shot the compensation factor that you have become acustomed to or sighted your bow to changes. Shooting downhill the gravitational force, though still the same, has less effect on the arrow hence a 20yard distance will only require aiming at what normally is 10-15 yards. And the reverse for an uphill shot.
As a point of interest some of the new range finders actually have a built in compensation device that allows for the angle at which you take your reading giving what the manufacturers have dubed "True Distance" readings.

[Wareagle]

You went to Qdi high??? i though i was in the very small minority that had been there.
Yep, my father was the manager of the mission station at Caroona.( probably the last) The school teacher now lives in our house.( I think)
Sorry for getting off topic.:)

[Wareagle]

Easy way to remeber is "Up- high, Down- low". Translation if you are shooting in uphill aim slightly higher; if you are shooting downhill aim slightly lower. Without being too scientific (mainly because I'm not), when you sight in or practice shoting you compensate for the force of gravity, wanting to pulling the arrow down, on a level plain. Adversly when you increase or decrease the angle at which you are standing/aiming to take your shot the compensation factor that you have become acustomed to or sighted your bow to changes. Shooting downhill the gravitational force, though still the same, has less effect on the arrow hence a 20yard distance will only require aiming at what normally is 10-15 yards. And the reverse for an uphill shot.
As a point of interest some of the new range finders actually have a built in compensation device that allows for the angle at which you take your reading giving what the manufacturers have dubed "True Distance" readings.
I never found that works for me, if I put more distance on a up hill shot, I'd go over its back. The way I see it, down hill, gravity pulls from the point end. up hill from the nock end, still less area for gravity to pull on... interesting subject.

[Luke]

Where's Jeremy with his fantastic physics freaky fascination when you need him ;)

:P

[rudy]

A lot depends on what the angle your shooting on. You may think you have to take 5 or 10 metres off shooting down hill but in fact sometimes its only 1 or 2 metres. I base this on using my range finder, before i start to whisle for foxes i range the base of a tree down the hill, say its 23 metres then if can i will range the top of the tree on my level and it will be only a few metres shorter. You have to get into some pretty steep country where you're taking off more than 10 metres.
Just my opinion.

[Antarcher]

I have always thought that you held low for up and down hill shots. Still you need a pretty steep angle before it takes effect and a fair distance also. I think the best way to find out for yourself is to get out and practice at different angles and see how much higher or lower you hit at different distances and angles.

Also each bow shoots different and no two hunting scenarios are the same. I think you will be surprised at how steep an angle you need to be shooting on before there is any significant change in your impact point.

[ozzyshane]

Ant u r wright u aim low with both up hill and down but u are very wrong about needing a lot of angle to make a diff a lot will depend on how fast your arrows are going and distance and angle.

My red deer was 51m but with the angle i had to aim at 44m most of our goat country u will have about 8% to 10% to take of for a lot of up and down hill shots.

If u do a search there is a chart on the net about this or just by a tilt angle rangefinder like i have .

Hope this cleared it up Thanks Shane

[Antarcher]

Fair enough Shane. I have looked at the charts you speak of at Peg's and found that with my set up at the time that i didn't have to worry too much until I got out past 45m. Be good to get the link up for it, but i have no idea where it is.

[Sagitarius]

It's a bit tricky, some more background on the subject might be needed.

Firstly max range is at at 45 degrees, so there are two elevation angles that will land on the same target over flat ground.

Secondly if your shooting at a (obtuse) target at an angle with more than 45 degrees of elevation (up or down) then you need to start doing the inverse of what you do with a (acute) target at an angle with less than 45 degrees of elevation (up or down).

If your with me so far this is from wiki [ http://en.wikipedia.org/wiki/Trajectory_of_a_projectile#Angle_.CE.B8_required_t o_hit_coordinate_.28x.2Cy.29 ]

To hit a target at range x and altitude y when fired from (0,0) and with initial velocity v the required angle(s) of launch θ are:

http://upload.wikimedia.org/math/9/8/9/989f9cb1987b7736e916f87b8d9b2806.png

Each root of the equation corresponds to the two possible launch angles so long as both roots aren't imaginary, in which case the initial velocity is not great enough to reach the point (x,y) you have selected. The greatest feature of this formula is that it allows you to find the angle of launch needed without the restriction of y = 0.

[Luke]

Note to self - add graphical calculator to list of essential hunting items :P

[Sagitarius]

Could just get a rangfinder with arc if you want a bit of gear to do it.

[Antarcher]

We need a site feature that has a calculator and spell check while we are at it

[Jeremy87]

Where's Jeremy with his fantastic physics freaky fascination when you need him ;)

:P

I've got nothing on this one. and i was going to start up on my assignments today and now i have to find out otherwise it will bug me.

[Wellsy]

(sorry about the quality of the drawing)
http://img.photobucket.com/albums/v713/wellsyinoz/CCF15042008_00000.jpg

This is the way I get around it.
Just think of a right angle triangle with the hypotenus being the actual distance, but your aiming distance should be the baseline. Probably not 100% but i find it's pretty close.
As Warlock said if downhill try and find a tree close to the target and estimate the distance horizontally to its branches rather then the ground distance to its base.
Hope you can understand what I'm saying

Wellsy

[Luke]

the angle will affect your arrow flight as it's the horizontal distance traveled that makes the difference in arrow drop.

The less horizontal distance the less "high" on the spot you have to aim.

Just think of a right angle triangle with the hypotenus being the actual distance, but your aiming distance should be the baseline. Probably not 100% but i find it's pretty close.

I guess there are many ways of saying the same thing ;)

:P

[Wareagle]

Check this out. www.ArcherRange.com (http://www.archerrange.com/)

[Sagitarius]

I wouldn't waste the money, have a look at how you use it with hills.

http://www.archerrange.com/HillMethods.htm