I always wondered about that one...does one allow for the curvature of the earth's surface falling away which would mean the fired bullet would have further to fall!
Alan
Shooting Up or Down Hill - why aim low?
- Thread starter daw
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I always wondered about that one...does one allow for the curvature of the earth's surface falling away which would mean the fired bullet would have further to fall!
Alan
Essex stalker
Well-Known Member
As they should as they are both being effected by the same gravitational force ie 1G but always found it an interesting one to get your head around, probably why I was an electrical engineer and not a mechanical one!
http://www.wired.com/2009/10/mythbusters-bringing-on-the-physics-bullet-drop/
The Mythbusters did use a slow pistol bullet, I imagine over a longer distance with a rifle the results would be different but much more difficult to measure
The Mythbusters did use a slow pistol bullet, I imagine over a longer distance with a rifle the results would be different but much more difficult to measure
Essex stalker
Well-Known Member
I always wondered about that one...does one allow for the curvature of the earth's surface falling away which would mean the fired bullet would have further to fall!
Alan
I agree with that it only works if you ignore curvature of earth
Ah but doesn't "horizontal" curve from the same centre point as the earths surface?
Alan
Essex stalker
Well-Known Member
Thats a very good question never really thought about it but assuming the word horizontal comes from horizon then it would make complete sense
Essex stalker
Well-Known Member
Just looked it up, horizontal means parellel to the plane of the horizon
Monkey Spanker
Well-Known Member
Nothing to do with that I'm afraid! It's all about gravitational pull on the bullet's flight path which is at a maximum when the bullet is fired parallel with the plane of the horizon. Think of a big long bendy stick! If you hold it straight out horizontally it will be pulled down at the end, much like the path of a fired bullet. If you gradually rotate the bendy stick either upwards or downwards, it will bend gradually less as it approaches the vertical position where it will eventually straighten. That's what is happening to your bullet effectively. Gravity effects lessen on bullet flight path with steepness of angle in either direction. The bullet will therefore go high in either direction, uphill or down. Hope that helps to explain it in simple terms!
MS
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Monkey Spanker
Well-Known Member
Further to my last!
This is an interesting topic as elevation issues can have good and bad effects when it comes to shooting deer!
Firstly, we must consider that a deer is in fact 3 - dimensional. When we shoot about halfway up the animal on flat ground, the bullet should pass roughly through the centre of the middle of the animal (in cross section).
Now consider the same animal and the same point of aim but downhill. The bullet will break the skin at the same entry point but will go well below the centre of the mid point. However, we know that the bullet will go high shooting downhill which is a bonus as we now hit the mid point! This is good as the two effects cancel each other out partially.
Now comes the problem!......
Consider the same animal and the same point of aim but uphill. The bullet will strike the animal but then go well above the midpoint in cross section. Couple this with the effect of the bullet actually striking high and we have an animal either missed or hit VERY high.
Draw a picture and it will make sense!
MS
This is an interesting topic as elevation issues can have good and bad effects when it comes to shooting deer!
Firstly, we must consider that a deer is in fact 3 - dimensional. When we shoot about halfway up the animal on flat ground, the bullet should pass roughly through the centre of the middle of the animal (in cross section).
Now consider the same animal and the same point of aim but downhill. The bullet will break the skin at the same entry point but will go well below the centre of the mid point. However, we know that the bullet will go high shooting downhill which is a bonus as we now hit the mid point! This is good as the two effects cancel each other out partially.
Now comes the problem!......
Consider the same animal and the same point of aim but uphill. The bullet will strike the animal but then go well above the midpoint in cross section. Couple this with the effect of the bullet actually striking high and we have an animal either missed or hit VERY high.
Draw a picture and it will make sense!
MS
Essex stalker
Well-Known Member
Nothing to do with that I'm afraid! It's all about gravitational pull on the bullet's flight path which is at a maximum when the bullet is fired parallel with the plane of the horizon. Think of a big long bendy stick! If you hold it straight out horizontally it will be pulled down at the end, much like the path of a fired bullet. If you gradually rotate the bendy stick either upwards or downwards, it will bend gradually less as it approaches the vertical position where it will eventually straighten. That's what is happening to your bullet effectively. Gravity effects lessen on bullet flight path with steepness of angle in either direction. The bullet will therefore go high in either direction, uphill or down. Hope that helps to explain it in simple terms!
MS
Is that not because force equals mass times the horizontal distance, surely thats what makes the stick bend less as you raise it. The horizontal distance is less.
People from Essex shouldn't really be commenting on shooting up or down hills!
Monkey Spanker
Well-Known Member
No mate. The mass of the stick and distance (length) do not change - just it's angle with respect to gravity (which is also constant).
MS
Monkey Spanker
Well-Known Member
I shoot mainly in Suffolk and Norfolk!
Norfolk definitely doesn't qualify you, and Suffolk only marginally.....
Vipa
Well-Known Member
I always wondered about that one...does one allow for the curvature of the earth's surface falling away which would mean the fired bullet would have further to fall!
Alan
No.. even a fast traveling rifle bullet will hit the dirt very quickly if fired parallel to the ground.. Myth Busters did this.. fired a hand gun parallel to find where the bullet hit the ground an then dropped a bullet from the same height at that distance whilst firing the gun again... both bullets hit the ground simultaneously.
He's from the North. They have hills up there. He must know what he's talking about.
rick6point5
Well-Known Member
Based on some basic math, the earth curves at about 8 inches per mile, for those interested....
Monkey Spanker
Well-Known Member
So, based on that knowledge, if you could fire a bullet that dropped at 8" per mile, and there was no wind resistance, you could in fact shoot yourself in the back of the head!
MS
rick6point5
Well-Known Member
So, based on that knowledge, if you could fire a bullet that dropped at 8" per mile, and there was no wind resistance, you could in fact shoot yourself in the back of the head!
MS
I knew there was a reason for ensuring a safe backstop...
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