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Originally posted by TENRMORE View PostWhy would you use a heavier arrow to go elk hunting?
Usually Kinetic energy is lost with an heavier arrow?
Look at it this way: would it be easier to stop a finishing nail at 400 fps or a railroad spike at 300 fps?
Just a thought...
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Originally posted by TENRMORE View PostWhy would you use a heavier arrow to go elk hunting?
Usually Kinetic energy is lost with an heavier arrow?
Look at it this way: would it be easier to stop a finishing nail at 400 fps or a railroad spike at 300 fps?
Just a thought...
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I'm by no means an archery expert, but weight has nothing to do with gravity. Two objects of different weights will drop at the same rate (not factoring in wind). The only way for a heavier/slower arrow to hit higher than a lighter/faster arrow is because the heavier arrow retained speed better.
Think of it like this, you drop both arrows and they hit the ground at the same time. Lets say it takes 1 second. Even when the arrows are shot (assuming they are shot level) they will still both hit the ground in 1 second (unless there is some form of lift from the vanes, which I doubt there is). So the arrow that travels farther in that 1 second will have a shallower trajectory. If the heavier arrow retains speed better than the lighter arrow, it very well could have a flatter trajectory.
This is thinking of it in terms of bullet ballistics, but it should be a close approximation.
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Originally posted by TENRMORE View PostWhy would you use a heavier arrow to go elk hunting?
Usually Kinetic energy is lost with an heavier arrow?
Look at it this way: would it be easier to stop a finishing nail at 400 fps or a railroad spike at 300 fps?
Just a thought...
50 grains @ 400 FPS = 0.0887 slugs (momentum) & 17.75 Ke
Railroad spike:
7000 grains @ 300 FPS = 9.317 slugs (momentum) & 1397.52 Ke
Definitely easier to stop a finishing nail at these numbers (momentum).
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Originally posted by JustinJ View PostI'm by no means an archery expert, but weight has nothing to do with gravity. Two objects of different weights will drop at the same rate (not factoring in wind). The only way for a heavier/slower arrow to hit higher than a lighter/faster arrow is because the heavier arrow retained speed better.
Think of it like this, you drop both arrows and they hit the ground at the same time. Lets say it takes 1 second. Even when the arrows are shot (assuming they are shot level) they will still both hit the ground in 1 second (unless there is some form of lift from the vanes, which I doubt there is). So the arrow that travels farther in that 1 second will have a shallower trajectory. If the heavier arrow retains speed better than the lighter arrow, it very well could have a flatter trajectory.
This is thinking of it in terms of bullet ballistics, but it should be a close approximation.
Back when I was debating the use of vanes over feathers the consensus was that feathers were faster out of the hole than vanes, but that vanes caught up in speed at about 30 yards.
Even though we are talking about weight vs. drag (in my experiment) the results would be the same, but opposite, as Canny. IOW, the close range pins would move up and the long range pins would stay the same if we started with vanes for sighting in (which I did).
What I found was pretty close to what everyone believed, and well within the margin of error for different bows. IIRC the difference in the two up close was a mere 12(ish) FPS and the vanes caught up in about 35 yards.
The vanes, even though they were heavier, retained their speed better (due to less drag) than the feathers resulting in a flatter trajectory. Not by much, but it was there; mathematically anyway.
So, in my experiment the heavier arrow (by about 15 gr) actually hit the same spot and the lighter arrow hit low at distance beyond 40 yards or so.
It's not just about the weight. The arrow is a dynamic system in and of itself; everything must be considered and gravity isn't the only force acting on an arrow in flight.
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Originally posted by Rat View PostA very good approximation.
Back when I was debating the use of vanes over feathers the consensus was that feathers were faster out of the hole than vanes, but that vanes caught up in speed at about 30 yards.
Even though we are talking about weight vs. drag (in my experiment) the results would be the same, but opposite, as Canny. IOW, the close range pins would move up and the long range pins would stay the same if we started with vanes for sighting in (which I did).
What I found was pretty close to what everyone believed, and well within the margin of error for different bows. IIRC the difference in the two up close was a mere 12(ish) FPS and the vanes caught up in about 35 yards.
The vanes, even though they were heavier, retained their speed better (due to less drag) than the feathers resulting in a flatter trajectory. Not by much, but it was there; mathematically anyway.
So, in my experiment the heavier arrow (by about 15 gr) actually hit the same spot and the lighter arrow hit low at distance beyond 40 yards or so.
It's not just about the weight. The arrow is a dynamic system in and of itself; everything must be considered and gravity isn't the only force acting on an arrow in flight.
i like that
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Originally posted by Rat View PostFinishing nail:
50 grains @ 400 FPS = 0.0887 slugs (momentum) & 17.75 Ke
Railroad spike:
7000 grains @ 300 FPS = 9.317 slugs (momentum) & 1397.52 Ke
Definitely easier to stop a finishing nail at these numbers (momentum).
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if you put your bow in a hooter shooter and aim it at the same spot the heavier arrow will shoot lower every time at every range. there is really no valid argument assuming fundamental equivalence of the arrows other than weight.
heavier arrows will retain a % of initial speed downrange better than a lighter arrow but they start slower so still will drop more by comparison with a lighter arrow at any range.Last edited by Tom; 05-03-2018, 09:59 PM.
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Originally posted by Tom View Postif you put your bow in a hooter shooter and aim it at the same spot the heavier arrow will shoot lower every time at every range. there is really no valid argument assuming fundamental equivalence of the arrows other than weight.
heavier arrows will retain a % of initial speed downrange better than a lighter arrow but they start slower so still will drop more by comparison with a lighter arrow at any range.
How does that fit into your statement about heavier arrows shooting lower every time at EVERY range?
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Originally posted by Tom View Postif you put your bow in a hooter shooter and aim it at the same spot the heavier arrow will shoot lower every time at every range. there is really no valid argument assuming fundamental equivalence of the arrows other than weight.
heavier arrows will retain a % of initial speed downrange better than a lighter arrow but they start slower so still will drop more by comparison with a lighter arrow at any range.
If I build two identical arrows in weight, but one has flu-flu vanes, the flu-flu arrow will not hit the same spot.
The increased drag from the flu-flu vanes will cause the arrow to slow down much faster.
Weight isn't everything...
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