Home › Forums › Campfire Forum › Does altitude affect arrows?
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I was wondering If I went hunting at altitude, would that affect the flight of my feathered arrows? I know that NHRA dragsters have to make lots of changes when running in say Colorado. Not only does the thin air affect horsepower but the down force is much less and so they adjust the wing for that. My brother lives in Colorado and plays golf. He says he hits much farther there and in Reno than at sea level.
My question is would a person need larger feathers at altitude for the same flight being practiced at sea level since the air is so much thinner? Just a thought.
Kevin:?:
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I live about 600 ft above sea level, but I hunt in Colorado from time to time at 9000 and above. I have found that my arrows fly faster for sure. But I haven’t found that I needed larger fletching.
If you tune your bow/arrow setup, then your arrows will be flying well off your bow no matter the density of the air.
I always look forward to shooting in Colorado. I always shoot better. I usually credit the thin atmosphere for my flatter trajectories.
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Interesting. Can’t say I’d ever really thought about this before, but it gives me another great reason to live at altitude!
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Devil’s Advocate here so no offense intended.
Mathematically the numbers are not there for a noticeable difference.
Tests have been run between sea level and 20,000 feet with bullets very low Ballistic Coefficient (very high “air drag”) at 3000 fps.
At those extreme levels and a horrible bullet the difference in trajectory at 300 YARDS is about 3 inches.
Whatever difference there exists in arrow/fletching performance, at ranges normal to bowhunting, is horrendously miniscule. Gains in usable hunting ranges would be in feet, not yards.
That said…..if you feel there is a difference and more confidence is gained in a change, do so.
Statically very few archers could ACTUALLY “see” a difference simply because the difference would be in decimal point trajectory changes.
On “drag” of the feathers, the atmospheric pressure IS indeed less. Just how much depends on many things.
Should there truly be a LARGE difference compared to my norm, I would strongly dislike that, personally. A change in a practiced trajectory could readily created a miss or poor hit.
If moving to an area of difference atmospheric averages, one simply would do as we have for years. Shoot and tune our set up for the best arrow flight we feel we can get.
God Bless!!
Steve Sr.
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The aerodynamic drag on an arrow is proportional to the Reynolds number, the air density, and the square of the velocity.
Thus, at high speeds, the drag force is much more dependent on the velocity of the projectile. At low speeds, the velocity term does not overshadow the other terms of the equation, namely the density term.
Therefore, one could expect to see some difference in the trajectory of a low velocity projectile over a high velocity projectile as the density of the medium changes.
Is it a lot? Hard to say. One would have to know the Reynolds number of an arrow, which cannot be determined without a wind tunnel.
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Personally I have no experience on this subject.
However, a good friend went to the IBO world when it was held at one of the ski lodges in VA or PA and had problems. He called me asking what to do because as he put it “his arrows were flying hot”. At the time we lived at approx. 600 ft sea level. The lodge was at afew thousand feet higher.
I ask how much hotter and he said at 20yds his arrows were impacting about 2″ high. I would have never thought about it being a problem.
My suggestion was to tie on another set of cat whiskers. Slow down the recovery of the bow by increasing the string weight.
Must have worked,,, cause that was the year he won.
Troy
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I agree with Steve Sr.’s thoughts. To me, this sounds like another one of those things that means more on paper than in reality.
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My experience with a 7.62 rifle zeroed down here at low elevation, high humidity, then taken to a range at about 4500 feet, very low humidity was a negligible difference out to a few hundred metres. My 9mm pistol showed no difference in point of aim at the shorter ranges it was fired (not that I’m a particularly consistent pistol shooter).
It may be more of a factor with arrows (I find Troy’s anecdote about a quality archer noting difference pretty compelling), but if you’re talking about the full effects of elevation on a weapon system I’d be much more concerned about the effects of thinner air on the person moving and powering the bow. In contrast to the negligible effects on my bullets, that same elevation change added about 1 minute (over 10%) to my 2.4km run and drastically extended my recovery time post intense activity. I reckon it was about 2 weeks until I felt properly acclimated.
Jim
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Indeed, once in a while when I’m hunting at tree line my arrows get dizzy the moment I release them and soon fall down. 😆 I find that wood arrows have more altitude issues than carbon, especially if I use low-altitude woods like POC.
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Arrows are people too Dave 😛
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Jim
I would think–more important to you- is the Coriolis effect–don’t you have to aim off to the left or is it right–I never could remember . Watching that water run down the head as we crossed and recrossed the equator–just never got it right or left.:shock:
Semper Fi
Mike
ps. forget the 9mm–use a .45 cal.:D
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Mike, from memory, the fall of shot into the porcelain target had no effect on the efficiency of the flush. No need to aim off.
Jim.
PS
Some men shoot smaller groups, some men shoot bigger bullets 😉
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I would have to agree with Troy as the proof is in the pudding.
Troy Breeding wrote: Personally I have no experience on this subject.
However, a good friend went to the IBO world when it was held at one of the ski lodges in VA or PA and had problems. He called me asking what to do because as he put it “his arrows were flying hot”. At the time we lived at approx. 600 ft sea level. The lodge was at afew thousand feet higher.
I ask how much hotter and he said at 20yds his arrows were impacting about 2″ high. I would have never thought about it being a problem.
My suggestion was to tie on another set of cat whiskers. Slow down the recovery of the bow by increasing the string weight.
Must have worked,,, cause that was the year he won.
Troy
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since you asked, and directly from wikipedia:
“In fluid mechanics, the Reynolds number (Re) is a dimensionless number that gives a measure of the ratio of inertial forces to viscous forces and consequently quantifies the relative importance of these two types of forces for given flow conditions.
The concept was introduced by George Gabriel Stokes in 1851, but the Reynolds number is named after Osborne Reynolds (1842–1912), who popularized its use in 1883.”
Hay, it was invented in the 1800’s. It must be traditional!
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This may be a stretch but here goes…
I am re-reading Asbell as per a recent thread about his books and videos. Based on that reading it seems reasonable to expect a purely instinctive shooter to not have a problem with changes in altitude, humidity, temperature, etc. Instinctive shooting is an eye/hand/brain collaboration which should, or at least could, self-correct for current conditions with just a few practice shots. That assumes that all other equipment variables are stable.
This analysis has face validity in my mind and at bow hunting ranges I think it unlikely that any practical differences caused by altitude would be observable for the vast majority of instinctive shooters.
I live and shoot at 7200′ more or less AND my accuracy is not consistent enough due to “operator error” for me to test this theory.:wink:
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