Understanding How Arrows Drop - Archery Report

archeryreport.com/2011/06/understanding- arrows-drop

Uphill and Downhill Shots, How to Adjust for Proper Arrow Impact

There is often confusion when it comes to shooting uphill and downhill shots on how to adjust for the incline. Do you hold high on uphill shots or low on downhill shots? Vice versa? Or no change at all? The answer may surprise some people.

The key to understanding an arrow’s trajectory on uphill and downhill shots is realizing that gravity only acts perpendicular to the earth’s surface. Thus an arrow is only acted on by gravity for the distance that it travels parallel to the earth, or rather only the horizontal distance. This results in having to aim low for both downhill and uphill shots!

Because the actual distance to the target will always be greater than (or equal to) the horizontal distance to the target, an adjustment must be made when shooting at extreme angles so that the yardage used on the bow sight matches the horizontal distance. By remembering our geometry lessons, we can quickly calculate the amount of yardage that must be “cut” for either an uphill or downhill shot.

A right triangle is formed by the shooter’s height above the target, the actual distance to the target and the horizontal distance to the target. The Pythagorean theorem states that the sum of the squares of the sides of a right triangle is equal to the square of the hypotenuse. By knowing the height the shooter is above the target and the actual distance to the target, the horizontal or the aiming distance can be calculated.

US archery BB team had some surprises with the uphill and shot high. https://youtu.be/nEmEsf5Acvs

Shooting Arrows Uphill and Downhill Learning to shoot uphill and downhill is a must if you ever plan on hunting steep or hilly terrain. The fact is most bowhunters who are not experienced in shooting up and down invariably shoot high. Deer and other game live in a wide variety of terrain, and if you are hunting out west you will be hunting them in steep canyons and mountains. Learning how to shoot effectively in these conditions is imperative.

The illustration shows the problem you encounter when shooting uphill and downhill. In this situation, the ram is actually 30 yards in a straight line from the bowhunter, so in his mind he sees the ram at that distance. But the actual lateral distance is only about 21 yards. Gravity pulls on the arrow the same whether going up or down, at least as far as we are concerned in close range bowhunting situations, so the actual shooting distance would be closer to 20 yards, not 30 yards. The result of shooting for 30 yards would be to shoot high, either missing the ram completely or wounding it. Since the vast majority of traditional archers use instinctive shooting, the only way to learn how to shoot uphill and downhill shots is to practice them.

If you don’t have hills where you can place targets high or low, try using an elevated platform or treestand to practice. Using a couple of 3-D targets will be more realistic. Just remember to always shoot for the vitals. The more experience you have at shooting from these angles the better your chances of making a killing shot on game in the same situation.

No discussion? lol

Demmers quote post-Cortina.

"Made a good shot. Guessed wrong on the approach. This is what happens with barebow and steep angles. Everyone is different and even distances are different. I added 10% to the 20 meter shot and hit just left. I added 8% to the 50m shot and should have not added anything. I know some didn't add and hit low, I know some who didn't add and hit close. I know some added 8% and hit good, and I know some besides myself who missed high. " Demmer

Sam -

You got enough of a discussion on the other site. That went in to the "a little knowledge is a dangerous thing" category.

For most hunters, talking an uphill or downhill shot, aiming slightly lower than the line of sight distance, or as you described the ground distance will put the arrow where it needs to be. You're just not shooting at distance long enough to need a calculator to figure out.

While what you're saying is true, all it does is add a totally unnecessary complication. I do agree, that if you're going to put yourself in that kind of situation, the only logical solution is to try it and practice it.

K.I.S.S.

Viper out.

Agree, and my objective is to make people conscious of shaving off a dab to make a killing shot and save some high hits and gimped game with this knowledge.

Just the same way your diagram shows a 21yd shot looking like 30yds, I believe most guys miscalculate their actual height from the ground.

I always tell people to shoot the horizontal distance, as you have illustrated. A three yard shot from 18', is, to me, near enough in visual perspective when practicing from 3' up. Accordingly, I practice near straight down shots while standing on a picnic table. I gap shoot.

The shoulders of the deer in the photo were no more than three yards from the base of my tree. He was on the uphill side, and his body was head first angled uphill. I picked a spot behind the hump his shoulders created on his back. He was looking for me by stretching his head up and trying to see as far as he could towards the hilltop. I have no doubt he ducked/jumped the string, at the sound of my release.

My foot platform was 18' from the ground, at the tree base. I watched the deer move uphill to me. He ignored a warning, which a flock of turkeys sounded, as they spotted me and moved away. He found and followed my scent trail to the tree and stood there looking for me. When he stepped further uphill to spot me, the shot presented itself and I took it. From my first seeing him, to the release of my arrow, was about forty-five minutes.

Great stuff and what a fine Buck!

Lol, Bam defies gravity.

Well, here's my take on this. If your shooting a method that uses a physical site, you are going to have to adjust accordingly for your shot. I shoot instinctive. My first shot at a deer from a tree stand, after my conversion back to shooting Trad., I missed. My fault, did not practice elevated. So, I climbed the roof of our house and started shooting at random targets on the ground. The next two shots I took yielded a nice fat doe and an 8 point. I did not physically change anything except getting my brain to properly see the shot. I almost find it easier now shooting from an elevated level with instinctive shooting.

Uphill or downhill shots have a diminished gravitational effect on the arrow and cuts in yardage are necessary.

There's another reason folks miss high on uphill and downhill shots high. From either position, you're looking at a different part of the deer. "Center body," when viewed from above or below, is already above the center of the animal as viewed from a horizontal position.

Add the tendency for most shooters to not bend at the waist and/or lift up a little on a downward shot, and the arrow goes higher yet.

IMO, these factors have a greater effect than gravity. Regardless, practice is the (only) way to determine where to hold.

There is a difference between uphill and down. I remember two targets at ETAR. One was a 35 yd shot uphill at about a 45 deg slope ( a rope was there to help climb up to the target ). Most shots came up short. Probably only 20 yds horizontal distance but you had to aim like it was a 40 yd shot to hit it. The target was lower on the slope the following year , so must have had a few complaints. Then there was a shot after the trail had just turned down. The first shot is at a deer in a gully. The stake is about 40 yds but there is a little bench further up where we could take a clear about 60 yd shot. That one you had to shoot like it was a 30 or you would be over it. I think it's fun to practice these shots.

Honestly it's pretty much all body alignment to the grade. I've shot plenty of field rounds on sidehills, up and down hill, etc., and if you align your body/upper body to the shot, you won't have much of a problem. Side hill shots can be problematic as well if you're not paying attention or have not practiced them on a relatively steep slope. That said, at hunting distance it should be pretty much a non-issue unless you are shooting over 30'ish yards.

"Probably only 20 yds horizontal distance but you had to aim like it was a 40 yd shot to hit it."

Precisely counter to science as Sam has explained.

Sam, "Since the vast majority of traditional archers use instinctive shooting..." Do you really think that's true?

Could be why this is called 17.3 yard accuracy site.

Bowmania

If someone is interested this might be a good read for some:

https://assets.sportstg.com/assets/console/document/documents/12 15%20understanding%20fita%20field%20archery%20booklet.pdf

PS Take the space out between 12 and 15 to have a workable link

Could be Bowmania? Some guy is also saying on another forum that your arrow drops more up hill?

That guy says something else: when you shoot uphill the arrow trajectory is affected more by the gravity than the arrow trajectory of the arrow shot downhill.

I wonder about that Draven, can anyone lay some light on that claim?

For me trajectory is the same in all 3 situations (uphill, downhill or horizontal) IF I use the same bow and arrow combo and the same shooting form to launch the arrow. Is not like the arrow is an air-to-air missile that hits at 1000km.

Folks, there is a lot of physics going on with this entire discussion. And many think they have it and don't. But the answer is really only available if you look at the physics and math of the question. Many here won't like this but maybe some will understand the real science behind the discussion.

Link used in another website with the same/similar discussion.

https://www.khanacademy.org/science/...jectile-part-1

Need to watch all 4 parts to get the whole explanation.

Arne

PS. Gravity affects a projectile the EXACT same downhill, level or uphill!!

Arne

30 yards is 30 yards. Up hill, down hill around the side of a hill, it doesn't matter. Can't really understand why one would consider the distance the target is from the bottom of the tree to have any relevance on the shot at all.

fdp the human factor is always contradicting the scientific logic. Since there are physical limitations most of the time and we can't achieve the perfect T from any position and we are poor distance estimators we find arguments for the above and we pass them down as "take them in consideration" but "go out and find out by yourself" is the best way.

Arne, are you saying up and downhill cuts of yardage are all hogwash?

Would like to know your perspective.

Up and downhill angles change the horizontal distances.

Most would say to shoo the shot based on the horizontal distance.

The H distance is always less, usually.

Gravity effects a projectile only over the distance that it travels horizontally, which is always less than the distance from elevation or declination, which is what your eye sees and your brain wants to perceive as actual shot distance. If you proceed on that true but misinterpreted information, which is actually the best example of the current buzz phrase on this site "Fake News" then you will shoot high because you are perceiving a longer shot distance than the one that gravity actually acts upon. There is a solution to this and it requires math, understanding and applied intelligent practice. No Zen, Force, Mojo or "Bareing Down" is going to resolve this for you, which is why they call it Poke & Hope and Grip it & Rip It. Just as well buy a Lottery ticket.

Yep, and while some claim it that there is no difference, they do so mostly because they not actually been in the field and shot the shots enough to understand it.

They simply do not have the practical experience.

I agree with the gravitational pull being equal. When I hunt in a stand I range the distance to a tree at my level....then I know a deer at or near that tree base is my predicted horizontal distance.

"Gravity effects a projectile only over the distance that it travels horizontally, which is always less than the distance from elevation or declination,"

You might want to reformulate or the arrow will be lost in space when you shoot uphill.

Gravity is time dependent. An arrow slows faster going up than down. So as it takes longer to get to the target the more time gravity has to work on the arrow and the more it will drop. The effect is more noticeable with increasing distances.

Sam -

Ya know, this is a prime example where the "Internet" does more harm than good. A lot of theories posted by people with little to no practical experience.

How's this for an idea, assuming you have a formal and reliable aiming system set your "sights" at a 15 to 20 yard target, then climb a tree 15 - 20 feet and use the same "sight". See where the arrows go.

Kinda ends the debate.

Viper out.

Viper, at known and verified 20 yards between me and target until the form is altered my gap is the same in all 3 situations. BUT I have to compensate for the difference between broadside gap arrow position and downward/upward gap arrow position. If the belly line is where I hold the arrow in broadside situation when I am way up above I need to hold the arrow under the belly line to get the same gap. Understanding distance and the difference between what you know and what you think you know is way more important than the action of gravity on the arrow path at 20 yards.

How we think before shooting:

How we are actually compensating for the correct shooting:

: Viper Private Reply Date: 21-Sep-18

Sam - Ya know, this is a prime example where the "Internet" does more harm than good. A lot of theories posted by people with little to no practical experience.

How's this for an idea, assuming you have a formal and reliable aiming system set your "sights" at a 15 to 20 yard target, then climb a tree 15 - 20 feet and use the same "sight". See where the arrows go.

Kinda ends the debate.

Viper out.

Sounds good to me..

You know you can buy a rangefinder now that calculates the cuts for you.

quote

Here's the numbers I have memorized for uphill/dowhill shooting in case you don't have access to a angle compensating rangefinder but can measure angle.

Percent of distance to cut, 5 degree increments from 10 degrees to 45 degrees. 2%, 5%, 7%, 11%, 16%, 20%, 25%, 30% Just in case you ever need them. 10*, 15*, 20*, 25*, 30*, 35*, 40*, 45* (* = degrees).

These are for downhill shots - I typically use 2% less for uphill, so for 10 degrees uphill, 2% minus 2% for uphill = no cut, similarly 30 degrees uphill = 16% - 2% = 14% cut.

More examples... so if you're 60 yards away at 22 degrees downhill, call it a 10% cut, 10% of 60 = 6, so cut 6 yards and shoot it for 54. Another example... You're at 70 yards with a 20 degree uphill shot (7% is the number, subtract 2% for uphill, so you get 5% cut) 5% of 70 is 3.5 yards, shoot it for 66.5 yards. Takes some mental gymnastics, but has served me extremely well hunting and in competition.

You know Golfers and rifle shooters have known about the slopes and compensating for the angle for years and you can buy rangefinders for bowhunters too. You need to know the horizontal distance and compensate for the slope or angle to make a good shot. The angle changes everything unless you know your exact trajectory on angles for each shot.

https://www.archersadvantage.com/Tip...UpDownHill.htm

This has been very interesting, although with the measurements used in the original illustration not particularly useful to bowhunters, (sorry Sam) and that is probably why there is so much confusion.

And the example of the Demmer quote i isn’t helpful, because it clearly shows that quite a number of those folks missed the shot. And they were all using different “formulas”. Although we know that one of the shots was 50 meters, and another was 20 meters, we don’t know the elevation change from the shooting stake to the target, so we don’t know the angle. “Steep” is a relative term. It’s not likely the angle from the shooting stake to the target was more than 20 degrees. Could have been, but not likely. Was the 50 meter measurement line of sight, or measured on the ground? If the measurement is line of sight, (50 meters) and the target was 5 meters higher than the shooting stake, that would have made the angle (between our line of sight, and the target to be hit) 5.74 degrees. Meaning that the shot should have been taken as if it were 49.5 meters away. Explaining why his shot was high. He stated he added 8% to the range. The shot was nade as if the target was 54'ish meters away.

In the example of the elevated hunter the illustration shows a 60' elevation change (hunter is 20 YARDS above the deer) over the course 63' (21 YARDS) of travel. That isn't realistic for most folks. One would have to be shooting off a cliff essentially to get in a situation like that. Not many bowhunters are going to climb 60' up a tree, or be in a position even on the side of a hill where they are going to be 60' above their intended target.

A much more realistic scenario would be for side A of the triangle to be between 5 and 6 yards (15-18 feet). I'd say that's about average for most tree stand hunters (which I would think is as much what this was geared to as anything else). In that situation, the angle formed by the line of sight, and the actual spot on the deer to be hit would actually only be 16.7 degrees as opposed to the angle in the example which is more like 44 degrees. That makes a HUGE difference in the calculation of the shot.

These shots are based on the angle formed by our line of sight, and the target to be hit. The greater the angle, the more allowance that has to be made for yardage. The lower the angle, the less effect it has.

Using the example of being 18 feet above the target. with the same 21yard (63 feet) walking distance from the animal to the base of the tree/elevated stand, that would make the angle of the shot more like 16 degrees. At 16 degrees, the actual ballistic path would be more like 85.5 ft. (28.5 yards) as opposed which is 1.5 yards less than the 30 yards shown as the line of sight. I don’t know very many people who can calculate range that effectively with the naked eye (I sure can’t do it consistently) and. With most modern archery equipment, when holding center of mass on something the size of a deer’s vitals, (just use 9” in diameter as an example for that measurement) that isn’t going to make any practical difference in a hunting situation, at typical bow ranges.

There is such a thing as over complicating these types of situations, and using anecdotes and analogies that don’t really apply.

Hedge Hunter,

"One only needs to look at the above deer and arrow angle to see if you put it on center body yer gettin no vital."

If you are referring to the photo I posted, you are wrong. The heart photo to the side of the deer, was the deer heart, clearly a "vital".

Sam,

I believe the golfer illustration is misleading, that is, had the ball been on a trajectory for 150yds., it should have gone beyond the pin/hole. I've included a red line on the actual level of the golfer and you can see that the red line marked "actual distance", is a hypotenuse, therefore longer than the actual horizontal distance. Both ball trajectories are speculation on the part of the illustrator, and intended to lead observers to accept the premise. To illustrate my point of illustrator license, I've copied the distanced from the flag to the horizontal and laid it to the right of the vertical to the flag, which clearly demonstrates it falls short of the illustrators allowance for the height of the pin above horizontal from the golfer.

Clear back in 1999, Archery Advantage had this article on this subject. Of course they also had a "fix" for solving the problem for sale, but the illustrations and text are interesting. They explain much better the launch angle, arrow speed differences, etc.. If you are really interested in the subject it's a good read.

https://www.archersadvantage.com/TipSheets/UpDownHill.htm

FDP quote;This has been very interesting, although with the measurements used in the original illustration not particularly useful to bowhunters, (sorry Sam) and that is probably why there is so much confusion."

How about you write a letter to the editor of Traditional Bowhunter Magazine and let them know that Frank?

TJ Conrads did that drawing at the beginning of the thread and I am willing to bet that TJ has forgot more about bowhunting than you or me Frank? lol

TJ is the owner editor of TBM.

Yes pdp...this is TJ's illustration so you can copy it and send it in with your letter to TBM and tell them it is "This has been very interesting, although with the measurements used in the original illustration not particularly useful to bowhunters, (sorry Sam) and that is probably why there is so much confusion."

Just not gonna work for bowhunters.. PS, please let us know what TJ tells you?

Sam,

I hadn't noticed before, but now that you mention that diagram, the 30yds in the top half is just as long as the 21yds in the bottom half. Also, in the bottom half, I suspect the elevation of the hunter is intended to read 20', not yards, but in any event, the scale is not exact, and as I said before, intended to "lead the observer to accept the premise".

I think it still applies accurately. Trust TJ 100%

You think or you know it because you tried it? I've shot today for the hell of it with my Chekmate from the 6m tree stand to a deer target at 32m direct distance. My normal gap at 30m with the bow and arrow (#76@28" and 663gr arrow) is a tad above the line of the belly. I had to shoot above the x to make it to the 10 ring because the 660 gr arrow drops quicker, no matter if the theory says with more speed.

PS The same deer from same position and using my ILF rig #52@28" and 450gr arrow I use the same gap as for 30m and it works like a charm.

I have tried it many times

1995, Ophir Pass Colorado.

At 11000 feet altitude

Elk season archery. Witness K Hillhouse

Equipment; Quilliam Patriot recurve, 61@28 Arrow; 2216, 29 inches and a 125 NAP Thunderhead BH.

Three Elk came below me at 20 yards and could not shoot because of movement to get a shot. Extreme angle down from me as they passed below me. I waited for them to move quartering away and the angle still 40 degrees or more below me as they moved to my right.

When the three Cows came into an opening at 35 yards, I let the first one pass, the second pass (calf) and the third cow paused in the shooting lane. I aimed for 20 yds. and she was was 35 downhill. the arrow hit her in the last rib right side and angled forward into the vitals. 50 yd. trail job and she was down.

This has played out numerous times on Mule deer and WT deer in my hunting years between 1988 and now. I shoot the shot on angles downward out to 20 yds. and have killed 54 WT deer with trad gear. I have killed several from 20 feet up or more almost under me and always aim the shot for point blank on these.

Have killed many out to 20 yds at 40 degree plus angles and always aim lower on the animal and it drops in the kill zone for meat.

I used to shoot 3D all the time and from 1988 to 1993 used 80 pound High Country Compounds shooting as a sponsored shooter. I always cut yardage for angles and always had it work that way. I have not shot Compounds hunting since 1995.

Angles are real no matter if you shoot C Bows or Trad, 300 win mag rifles or muzzleloaders.

Sam...I know who TJ is. Next time I run in to him around a show somewhere I will mention it to him if the subject comes up, or I think about it. He's only a man.

Hedgehunter, the answer for you is probably a rangefinder. The answer for me is if I had a bow as slow as you describe, I'd burn it.

TJ is a great Bowhunter and knows from experience what works and has written several Books on Bowhunting. Maybe you can straighten him out Frank? lol

Sam...there's no reason for to become a horse rear again like you did on the Ploen thread simply because not everybody agree's with you. TJ probably didn't even do the diagram. He did the writing, and then an illustrator did the diagram most likely.

You never provided a shooting solution to the equation diagram any way. At least I didn't see it, so posting it was more or less pointless. I went to the trouble to actually READ what the diagram said, and it is a poor representation. You should know that as much time as you have spent bow hunting.

And, as was mentioned previuosly, the height of the hunter was probably supposed to be 20". If that was case, then the whole diagram is out of proportion as the angle would be much less.

Sam, angles are real and human factor IS REAL TOO. Way more important when you shoot stick and string than shooting a firearm. Question, you are talking about aiming low and how the hunter should think. But how about the anatomy? From what I've seen, once you are above a certain angle - around 30 - you should start to aim higher to get the both lungs. Right or wrong?

Agree that there are Human inputs. Will not post any further in this thread because I see the attempt to get it closed from FDP's last post. Again, please do not close this very informative thread and I will not post any further. I hope others will keep the thread going with input and vehemently disagree with fdp s attempt to get it shut down by going the low road and calling me names. Please disregard it Mods,,sticks and stones,,thank you Sam out.

Draven,

If the game was broadside, maybe. That is better determined once you see the angle of the game relative to where it is standing, and that may be uneven footing for the game, such as stepping into a hole or climbing up. If the game is quartering away, you may not get both lungs.

You must pick a spot on the game where you either aim for both lungs or the heart, and to hit that spot, shooting the horizontal distance gets it there.

Sam...I'm not attempting to get anything closed at all. Anyone who wants to can disagree with me. As I said in the PM response, I don't NEED anyone's approval for the opinions and experiences that I post. If you don't want someone to call you out, then don't do the passive/aggressive stuff that you do, simple as that.

You had said previously that debate made for a better exchange of information (at least that's what you said about the other thread) well, this is another one I'll debate because the diagram is still a poor representation.

Thanks Wild Bill

Can you make this shot? How far away from you is this deer?

5 yards

I cant the bow more down hill and hold it straighter up for long shots and uphill, visually it works out the a lot of the differences. Charting such things makes sense for sight shooter that never vary the cant of their bows, but in the a pressured hunting situation, probably over the top. .

FDP, I explained in another post that the 20 and 50m shots were almost identical on the angle. 20m shot was approximately 28° and the 50m shot was 31°. This was confirmed by my rangefinder after the shoot was over. 20m I shot for 22m because I know what it does at that angle by experience and not any sort of physics. I never shot that angle past 25m, so 50m was a wild guess. Since I added 10% to 20m I figured I'd play it safe and just add 4m figuring I'd I'm two off, I'll still be fairly safe. For an FYI, some shot it for 50 and completely came up short and missed the target. Some shot it for 53-4 and hit it well while some missed it. Others shot it for 50 and hit it well. Angles can be all be debated on what to do, but it comes down to personal styles and 100a% experience. Ask ten people what they do for those angles ups and downs, and you will probably get 10 different correct answers.

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