How much the arrow drops over 10,20,30, or 40 yards is a subject with lots of different veiwpoints. I have discussed it in the back yard and just recently at another site. Most people can't believe that the arrow will drop so fast.
For this conversation we will ignor atmospheric influence on the arrow that both slows the arrow speed and lowers the amount of drop. It's kind of a tradeoff that won't have a major effect at short distances. Also, we will use 170 fps for the arrow.
The formula for earth's acceleration of gravity for someone who isn't familiar is 32fps x the time (of flight) squared. Using this formula and ignoring minor atmospheric influence at short distance the results would be: At 10 yards about 1 foot of drop, at 20 yard about 4 feet, at 30 yards about 9 feet, and at 40 yards about 16 feet.
Anyone agree or disagree with that? I'd love to hear some conversation on this. Some guys will never believe their arrows are dropping this much.
:knothead: :archer2:
thats a lota drop! hmmmm,,,..il have to watch closer to see if i can see it. :saywhat:
That sounds reasonable to me.
I suspect that most archers don't realize how far above horizontal they are launching their arrow, even at short ranges.
Guy
Sounds about right to me. I believe it.
I always get a kick out the compound guys that say they can use one pin out to 40 yards. Bull! You can't beat the force of gravity no matter how fast your going.
wow that is a lot of drop, something i never really have totally thought about!
If your point on is 40 yards, then 20 yards should be the high point of the arc. Shoot the 20 yarder as is if it was 40 yards and you will not hit 8 feet above the target.
Don't believe the 16 ft drop is correct.
Believe the following equation may be more reflective:
distance drop in feet = ((time x time) x 32.2)) / 2
I'm a gap shooter. My gaps are as follows...
20 yards....point on
30 yards....plus 15"
40 yards....plus 36"
This is with an arrow traveling around 180 fps.
I entered the following data into a ballistic calculator...550gr, 170fps, max range 50yd
it came up with
10yd... 6.3" low............... 6"
20yd... 24.14" low............. 2'
30yd... 53.02" low............. 4.5'
40yd... 92.45" low............. 7.5'
50yd... 141.98" low............ 12'
I believe you, im just content that my arrows hit where i look, most of the time.....
:archer2:
Using your numbers... if I fired an arrow from my bow perfectly level with the ground and at 5 feet above the ground then the arrow would hit the ground at about 25 yards... :D
Mine don't drop 9 feet at 30yds, thats alot of drop 2fletch.
Giff, that seems closer to my experience.
This is probably why I struggle with shooting high at really close distances - it's hard to get shooting at such a low position ingrained.
We did a similar test a different way a couple of years ago. i wanted to give a friend of mine a bow built by Balenger that was different than his current bows, more reverse in the handle with a multi-radiused laminated handle, 68" i believe it's 51 pounds at 28". My son was home and in peak form. i told him too help me check out the bow to see if he thought it would a good one for Mickey. At twenty yards he was stacking tighter groups with cedar tapered shafts than thought was possible and he was tearing them up pretty bad so i told him to back up. That put him into the neighbors yard, shooting under the horizontal of my 6' 3" clothesline bar. he was getting plenty of clearance, he backed up further and was getting about 6 to 8 inches of clearance under the bar. I got an idea for him to test other arrows. We tried 1818s and 1918 with 145 grain points, which were noticeably heavier than the cedars. The difference of clearance was almost no different. I expected that he would either hit or have to shoot over, but no, a couple of inches closer was all I could see. Personally I would need to break out my FITA target bow to shoot that consistently, but all we were really trying to decide as to which arrows I should give along with the bow. The very little difference in arc was discovered as accidental observation. Now this is an exceptional bow, I often wonder if this same scenario is always just a product of initial speed or if this varies from bow to bow because of design or limb mass.
I could be wrong but I think your numbers are off a wee bit! I kind'a gap/gun barrel/point and shoot. At 30 yards I hold right on a 3-D deers back and put it in the kill. No way my arrow is arching and dropping 9'. Now if the arch and total drop was 1/2 that.......I might believe that!
Don my friend, the quiver bussiness must be slow. You have way too much time on your hands. LOL. All I know is with a T-10 parachute fully open, your traveling 13 fps when you plow in. Good luck buddy. DB
Friend, that's the second time I've seen that formula. Are you "redneck engineer" on another site? I haven't seen it before then. I lived near Madisonville (Providence and Earlington) so I know the gravity is about the same as here in NC.
Batman, I just got a break from quivers. Had three dealers order this week. Now I'm working on some great stuff for this month. You are right about the T-10 parachute. A desent of 13 fps is to fast when you're landing in a frozen suger beet field. Good luck at the IBO. You guys looked pretty good last year.
20 yrds- 7"low- bottom of deers chest
25 yrds- point on
30 yrds- 7" high- top of deer back
That calculation is not correct. Basically you could think of it like this: if an arrow was shot perfectly horizontally at the same time another equivalent arrow was dropped from the same height, they would hit the ground at the exact same time...in a vacuum so no wind resistance. so the forward velocity is independent of the gravitational pull. To calculate arrow drop at 20 yds, you would just need the time it took it to get there and plug it into a basic equation, which is what that ballistic calculator did. Unfortunately it has been 20 years since I worked with these equations in college physics so I can only recall them in a fuzzy way without looking them up. I recall videos showing in a vacuum dropping a ball and another with forward movement hitting the ground at the same time.
2fletch - Don't participate on any other site, however I am a retired senior engineer from the Aircraft Engine world.
I pulled the equation from an internet search for calculating an object's drop based on time and the accelertion due to gravity. Did see the ballistic calcs but went with the simple equation.
You could be right. I might be a redneck.
The arrow is not going 170fps all the way there it slows down pretty fast. Pretty neat stuff any way. As long as they hit where I want them to.Or close to it. :rolleyes:
That's why it is hard to shoot through a hole in the brush that is 15 yards away.. Most people will hit something on the top of the window..
Ever try shooting at something through a 3 wire fence? How many times did you hit the upper wire?
i have one sad tale about trajectory. i was woking my way on the edge of flat corn field with a 25 yard brushy edge to the fence. The 12 point massive dominant buck was coming up the hill towards the fence nearing the top flat. Looking at the situation, I decided that I needed to clear that top wire by 1" to 3" for the arrow to drop into the spot. When the time was right i drew my 90 Hill bow back and cleared that fence by 2" and sailed that arrow 7" over the bucks back and 300 yards down the open wooded hillside into a sampling. I bend down a bit when I shoot. If I would not have been doing all of that math, I would have shot between the two top strands and killed the buck.
The laws of Physics have not changed for a very long time. Trajectory was a known quantity way back in the roman era and before. It is interesting to learn what trajectory is or will be. It is another thing entirely to try and apply those facts to how we shoot. I focus on staring at what I want to hit and then hitting it on the first shot. I love understanding how it works, I am not capable of actually applying it mentally to the already complex physical and mental process of shooting a bow.
No disrespect intended, but there is no way an arrow drops 9' in 30 yds. There must be an error in the formula. Imagine if you are shooting at an indoor range.If your arrow leaves the bow at 4.5 feet above the ground. The ceiling of the range would have to be at least 13.5 feet tall or the arrow would hit the ceiling. I may be wrong, but that does not seem right to me.
2fletch's formula: 32 x (time x time)
Friends formula: ((time x time) x 32.2)) / 2
Basically the results from the same inuputs is one is half of the other. Or twice the other depending on which side of the fence you are on. I am not smart enough to know which formula is correct, but from my gut feeling it is Friends.
Friend, I doubt that you are a redneck, but there really is someone whose user name is "redneck engineer" and he did post the same formula that you did. I'm curious why you would divide the results by 2.
This question has come up before and I believe that it deserves debate and resolution. I know an ex NASA engineer. Maybe I'll get his imput. I don't mind being wrong, but I do want to know the answer.
Cherokee Scout, since the drop occurs all through the distance of the range it wouldn't be necessary to have a 13.5 foot ceiling.
:deadhorse:
Don,
I took that longbow I got from you and shot at a Bison at 66 yards in 3D. I had shot at it before and hit way short. I had to look way above my sight path and try to estimate flight path of the arrow. There was a limb sticking out at about 1/3 the distance that I thought was where I needed to be. It was about 20' off the ground. I lined up on the Bison, drew, shot at the limb so that I would just shoot over it and released. What a heck of an arc at 66 yards. My guess is the arrow reached a peak of 25-30 feet high before dropping into the Bison's hump. I hit inside the 8 ring. I'm guessing my aim was about 40 degrees high from flat. Mabe even close to 45 degrees.
The first shot skipped up into the Bison's midsection the previous tournament when I shot there about two weeks earlier. I hit some quartz on the ground and deflected the arrow into the target. On that shot I thought I was going to shoot over the Bison.
I guess if I shot off the rim of the Grand Canyon and shot level it might go 100 yards out before straight drop took over. The drop curve to get that far out would be interesting to see in graph form.
2315 weighing 544 grains fired from a bow 5 feet above the ground and traveling 170 fps as it leaves the bow would have an apogee of approximately 27.79 inches above line of sight at 21 yards when fired at a target 40 yards away and at 5 feet above the ground. Numbers are approximate due to variables such as wind speed and direction, variations in drag from fletching and shaft finish, etcetera. Note: velocity at target would be approximately 138 fps. The point at which the arrow will cross line of sight will depend on several factors include the distance from your eye to the arrow at full draw.
Note to Bud B... same arrow as above fired at a target 66 yards away would have an apogee of approximately 91.49 inches above LOS at 35 yards.. speed at target 120fps
With my compound I shoot about 10 inches low at 40 with my 30 yard pin (14 inches low with my 20) My recurves are about 100 fps slower I can't believe the drop to be more then double?
After reading this I Missed a 40yd shot on an elk target today. I must not have carried the 1.
All this lobbing the arrow over the moon stuff to make it to the target talk has made lose confidence in my bows. Can anyone recommend a good compound for me? I like to draw short and heal the bow and I shoot better when I snap shoot.
I think Javi did the math. It would really supriuse most folks to see a side on video of them selves shooting at 20, 30, and 40 yards. If you have a video camera, set it up for a side view and shoot all three yardages then view the tape to see the difference. One inch of raised arm height with the bow arm, equates to a lot of elevation and added arc at 30 & 40 yards.
If an arrow is dead level when shot...Don's numbers are very close if not dead on.
What you gotta consider....with most anchors, our eye is above the arrow, so were lauching arrows upwards and as a result, get an arched trajectory.
Shot level...theres no arc, only drop :)
Most don't stop to think that we may look over the arrow point but our anchor and subsequently our arrow nock is way below out eye.The arrow is pointing up but our line of sight is from our pupil,across the tip to our aiming spot.
I thought that sounded like too much drop also.My eye is 2 1/2" above my arrow nock and the arrow is 33" long.My point on is 30 yds.You can do the math and if you draw a line from my eye to the target and draw a line representing how my arrow is pointed,my arrow is actually pointed 81.8" above the target.
It doesn't look like that to me when I shoot as I see the point even with the target but the nock is 2 1/2" lower than my eye.If your nock were even with your eye,you would quickly learn how much drop there really was.
Sorry,I'm a slow typist.
OK, so what is the answer? How much will the arrow drop at 30 yards?
See web-site for Arrow Balistics calculator:
http://www.outdoorsden.com/archery/archbal.asp
I don't do math and calcufiguring when I can keep from it, but I know that my arrows drop too much for me to try and shoot live animals at 30 yards. Targets, sure. But I have yet to try a live shot at that range and doubt I will. Just too little margin for error for me.
Scott,
That I believe that is the real close. I think there is still some environmental and phyiscal factors to consider but darn close.
Good job.
God Bless, Pierre
Thanks for sharing your data,but I still love to shoot my bow and look at the target without calculate too much,that bull elk moves faster of what I count!I get rid of my compound for that reason!
I'm going to try posting a graph that I did a few minutes ago plotting the flight of the arrow versus the point of aim. I hope that it will be readable. I believe that it is reasonable accurate and it gives a good view of how much the arrow drops over 40 yards. Also, it shows that if the archer were launching the arrow at a height of about 5 feet while shooting at a target of 5 feet in height then the arrow would hit an apex of about 9' from the ground.
(http://i109.photobucket.com/albums/n64/2fletch/ArrowFlightChart.jpg)
Cacciatore, I like to occasionally look at the physics of archery then forget it and go shoot.I never want to carry a calculator or wrenches while shooting.
:deadhorse:
Bud B., glad to hear you're shooting regularly. I doubt that you are shooting 45 degrees but you raised another point and that is what is the optimum angle to get maximum distance at a flight shoot. I would guess that to be about 45 degrees. Now we have two topics. Anyone know the answer to that?
Gitty up! :deadhorse:
quote:
Originally posted by 2fletch:
Bud B., glad to hear you're shooting regularly. I doubt that you are shooting 45 degrees but you raised another point and that is what is the optimum angle to get maximum distance at a flight shoot. I would guess that to be about 45 degrees. Now we have two topics. Anyone know the answer to that?
Gitty up! :bigsmyl: optimal angle is just under 45 degrees.
However when shooting into the wind, the angle needs to be about 42 – 43 degrees. But when shooting with the wind the angle should be raised to about 46 – 47 degrees.
I forgot all the math stuff after graduating 10+ years ago. All I know is that tonight I shot one of my favorite pair of shorts off the clothesline when shooting at 30 yards. I was shooting under them... The trajectory caught the bottom of my dang favorite pair shorts! LOL
Good thing its the kinda favorite that the wife would love to throw away.
Shorts shooting regards,
Brian
I have learned that sometimes a formula can be a good place to start. However I am a rifle shooter as well as a trad bowhunter. I have many rifles that according to ballistics formulas should shoot lower at 200 yards than they do at 100 yards but they don't. I don't believe my arrow is dropping 16 feet at 40 yards. It is probably dropping about 8 feet at that distance. By the way one of the rifles I have doesn't drop even a cm from 100 to 300 yards. According to the ballistics table it should be about 6" low. I have come to the conclusion that if you have everything setup exactly like what the formula implies you might get the same results, but otherwise there are to many variables to consider.
2fletch-You may be right. If you aim up 1/2 of the distance it drops, then the drop total could be that much. If you say it is actually dropping 4.5 feet to max height, then the 4.5 back down. Could be correct if that is how you calculate drop.
Cherokee Scout-I'm not sure exctly what you said. You did say "2fletch-You might be right." and I agree that I might be. However that 32.2fps x time squared x 1/2 formula sorta seems odd because it came up twice by different people. Now I'm really interested in finding the answer.
My last physics class was in the 60s. That's so long ago that the laws of physics may have changed (especially under this administration).
Somebody's got to know the math well enough to explain it so the rest of us can understand. Right?
:deadhorse:
quote:
Originally posted by 2fletch:
Bud B., glad to hear you're shooting regularly. I doubt that you are shooting 45 degrees but you raised another point and that is what is the optimum angle to get maximum distance at a flight shoot. I would guess that to be about 45 degrees. Now we have two topics. Anyone know the answer to that?
Gitty up! :thumbsup:
Harry was there. I shot after he did and saw his drop. The aim was way higher than I would have held if I hadn't seen Harry's shot. Arrow speed is in the low 160s.
I'm still looking around for Rhyolite for you. The I-73/311 project uneaarthed alot of rock but I never got to stop and check it out.
Physics 101 is a great course ... D = ½gt²
However, since we don't aim directly at everything regardless of the distance, you need to use the ballistic formulas, corrected for drag, etc. which are major influences on Trad arrow flight.
Although I have a Masters in Physics, I don't think of these things.
My arrows drop the amount I allow for them, based on experience (called hueristics in fancy physics talk).
FWIW, at 30 yds I figure the apogee for 165 fps is about 15" above the sight-target line ... providing I don't put more or less pressure on my third finger, don't put more or less heel into the grip, get the same draw length, and the same 'clean' release, etc. and etc. and etc. ...
Quotewhat is the optimum angle to get maximum distance at a flight shoot. I would guess that to be about 45 degrees. Now... Anyone know the answer to that?
Yeah, it's about 37º when drag is taken into account.
gjarcher, where have you been? Ha! I don't see how the "1/2" apllies to this. What I remember is distance = 32fps x time squared. This of course ignoring atmosphere.
After I posted the last time I saw something about flight shooting that stated that about 45 degrees was optimum depending on wind conditions. I wonder what O L Adcock would say? He's won most of the records.
Bud B, hanging with Harry will get you in trouble. When are you coming back to shoot on Tuesday night? We'll run up a pole at a target outside and put up some markers to determine where Harry's aiming.
"Hi ho Silver Away...Up I Say" :deadhorse:
Ok, so to throw a wrench in the cogs of this conversation. An arrow has to actually have hit a specific height above the ground before it can fall. So despite the excellent example of trajectory drawing shown above I do not think we have resolved the question at hand.
I think we need some clarity on where the arrow is falling or dropping from. If we are measuring from the bow hand then drop will only be the distance below the bow hand and will not include the rise above the hand.
If on the other hand we want to calculate total drop at a set yardarge from the bow hand we have to measure from the top of the arrows arc to the point of arrow impact at that distance.
For this conversation I believe we are looking for the distance the arrow drops based on impact points at 20 yards, 30 yards, and 40 yards. So I would say we need to run the calculations with the zero elevation being a dead on impact point of 20 yards. That leaves the arrow drop at 20 yards as zero. Then it is a simple physics equation to calculate the drop at 30 and 40 yards with the matching arrow weight and velocity.
If someone has a ballistics calculator feel free to run the numbers, if not I will look up the proper trajectory equations and run them.
my head is hurting reading all this! :biglaugh: ... i may need to take a calculator in the stand next time
Bjorn,
Here are the definitive numbers. I used Friends calculator link to run the numbers. With a zero elevation of 20 yards the arrow has not dropped at all. It rose 6.7 inches above the bow hand then fell back to the same height.
At 30 yards the arrow has fallen 20.6 inches below the zero elevation. At 40 yards the arrow has fallen 55.9 inches below the zero elevation. 55.9 / 12 = 4.65 feet of drop below the zero elevation. And that my friends is the laws of physics applied to arrow ballistics.
Mild R/D longbow
Draw Weight 55 lb
584 grain arrow
Assumed velocity of 165 fps
Zero Distance = 20 yards
These numbers reflect the distance for every yard from the hand. Positive numbers are above the bow hand elevation and negative numbers are below the bow hand elevation.
1 1.3
2 2.4
3 3.4
4 4.2
5 5.0
6 5.6
7 6.0
8 6.4
9 6.6
10 6.7
11 6.6
12 6.4
13 6.1
14 5.6
15 5.0
16 4.3
17 3.4
18 2.4
19 1.3
20 0.0
21 -1.4
22 -3.0
23 -4.7
24 -6.5
25 -8.5
26 -10.7
27 -12.9
28 -15.4
29 -17.9
30 -20.6
31 -23.5
32 -26.5
33 -29.7
34 -33.0
35 -36.4
36 -40.0
37 -43.8
38 -47.7
39 -51.7
40 -55.9
QuoteOriginally posted by Ragnarok Forge:
[QB] It rose 6.7 inches above the bow hand then then fell back to the same height.
Did the arrow actually rise ? Or was it launched with an upward angle, to coincide with a chosen zero distance and crossed the line of sight?
I don't understand what the bow hand has got to do with the matter at hand...other than raise or lower the arrow ??? but then again physics is not one of my stronger areas...but I have played the ballistics game a lot of years:0
Rod,
Did the arrow actually rise ? Or was it launched with an upward angle, to coincide with a chosen zero distance and crossed the line of sight?
The arrow was fired at a raised trajectory as you mention. That raised trajectory is what accounts for the arrows rise above the bow hand
To calculate trajectory for any projectile you must have a known starting elevation or a known ending elevation. In the case of archery the starting elevation is always the bow hand and the ending elevation is the X in your target at a set yardage. Setting the zero elevation at 20 yards gives us a fixed ending elevation. This allows the calculator to reverse the math and figure the bow hand elevation as part of the equation. So for a thirty yard shot to hit the target you have to raise the bow hand a set amount that will change the arrow trajectory enough to account for the 20.6 inches of drop.
I've no idea, i never shoot over 15 ...
good luck !
Clay...I'm slow :) I understand the bow hand relevance now....your using the bow hands relationship to the line of sight, to make corrections, instead of the arrow point.
I'm glad I shoot instinctive,this has giving me a headache trying to understand where to aim.
is it hunting season yet?
lol
knowing the physics doesn't hurt, as long as you don't try to apply it to your shooting...
:thumbsup:
Ragnarok, THANK YOU for bringing up those points. I was getting feverish reading through & thinking up how I was going to phrase them.
A projectile has to be launched at an upward angle in order to strike a target of the same height at any range. It will cross line of sight twice. Once on the way up at very short range, and again on "zero". If an arrow is launched from 5' from the ground at a target that is also 5' from the ground, it most certainly rises above the line of sight. The location of the line of sight also changes the apparent drop of a projectile at a given range. In rifles this is the distance between the center-lines of both your scope and bore. Here I suppose it would be from your eye to the arrow.
To further confuse the matter: Ragnarok, do we instinctive shooters always "zero" our trajectory at our currently chosen target? We subconsciously apply the elevation correction to our given distance, so there is no "drop" from line of sight, only from apogee.
I think you'd be shocked at how much an arrow drops in relation to where it's actually pointed. One way to tell is to take one of the laser pointers used to sight in a rifle and insert it into a shaft with no insert in it. Draw the arrow back and aim like you normally would for any given distance. The laser will indicate where the arrow is actually pointed. Just don't shoot it! I'll try it later.
OK So I am hunting on a gentle slope I have my favorite bow that puts a 525 grain arrow, with five inch left wing parabolic feathers and a 160 grain point up front, out at 184fps. the buck is working around towards me and is not at all aware of me. I standup to shoot this time. The buck turns at about 25 yards and is looking away. As I raise my bow I notice a large branch that is 7 of maybe 7.5 feet high 18 yards out. Do I shoot? This is of course not considering tree reach, the ability of trees to stick a pencil sized branch in front a moving arrow with no notice.
Ok, I just went out and tried the laser pointer in the shaft trick. At 30 yards, it looks like the arrow is actually pointing about 4-5 feet above my intended target. I aimed at the handle of my garage door, and the dot was a little above the top edge of the door.
One of my favorite things to do while stump shooting is to hit a target while shooting through a gap in limbs and brush. You really need to know what your arrow trajectory is to be successful at it. I've gotten pretty good at it and the practice really pays off. On a shot at a cottontail this past winter, I had to thread my arrow through a softball-sized opening about 5 yards from the rabbit. It was a perfect shot and I nearly decapitated him with my broadhead.
Pavan, unless you're throwing the arrow, I think you're safe from hitting that branch.
Probably already listed by someone else but didnt read them all.
"The formula for earth's acceleration of gravity for someone who isn't familiar is 32fps x etc etc"
32ft/sec per sec squared is the correct rate of **ACCELERATION of gravity.**
AKA......how much the drop INCREASES IN SPEED per second.......not HOW MUCH it drops.
and.....calucations for gravity are generally taught to be accurate "within a vaccuum" and dont include the many things.........and there are many (most not consistant, day to day) that effect drop in flight.
Atmospheric pressure is but one of these, as you mentioned.
This is why simple calulations of drop dont exist. Each second of projectile flight is not equal in RATE of drop due to gravatational pull, the arrow is also slowing down, and other outside forces take effect as well.
Also consider that the acceleration of speed of drop due to gravity doesnt magically CHANGE in speed of drop AT each second. (no second-third gear, lol) 32fps per second is an "average" used calculating, again, in a vacuum.
The rate of gravitation pull is slowly, throughout flight, increasing in rate of drop AND the FPS of the arrow also changes every micro second. (slowing down lol)
A quick and understandable comparison is that a ball dropped off a building is dropping FASTER EACH second than the second previous to it. (actualy micro second). It is constantly increasing in speed till max gravitational pull is reached. No, I dont recall what that is.
Too difficult for me to even consider calculating.
Just some reading for you of high tech thoughts. lol
http://www.lightandmatter.com/html_books/lm/ch03/ch03.html
but again, I do feel, personally, such calculations reduce the simple beauty of trad archery.
As nicely as I can put this...."who cares?"
Just me, sorry. No offense.
God bless
My arrows drop like a rock... :bigsmyl:
I can agree with that assesment that the arrow would drop nar to the mark that you have quoted.
all this science/physics stuff only goes to prove that the most successful trad bowhunters fling arrows like pitchers throw baseballs - pure "instinct", and both require a LOT of practice and neither are thinking about projectile trajectories. :D
QuoteOriginally posted by Rob DiStefano:
all this science/physics stuff only goes to prove that the most successful trad bowhunters fling arrows like pitchers throw baseballs - pure "instinct", and both require a LOT of practice and neither are thinking about projectile trajectories. :D
Amen!
LOL......how true.
If you wanted to get messed up but good......think of such a trajectory discussion on a basketball (dropping IN a hoop at unknown distances?...uhh) or a GOLF forum.
Less tech information I need to know = more fun for me!!!
:goldtooth:
Even though I have a solid foundation in ballistics, I never think of any of it when I'm shooting a longbow... I look at my target and shoot; trusting my experience and my brain to guide my arrow to its mark. But it's still fun to discuss it occasionally..
We are speaking different languages here. What we need is someone who is bilingual. Forge, I don't doubt the accuracy of your info, it just doesn't answer the question. I'll try again.
First of all, imagine a target at 40 yards and the bullseye at a height of about 5ft which is the same height as the shooter. The range is level so the arrow and the target are on the same level. Now assume that we are on earth and the gravitatioal pull is 32-32.2 fps. Assume (for our purpose) that there is no atmosphere to affect speed or rate of acceleration. Also, there is a backstop wall at the target that is 40 feet tall and marked clearly in 1 inch increments to show the height. Now the question is, "At what height on the wall will the arrow (not sights) be pointed for a bow shooting 170fps to hit the bullseye? The distance from where the arrow is pointed to where it impacts is the total drop. The reason it never reaches that height is because gravity starts working immediately to bring it down.
I looked at some of the trajectory info sites for archery but they seem to be looking at it from the standpoint of where the arrow would impact using one sight pin for the various distances. That's not the same thing.
Get up and Gety up! :deadhorse:
:o :o :coffee: :dunno:
I think the confusion comes from the word "DROP" most folks equate drop to flight path... When in this instance we are talking about one leg of the aiming triangle... | or how high is the aiming point at the prescribed distance which for the original post of 170fps at 40 yards would be approximately 9 ¼ feet... this is what is described as drop in this situation.. the arrow never gets that high because of drag and gravity but you have to aim that high to get there... The arc of the arrow is another thing altogether and as I said earlier the apogee is 27.79 inches above line of sight at 21 yards..
BTW Line of sight is eyeball to target.... not aiming point..
Ay 20 yards you would aim approximately 2 1/8 feet above the target yet the arrow will reach apogee at 12 yards at a height of 4.8" above line of sight.
Interesting, but now I gotta shut all this out for shootin! How am I gonna shoot at 30 yards with thoughts in my head like my arrow is gonna drop 9 feet? :D
Pull to anchor, focus on spot and let her fly! :archer2:
Javi says it well. The "drop" as its being talked about is irrelevant. Apogee is much more a concern for archers, as that is the factor that will determine if your arrow will strike an object such as a branch or fence wire on its path to the target.
Redneck Engineer said it first D = 32.2 x time squared x 1/2, but I didn't get it. Just a few minutes ago I was sitting in the recliner when it occured to me that the formula I was using was for the acceleration of gravity and only gave the speed the arrow was dropping at the end of the 40 yards, not the distance. Dividing by two would give the average speed which would be the approximate distance of the drop.
This all got started because of a guy by the name of Harry who argued that he was only pointing the arrow a few inches over the target that he was shooting at 40 yards. This begain a debate that eventually spilled over to this site. If any of you became confused, dizzy, or disoriented because of the fuzzy numbers, blame Harry it's his fault. Ha! He'll be over here in about 5 hours if you'd like me to pass it on.
Thanks for the fun and knowledge. Now I want to get back on the instinctive side as Rob recommended.
Giddy up and let's get out of town! :deadhorse:
This is why I shoot instinctive. I enjoy the math but I don't bother with it when shooting
Time to put away the calculator and eraser. If I didn't miss by 4 feet obviously it did not drop 4 feet! :bigsmyl:
I have no more idea how much my arrows drop than how much I arc a softball throwing in from left field.
...which is why I sometimes throw into the dugout.
When I shoot, the last thing on my mind is trying to figure the physics. I don't want anything technical to get in the way. Simplicity is what draws me to trad/primitive archery.
One of the Tradgangers sent a pm thanking me for raising this question. I enjoyed the variety of opinions and feel that I learned something as well. :archer2:
QuoteOriginally posted by Ragnarok Forge:
This is why I shoot instinctive. I enjoy the math but I don't bother with it when shooting
I'm primarily a gap shooter and never needed a calculator to kill an animal. I never needed one when I shot instinctively or string-walked either for that matter. Come to think of it, being able to see my arrow in my peripheral vision never caused any of the animals attached to my carcass tags to be any less dead.
Funny how these things work. Either way, deer season opens up north in about two weeks. It's a good thing too. I only have about two deer and a turkey and a half left in the freezer. ;)
This thing about how much your arrow speed drops by 40 yards. when I lived out east of the Mississippi River, a neighbor compound shooter bought a new crono and wondered the same thing. He was comparing the differences between light fat aluminum arrows to skinny carbons at 35 yards. He was concerned about being able to shoot under branches. He practiced at the ranges set up his pins to match both arrows until he was confident in his accuracy. the difference was financially dramatic. He blew up his chronograph box with the first shot, completely missing the loops. If he could not get it right with an overdraw compound and the ability to shoot four inch groups at forty yards, I think that I am better off trusting my gut in tight shooting situations.
I never really put much thought into it till Don brought it up last night. Then I get to thinking about it and start spraying arrows all over the place.............. :dunno:
With my 710 grains arrows out of my 57@31 Schafer I know the drop is big :D
At this range I can not see the target over the arrow amymore:)
QuoteOriginally posted by Ragnarok Forge:
This is why I shoot instinctive. I enjoy the math but I don't bother with it when shooting
On the spot :thumbsup: :archer:
You just have to adjust how you think about the shot. I shoot some 800gr Sweetland Forgewoods that definitely have a different tradgetory than the 585gr Surewood douglas fir shafts I shoot most of the time. But they both shoot and hit their target...most of the time! haha
The apogee (or apex) of the arrow's flight is what most of us are concerned with. How high will the arrow rise before starting to drop to the target is critical if you have a low hanging branch between you and what you are shooting at.
Many years ago I was designated the tournament director for the year at a local club. I ask someone if they would be the range master for the season. Since they had never done that before I also ask a past rangemaster if they would walk the range with the new guy and help us pick sites for the targets and where the stakes should be for X-bows and traditional. On the very first target (which was a javalena down hill and through a thicket with a very low ceiling) he wanted to put the X-bow stake at about 35 yards and the traditional stake at about 32 yards. This was obviously obsurd but he insisted that it should be so. The apogee of any traditional bow shooting under 200fps would have been up in the limbs of the bushs. I guess that was my first serious encounter with trajectory and the law of gravity.
Randy was spraying arrows but I don't think that he was really thinking...,just an excuse.
:archer2:
The sure answer is that the arrow will be dropping all the way.
:notworthy: I bow to the wise elder....or Don
Friend, you're right. Are you going to the IBO? It's right there close to Madisonville. If you do, look me up. I lived in that area as a kid as my dad worked for the L&N Railroad. We moved all along the line until he ended up in Louisville. There's another Tradganger (David Mitchell) who lived for awhile in Providence.
Don't believe Randy, he has a bum foot and can't bow. "Wise elder", I believe that he's taking to much pain killer.
Gotta go finish packing for the IBO. Can't wait to apply some of my new found knowledge. Now I know why I was shooting over the targets, I was using the wrong formula.
We're winning, we're in the lead. Get up I said! :deadhorse:
I suspected that...
2fletch - Looking forward to meeting you in person. My plan is to be there Friday and Saturday then participate in one of the more local shoots on Sunday.
Just a little Aleve from time to time my friend. I refer to you as the wise elder since you have way more grey on top than me! :laughing:
This is fun stuff to look at. Way back when the first cam bows came out Bear Archery came out with a bow they said was the fastest in the world. The Bear Delta V. The Bear Archey Co. came to our annual Broadhead shoot and set up a mini range at our 60 yd. target. They put up a bar set on a frame 15 ft. high half way to the target and had anybody with any bow try and hit the "bales" without going over the bar. They had the only bow that could do it at the time. It is truly amazin how far an arrow really drops.