Since the earth rotates at 1038mph (depending on latitude)it obviouslly has an effect at long ranges. Is there any software that takes into account Lat/long and also direction of fire since it seems it would change POI if you shoot north/south (90deg from rotation) vs east/west (parallel to rotation)?
- Thread starter mram10
- Start date
Re: Rotation of the Earth?
It has been such a long time. I miss the days of spin drift and Coriolis effect discussions.
It has been such a long time. I miss the days of spin drift and Coriolis effect discussions.
Re: Rotation of the Earth?
Its the Lunar pull that will gettcha. Remember it moves oceans!
Its the Lunar pull that will gettcha. Remember it moves oceans!
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body">Since the earth rotates at 1038mph (depending on latitude)it obviouslly has an effect at long ranges. Is there any software that takes into account Lat/long and also direction of fire since it seems it would change POI if you shoot north/south (90deg from rotation) vs east/west (parallel to rotation)?
</div></div>
You played the Call of Duty 4:Modern Warfare level 'One shot, one kill' in the single player campaign... didn't ya?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body">Since the earth rotates at 1038mph (depending on latitude)it obviouslly has an effect at long ranges. Is there any software that takes into account Lat/long and also direction of fire since it seems it would change POI if you shoot north/south (90deg from rotation) vs east/west (parallel to rotation)?
</div></div>
You played the Call of Duty 4:Modern Warfare level 'One shot, one kill' in the single player campaign... didn't ya?
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body">Since the earth rotates at 1038mph (depending on latitude)it obviouslly has an effect at long ranges.</div></div>But not at the Equator.
Mram, would the discrepancy show up as windage or elevation where you are, and why?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body">Since the earth rotates at 1038mph (depending on latitude)it obviouslly has an effect at long ranges.</div></div>But not at the Equator.
Mram, would the discrepancy show up as windage or elevation where you are, and why?
Re: Rotation of the Earth?
If the earth moves at 1038 miles per hour so does your bullet.
What would change that, besides gravity?
Would it slow down to say 900mph (lateral speed relative to earth) and begin to angle right at 138mph?
DTubb gave a few examples here (On this site) and I think it was specific to shooting north only for windage and east/west for elevation.
If the earth moves at 1038 miles per hour so does your bullet.
What would change that, besides gravity?
Would it slow down to say 900mph (lateral speed relative to earth) and begin to angle right at 138mph?
DTubb gave a few examples here (On this site) and I think it was specific to shooting north only for windage and east/west for elevation.
Re: Rotation of the Earth?
COD 4, I don't remember that? I better go try it again
As for the "merry-go-round" analogy, the rotation still has an effect on the bullets path after time. How much? I have no idea, that is why I wanted to pick your brains.
COD 4, I don't remember that? I better go try it again
As for the "merry-go-round" analogy, the rotation still has an effect on the bullets path after time. How much? I have no idea, that is why I wanted to pick your brains.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">But not at the Equator.</div></div>
The Eötvös effect applies even at the equator.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">But not at the Equator.</div></div>
The Eötvös effect applies even at the equator.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">But not at the Equator.</div></div>The Eötvös effect applies even at the equator.</div></div>Ooops. I think I mis-spoke.
Welocme back, Lindy!
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">But not at the Equator.</div></div>The Eötvös effect applies even at the equator.</div></div>Ooops. I think I mis-spoke.
Welocme back, Lindy!
Re: Rotation of the Earth?
OK, OK, enough o' dis messin' with Sasquatch...
Coriolis effect is real, but quite small until distances start getting way beyond where most of us mere mortals are shooting.
It varies with latitude, makes no real difference what direction you're shooting, and unless someone's the caliber of, say, Bobbie Lee Swagger, they probably can't shoot small enough to make any difference whether they try to apply Coriolis correction or not. We're talking a few inches at 1000yd, if that. Most folks are lucky to be able to hold within 2MOA at such distances. We are talking about distances very few people actually shoot at.
It's mainly about hang time, and how much the earth rotates beneath the trajectory while the bullet's in flight. Pretty much, that's the whole tale. In 4 minutes, the earth rotates one degree. The average time of flight to 1Kyd is 1.5 sec. We ain't talkin' about very big numbers at all. By comparison, the bullet drops as much in that 1.5 seconds as the entire earth rotates in 2 minutes. The coriolis effect is 80 times less than drop in that timespan. Fageddabout it.
It's a real question that has significance to maybe as many as 5 people who use this site, and I sure ain't one of 'em.
Greg
OK, OK, enough o' dis messin' with Sasquatch...
Coriolis effect is real, but quite small until distances start getting way beyond where most of us mere mortals are shooting.
It varies with latitude, makes no real difference what direction you're shooting, and unless someone's the caliber of, say, Bobbie Lee Swagger, they probably can't shoot small enough to make any difference whether they try to apply Coriolis correction or not. We're talking a few inches at 1000yd, if that. Most folks are lucky to be able to hold within 2MOA at such distances. We are talking about distances very few people actually shoot at.
It's mainly about hang time, and how much the earth rotates beneath the trajectory while the bullet's in flight. Pretty much, that's the whole tale. In 4 minutes, the earth rotates one degree. The average time of flight to 1Kyd is 1.5 sec. We ain't talkin' about very big numbers at all. By comparison, the bullet drops as much in that 1.5 seconds as the entire earth rotates in 2 minutes. The coriolis effect is 80 times less than drop in that timespan. Fageddabout it.
It's a real question that has significance to maybe as many as 5 people who use this site, and I sure ain't one of 'em.
Greg
Re: Rotation of the Earth?
I agree with Greg ^^. Spin drift is an effect that has more effect on a bullet at the distances most here shoot, and something many don't take into consideration.
Kirk R
I agree with Greg ^^. Spin drift is an effect that has more effect on a bullet at the distances most here shoot, and something many don't take into consideration.
Kirk R
Re: Rotation of the Earth?
i just got the jdm app for itouch and it take coriolis into effect
i just got the jdm app for itouch and it take coriolis into effect
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body">Since the earth rotates at 1038mph (depending on latitude)it obviouslly has an effect at long ranges. Is there any software that takes into account Lat/long and also direction of fire since it seems it would change POI if you shoot north/south (90deg from rotation) vs east/west (parallel to rotation)?
</div></div>
Laod Base 3.0. You can enter the azmuth and directional degee you are shooting. Also your latitude. Then you can check on or off Spin Drift and coriolis.
Actually if your shooting east or west your target is rising or falling.
But I can tell you all adding LB 3.0 with coriolis to my shooting equation did was remove $150 from my pocket, a bunch of 338 bullets and powder from my loading room. The end result is, I found it so small even at 1 mile I could never detect it. The wind and the MOA accuracy of your rifle will cover it up so bad it ain't funny. My advice is spend your $$ on bullets and powder and practice learning to read wind. Oh, the best thing I learned after trying all this was. The chances of a no wind situation is near none. If you think there is not some sort of wind in some location of your bullets path, step out of the vacuum tube.
Jeff
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body">Since the earth rotates at 1038mph (depending on latitude)it obviouslly has an effect at long ranges. Is there any software that takes into account Lat/long and also direction of fire since it seems it would change POI if you shoot north/south (90deg from rotation) vs east/west (parallel to rotation)?
</div></div>
Laod Base 3.0. You can enter the azmuth and directional degee you are shooting. Also your latitude. Then you can check on or off Spin Drift and coriolis.
Actually if your shooting east or west your target is rising or falling.
But I can tell you all adding LB 3.0 with coriolis to my shooting equation did was remove $150 from my pocket, a bunch of 338 bullets and powder from my loading room. The end result is, I found it so small even at 1 mile I could never detect it. The wind and the MOA accuracy of your rifle will cover it up so bad it ain't funny. My advice is spend your $$ on bullets and powder and practice learning to read wind. Oh, the best thing I learned after trying all this was. The chances of a no wind situation is near none. If you think there is not some sort of wind in some location of your bullets path, step out of the vacuum tube.
Jeff
Re: Rotation of the Earth?
I can only, in part agree with some of the statements in this thread regarding secondary calculation functions. It may not always be mandatory to utilize these secondary corrections to effectively engage a target out to 1k - granted, but only if the situation can tolerate minor errors, or a second round contact (sighter shot) if time would not permit these secondary correction calculations.
However, in my opinion, in real world applications, these secondary calculations could become paramount to a mission, at extended ranges (beyond 1k), IF first round contact on a given target were critical to neutralize that target on demand. As it has been said, one good solid hit is better than five close misses - especially if the target has the ability to move from its present location & continue to harass, or potentially pose an actual threat to those that are protected by your precision rifle coverage.
Of course Spin Drift is the larger of the three errors, more so than coriolis deflection, which has two components of error in and of itself. With that said, both are factors that can be readily accounted for with initial corrections on our sights to limit the effects of these factors that amount to further accumulated errors of our bullet path at any given distance, or any given situation, but especially at extended ranges.
I am not trying to fan any debates on this topic, but rather add food for thought for those that desire explore the possibilities, or to gravitate to a realm, over & above the average marksmanship level that some are content with, to ultimately develop the knowledge, skill & ability to readily place first, or second round contacts on targets, on demand, at extended distances.
I don’t care who you are, or how well you can manage your rifle platform, or sights, IMHO, if you are not accounting for these factors at distances beyond 1500 yards, your chances of effectively engaging a human size target with a first round contact will be greatly diminished under actual field shooting conditions, where the marksman has not EVER had the ability to shoot before, rather than at the typical of golf course type, or groomed flat ranges that can serve to develop somewhat of a home court advantages, or bolster our ego‘s in this area.
Personally, if time permits, I will ALWAYS continue to employ these simple secondary function calculations on my sights at any distance past 1k - spin drift if nothing else... To each their own! However, for those reading this thread, don’t be discouraged by the nay say'ers if you want to join those of us that can readily produce bullet contact on our intended targets, on demand. Go for it - nothing to loose & potentially everything to gain!!
Aug ><>
I can only, in part agree with some of the statements in this thread regarding secondary calculation functions. It may not always be mandatory to utilize these secondary corrections to effectively engage a target out to 1k - granted, but only if the situation can tolerate minor errors, or a second round contact (sighter shot) if time would not permit these secondary correction calculations.
However, in my opinion, in real world applications, these secondary calculations could become paramount to a mission, at extended ranges (beyond 1k), IF first round contact on a given target were critical to neutralize that target on demand. As it has been said, one good solid hit is better than five close misses - especially if the target has the ability to move from its present location & continue to harass, or potentially pose an actual threat to those that are protected by your precision rifle coverage.
Of course Spin Drift is the larger of the three errors, more so than coriolis deflection, which has two components of error in and of itself. With that said, both are factors that can be readily accounted for with initial corrections on our sights to limit the effects of these factors that amount to further accumulated errors of our bullet path at any given distance, or any given situation, but especially at extended ranges.
I am not trying to fan any debates on this topic, but rather add food for thought for those that desire explore the possibilities, or to gravitate to a realm, over & above the average marksmanship level that some are content with, to ultimately develop the knowledge, skill & ability to readily place first, or second round contacts on targets, on demand, at extended distances.
I don’t care who you are, or how well you can manage your rifle platform, or sights, IMHO, if you are not accounting for these factors at distances beyond 1500 yards, your chances of effectively engaging a human size target with a first round contact will be greatly diminished under actual field shooting conditions, where the marksman has not EVER had the ability to shoot before, rather than at the typical of golf course type, or groomed flat ranges that can serve to develop somewhat of a home court advantages, or bolster our ego‘s in this area.
Personally, if time permits, I will ALWAYS continue to employ these simple secondary function calculations on my sights at any distance past 1k - spin drift if nothing else... To each their own! However, for those reading this thread, don’t be discouraged by the nay say'ers if you want to join those of us that can readily produce bullet contact on our intended targets, on demand. Go for it - nothing to loose & potentially everything to gain!!
Aug ><>
Re: Rotation of the Earth?
The advances in rifles, ammo components, optics, lasers, etc are opening up precision long range to places it never has been.
In a former life as artillery/ngf FO, I was aware of some of the calculations that go into sending an artillery shell downrange to distant targets typically between 4K-30K meters. Hearing the same factors being used in ELR rifle shooting is not too big of a surprise.
I won't be too surprised to see a fire control computer for rifles in the not too distant future that makes all of the same calculations based on GPS/compass azimuths, and already sensing denisty, temp, azimuth per coriolos, rotation, and so on.
Gun-mounted might pose some shock issues, but even handheld device is realistic.
The real question is how far YOU want to go.
Remember the old timers who scoff advances. Well, at some point we either keep moving, or we become those old timers.
Me personally, I'm continually amazed at how the state of the art continues to advance. I'm not "going there" myself, but I do find it all very impressive.
The advances in rifles, ammo components, optics, lasers, etc are opening up precision long range to places it never has been.
In a former life as artillery/ngf FO, I was aware of some of the calculations that go into sending an artillery shell downrange to distant targets typically between 4K-30K meters. Hearing the same factors being used in ELR rifle shooting is not too big of a surprise.
I won't be too surprised to see a fire control computer for rifles in the not too distant future that makes all of the same calculations based on GPS/compass azimuths, and already sensing denisty, temp, azimuth per coriolos, rotation, and so on.
Gun-mounted might pose some shock issues, but even handheld device is realistic.
The real question is how far YOU want to go.
Remember the old timers who scoff advances. Well, at some point we either keep moving, or we become those old timers.
Me personally, I'm continually amazed at how the state of the art continues to advance. I'm not "going there" myself, but I do find it all very impressive.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">But not at the Equator.
</div></div>
If you cross the equator your bullet spins backwards.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">But not at the Equator.
</div></div>
If you cross the equator your bullet spins backwards.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shot In The Dark</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">But not at the Equator.
</div></div>
If you cross the equator your bullet spins backwards. </div></div>
Not exactly, only the deflection error is opposite - if fired from a right hand twist barrel, the bullet still spins right - but to confuse the issue even more, the effects somewhat (not entirely) cancel one another out which would deviate from your documented data shooting in the northern hem., if you were deployed south of the equator.
Pretty sure on more than one ocassion someone has said, or thought to themselves... -WTF when deployed south of the equator... ;O)
Aug ><>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Shot In The Dark</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Graham</div><div class="ubbcode-body">But not at the Equator.
</div></div>
If you cross the equator your bullet spins backwards. </div></div>
Not exactly, only the deflection error is opposite - if fired from a right hand twist barrel, the bullet still spins right - but to confuse the issue even more, the effects somewhat (not entirely) cancel one another out which would deviate from your documented data shooting in the northern hem., if you were deployed south of the equator.
Pretty sure on more than one ocassion someone has said, or thought to themselves... -WTF when deployed south of the equator... ;O)
Aug ><>
Re: Rotation of the Earth?
thats why ya gotsta run a coriolis compensator device on yer flektard painted sks snipery rifle ninjas.
thats why ya gotsta run a coriolis compensator device on yer flektard painted sks snipery rifle ninjas.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Augustis</div><div class="ubbcode-body">Shane - That integrated technology that you described already exists in the SF community.
Aug ><> </div></div>
That's good to know.
The limited use of supporting arms in our current wars, makes it more of a rifleman's war, so the advanced capabilities are a good thing.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Augustis</div><div class="ubbcode-body">Shane - That integrated technology that you described already exists in the SF community.
Aug ><> </div></div>
That's good to know.
The limited use of supporting arms in our current wars, makes it more of a rifleman's war, so the advanced capabilities are a good thing.
Re: Rotation of the Earth?
It does exist and you NEED to account for it, if you don't, when shooting at a very distant target (lots of elevation correction) you could very possibly hit yourself in the back of the head.
This is serious stuff here fellas, don't discount the potential for disaster!
I have seen it...it is ugly.
It does exist and you NEED to account for it, if you don't, when shooting at a very distant target (lots of elevation correction) you could very possibly hit yourself in the back of the head.
This is serious stuff here fellas, don't discount the potential for disaster!
I have seen it...it is ugly.
Re: Rotation of the Earth?
Using Mr. Litz example from "Applid Ballistics for Long Range Shooting" the effect COULD be 3.1 inches at 1000 yards.
Close to his sample bullet is my 300 WM. A one mile a hour cross wind will move my bullet 6.1 inches or there abouts.
So when I can get to where I can estiment the wind within 1/2 MPH I figure the last thing I need to worry about is Coriolis Effect.
This math is getting out of hand, time I get it all figured out on my slide rule, the critter I"m shooting at will die of old age.
I think I'll spind my efferts on putting rounds down range, when I get to where I can clean a NRA 1000 yard target every time, then I'll start playing with the fancy stuff.
Using Mr. Litz example from "Applid Ballistics for Long Range Shooting" the effect COULD be 3.1 inches at 1000 yards.
Close to his sample bullet is my 300 WM. A one mile a hour cross wind will move my bullet 6.1 inches or there abouts.
So when I can get to where I can estiment the wind within 1/2 MPH I figure the last thing I need to worry about is Coriolis Effect.
This math is getting out of hand, time I get it all figured out on my slide rule, the critter I"m shooting at will die of old age.
I think I'll spind my efferts on putting rounds down range, when I get to where I can clean a NRA 1000 yard target every time, then I'll start playing with the fancy stuff.
Re: Rotation of the Earth?
rotation of the earth relitive to the shooter can only mean one thing....at some point ....its Miller time!
rotation of the earth relitive to the shooter can only mean one thing....at some point ....its Miller time!
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body"> Is there any software that takes into account Lat/long and also direction of fire since it seems it would change POI if you shoot north/south (90deg from rotation) vs east/west (parallel to rotation)?
</div></div>
there many choices of software that have it, i'm runnin FFS delta IV, for use on my 308's and eventually out to a couple K with a M99 416.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: mram10</div><div class="ubbcode-body"> Is there any software that takes into account Lat/long and also direction of fire since it seems it would change POI if you shoot north/south (90deg from rotation) vs east/west (parallel to rotation)?
</div></div>
there many choices of software that have it, i'm runnin FFS delta IV, for use on my 308's and eventually out to a couple K with a M99 416.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">rotation of the earth relitive to the shooter can only mean one thing....at some point ....its Miller time! </div></div>
or Cold Smoke Scotch Ale... but we get your point.
John
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">rotation of the earth relitive to the shooter can only mean one thing....at some point ....its Miller time! </div></div>
or Cold Smoke Scotch Ale... but we get your point.
John
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kraigWY</div><div class="ubbcode-body">Using Mr. Litz example from "Applid Ballistics for Long Range Shooting" the effect COULD be 3.1 inches at 1000 yards.
Close to his sample bullet is my 300 WM. A one mile a hour cross wind will move my bullet 6.1 inches or there abouts.
So when I can get to where I can estiment the wind within 1/2 MPH I figure the last thing I need to worry about is Coriolis Effect.
This math is getting out of hand, time I get it all figured out on my slide rule, the critter I"m shooting at will die of old age.
I think I'll spind my efferts on putting rounds down range, when I get to where I can clean a NRA 1000 yard target every time, then I'll start playing with the fancy stuff.
</div></div>
Kraig
For the sake of discussion only:
Add spin drift to the potential 3.1 MOA right error that already exists and you would get an "accumulated error" of what distance to the right of center of mass, at only 1000 yards??
Aug ><>
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kraigWY</div><div class="ubbcode-body">Using Mr. Litz example from "Applid Ballistics for Long Range Shooting" the effect COULD be 3.1 inches at 1000 yards.
Close to his sample bullet is my 300 WM. A one mile a hour cross wind will move my bullet 6.1 inches or there abouts.
So when I can get to where I can estiment the wind within 1/2 MPH I figure the last thing I need to worry about is Coriolis Effect.
This math is getting out of hand, time I get it all figured out on my slide rule, the critter I"m shooting at will die of old age.
I think I'll spind my efferts on putting rounds down range, when I get to where I can clean a NRA 1000 yard target every time, then I'll start playing with the fancy stuff.
</div></div>
Kraig
For the sake of discussion only:
Add spin drift to the potential 3.1 MOA right error that already exists and you would get an "accumulated error" of what distance to the right of center of mass, at only 1000 yards??
Aug ><>
Re: Rotation of the Earth?
Some of your are so desperate for scientifically backed excuses you'll defy all logic and common sense.
1. Look at the Max Ordnance and Time of flight -- news flash the earth drags its atmosphere, especially at the ground with it. I will gladly pay for an extra hour of flight time with the Helicopter next week to hover at 25ft, well above Max Ord of most small arms to see if Pacific Oceans comes into view. One hour versus a few seconds... To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper.
2. You'll talk about drift on "no wind" days and then go on to talk about the earth's rotation at 1038 mph. So if a bullet can go up 20ft for 3 seconds, and have the earth move away under it how can you have a no wind day ? It's impossible, any puff of smoke from a chimney will be streak in the sky as it leaves the house. Or a flag on a flagpole that is 50ft up, no way the flag isn't moving. No Wind days would be a physical impossibility by your logic. A bullet doesn't go nearly as high and yet, you have this scientific proof to back up misses.
Yes the earth spins and yes if you go up high enough, long enough it will move from under you... but with small arms -- forget about it, more noise from the science excuse club.
I'm thinking about taking up a collection for a bet about that extended distance stuff <span style="text-decoration: underline">on demand,</span> because I don't see on demand under field conditions happening at 1000 yards in high percentages, maybe less than 10%, let alone beyond 1500m. So I want to know what "on demand" means and where I can watch it ? First round ? Cause that is one demand means to me... where can come for this and how much will it cost me. Please send an audition tape showing me your trigger squeeze before I take the trip. I'm not paying for a guy who dials out his shooter errors under the guise of science.
2 Mils in 20... remember that... 2 mils in 20.
Some of your are so desperate for scientifically backed excuses you'll defy all logic and common sense.
1. Look at the Max Ordnance and Time of flight -- news flash the earth drags its atmosphere, especially at the ground with it. I will gladly pay for an extra hour of flight time with the Helicopter next week to hover at 25ft, well above Max Ord of most small arms to see if Pacific Oceans comes into view. One hour versus a few seconds... To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper.
2. You'll talk about drift on "no wind" days and then go on to talk about the earth's rotation at 1038 mph. So if a bullet can go up 20ft for 3 seconds, and have the earth move away under it how can you have a no wind day ? It's impossible, any puff of smoke from a chimney will be streak in the sky as it leaves the house. Or a flag on a flagpole that is 50ft up, no way the flag isn't moving. No Wind days would be a physical impossibility by your logic. A bullet doesn't go nearly as high and yet, you have this scientific proof to back up misses.
Yes the earth spins and yes if you go up high enough, long enough it will move from under you... but with small arms -- forget about it, more noise from the science excuse club.
I'm thinking about taking up a collection for a bet about that extended distance stuff <span style="text-decoration: underline">on demand,</span> because I don't see on demand under field conditions happening at 1000 yards in high percentages, maybe less than 10%, let alone beyond 1500m. So I want to know what "on demand" means and where I can watch it ? First round ? Cause that is one demand means to me... where can come for this and how much will it cost me. Please send an audition tape showing me your trigger squeeze before I take the trip. I'm not paying for a guy who dials out his shooter errors under the guise of science.
2 Mils in 20... remember that... 2 mils in 20.
Re: Rotation of the Earth?
If I learn to levitate, will I get a speeding ticket?
If I learn to levitate, will I get a speeding ticket?
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">But not at the Equator.</div></div>
The Eötvös effect applies even at the equator.
</div></div>
Except San Francisco, where they instead have the cornholeis effect.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lindy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">But not at the Equator.</div></div>
The Eötvös effect applies even at the equator.
</div></div>
Except San Francisco, where they instead have the cornholeis effect.
Re: Rotation of the Earth?
Will the water of a flushed toilet on the Equator still spin?
Will the water of a flushed toilet on the Equator still spin?
Re: Rotation of the Earth?
let me ask this:
Assume we are shooting a thousand yard target. Again according to the example in Litz' book, for the sake of arguement, the coriolis effects my bullet 3.1 inches. At what point does the effect happen. At 1000, at 100, at 500??
I contend that it starts the instant the bullet leaves the barrel, its angular like MOA, based on TOF. So if effect is 3.1 inches at 1000 yards, wouldnt it be .31 inches at 100 yards.
If its happening, from the time the bullet leaves the barrel, and continues until the bullet stops, then when we sight our rifle in, lets say, @ 200 yards, then don't we adjust for it. Say there is no wind, so wouldn't we automaticly plug in the .62 (the effect at 200 yards, with automaticly in incorporated in our Zero.
I'm jus throwing this out as a question, maybe some of you math guys can answer it.
I'm not gonna loose any sleep over it though, my interest now has drifted to CMP GSM shooting. I don't think I could tell the differance, (even if I knew what I was doing) shooting a as issued Garand or Carbine.
let me ask this:
Assume we are shooting a thousand yard target. Again according to the example in Litz' book, for the sake of arguement, the coriolis effects my bullet 3.1 inches. At what point does the effect happen. At 1000, at 100, at 500??
I contend that it starts the instant the bullet leaves the barrel, its angular like MOA, based on TOF. So if effect is 3.1 inches at 1000 yards, wouldnt it be .31 inches at 100 yards.
If its happening, from the time the bullet leaves the barrel, and continues until the bullet stops, then when we sight our rifle in, lets say, @ 200 yards, then don't we adjust for it. Say there is no wind, so wouldn't we automaticly plug in the .62 (the effect at 200 yards, with automaticly in incorporated in our Zero.
I'm jus throwing this out as a question, maybe some of you math guys can answer it.
I'm not gonna loose any sleep over it though, my interest now has drifted to CMP GSM shooting. I don't think I could tell the differance, (even if I knew what I was doing) shooting a as issued Garand or Carbine.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kraigWY</div><div class="ubbcode-body">let me ask this:If its happening, from the time the bullet leaves the barrel, and continues until the bullet stops, then when we sight our rifle in, lets say, @ 200 yards, then don't we adjust for it. Say there is no wind, so wouldn't we automaticly plug in the .62 (the effect at 200 yards, with automaticly in incorporated in our Zero.</div></div>
Depends on latitude and direction of fire.......
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: kraigWY</div><div class="ubbcode-body">let me ask this:If its happening, from the time the bullet leaves the barrel, and continues until the bullet stops, then when we sight our rifle in, lets say, @ 200 yards, then don't we adjust for it. Say there is no wind, so wouldn't we automaticly plug in the .62 (the effect at 200 yards, with automaticly in incorporated in our Zero.</div></div>
Depends on latitude and direction of fire.......
Re: Rotation of the Earth?
Don't know about software for this. I do know the only other people that I know of that cared about this issue were the FCs and GMs on the USS IOWA. With 16" 50 cal shooting out to ~25 miles, such corrections mattered.
They didn't let me do much with the 16" - other than the occasional call for fire and spotting. That was fun. 5" 38 was what I got to shoot most, as a secondary battery directory officer.
The Mk 8 Rangekeeper was a box down in the fire control room, about 3.5' on a side - kind of tough to tote around. Plus, it was all cams and diodes and electro-mechanical switches.
from wiki - The Mk8 Rangekeeper was an electromechanical analog computer[10][12][unreliable source?] whose function was to continuously calculate the gun's bearing and elevation, Line-Of-Fire (LOF), to hit a future position of the target. It did this by automatically receiving information from the director (LOS), the FC Radar (range), the ship's gyrocompass (true ship's course), the ships Pitometer log (ship's speed), the Stable Vertical (ship's roll and pitch), and the ship's anemometer (relative wind speed and direction). Also, before the surface action started, the FT's made manual inputs for the average initial velocity of the projectiles fired out of the battery's gun barrels, and air density. With all this information, the rangekeeper calculated the relative motion between its ship and the target.[10] It then could calculate an offset angle and change of range between the target's present position (LOS) and future position at the end of the projectile's time of flight. To this bearing and range offset, it added corrections for gravity, wind, Magnus Effect of the spinning projectile, earth's curvature, and coriolis effect. The result was the turret's bearing and elevation orders (LOF).[10] During the surface action, range and deflection Spots and target altitude (not zero during Gun Fire Support) were manually entered
Don't know about software for this. I do know the only other people that I know of that cared about this issue were the FCs and GMs on the USS IOWA. With 16" 50 cal shooting out to ~25 miles, such corrections mattered.
They didn't let me do much with the 16" - other than the occasional call for fire and spotting. That was fun. 5" 38 was what I got to shoot most, as a secondary battery directory officer.
The Mk 8 Rangekeeper was a box down in the fire control room, about 3.5' on a side - kind of tough to tote around. Plus, it was all cams and diodes and electro-mechanical switches.
from wiki - The Mk8 Rangekeeper was an electromechanical analog computer[10][12][unreliable source?] whose function was to continuously calculate the gun's bearing and elevation, Line-Of-Fire (LOF), to hit a future position of the target. It did this by automatically receiving information from the director (LOS), the FC Radar (range), the ship's gyrocompass (true ship's course), the ships Pitometer log (ship's speed), the Stable Vertical (ship's roll and pitch), and the ship's anemometer (relative wind speed and direction). Also, before the surface action started, the FT's made manual inputs for the average initial velocity of the projectiles fired out of the battery's gun barrels, and air density. With all this information, the rangekeeper calculated the relative motion between its ship and the target.[10] It then could calculate an offset angle and change of range between the target's present position (LOS) and future position at the end of the projectile's time of flight. To this bearing and range offset, it added corrections for gravity, wind, Magnus Effect of the spinning projectile, earth's curvature, and coriolis effect. The result was the turret's bearing and elevation orders (LOF).[10] During the surface action, range and deflection Spots and target altitude (not zero during Gun Fire Support) were manually entered
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">rotation of the earth relitive to the shooter can only mean one thing....at some point ....its Miller time! </div></div>
I'll bring the popcorns. LOL.
In all seriousness, my understanding of this, and I may be wrong, is the launch angle. If you are launching verically, like a rocket or an ICBM, and the MAx ord is very high (low geosyn. orbit and such), then you have to take into account the rotation of the earth into the calculation of your target. Otherwise, you will be off.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: BOLTRIPPER</div><div class="ubbcode-body">rotation of the earth relitive to the shooter can only mean one thing....at some point ....its Miller time! </div></div>
I'll bring the popcorns. LOL.
In all seriousness, my understanding of this, and I may be wrong, is the launch angle. If you are launching verically, like a rocket or an ICBM, and the MAx ord is very high (low geosyn. orbit and such), then you have to take into account the rotation of the earth into the calculation of your target. Otherwise, you will be off.
Re: Rotation of the Earth?
In FC "A" school where I did a crap load of these stupid calculations 20+ years ago we did not take it into account. Even with over the horizon targets. Can't be to dang important. trust me on this fact, if it mattered Master Chief would have grilled our butts on it.
In FC "A" school where I did a crap load of these stupid calculations 20+ years ago we did not take it into account. Even with over the horizon targets. Can't be to dang important. trust me on this fact, if it mattered Master Chief would have grilled our butts on it.
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper. </div></div>
Yeah, assuming you want to vacation somewhere to the west. You want to go to the east, it's going to take awhile (I think
).
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper. </div></div>
Yeah, assuming you want to vacation somewhere to the west. You want to go to the east, it's going to take awhile (I think
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper. </div></div>
Shooting to 2000-3000 yards, with a max ord around 100 ft above LOS, and a TOF in excess of 4 seconds might introduce some variables that are irrelevant with the 308 at ranges out to 800-1000 yards.
Can't say I know for sure, but it seems plausible to me.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper. </div></div>
Shooting to 2000-3000 yards, with a max ord around 100 ft above LOS, and a TOF in excess of 4 seconds might introduce some variables that are irrelevant with the 308 at ranges out to 800-1000 yards.
Can't say I know for sure, but it seems plausible to me.
Re: Rotation of the Earth?
I am glad in NZ we have found out the earth turns out to be flat -no problem with evotis or spin drift
I am glad in NZ we have found out the earth turns out to be flat -no problem with evotis or spin drift
Re: Rotation of the Earth?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MontanaMarine</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper. </div></div>
Shooting to 2000-3000 yards, with a max ord around 100 ft above LOS, and a TOF in excess of 4 seconds might introduce some variables that are irrelevant with the 308 at ranges out to 800-1000 yards.
Can't say I know for sure, but it seems plausible to me.</div></div>
Ha, like you can judge anything at that range, wind within 1mph, no way. So how do you know what variables are causing what?
Did you not see Mcmillan & Spicer not hit at 2500m or even see where they hit? On TV.
Besides TOF for a 338 to 1500 is only 2.25 secs, I can throw baseball straight up and hang it in the air longer.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: MontanaMarine</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lowlight</div><div class="ubbcode-body">To believe this is to believe you can hover in a lawn chair suspended by helium balloons at 15ft<span style="font-style: italic"> (Max Ord of a 308)</span> and the world will turn under you. Vacations just got a whole lot cheaper. </div></div>
Shooting to 2000-3000 yards, with a max ord around 100 ft above LOS, and a TOF in excess of 4 seconds might introduce some variables that are irrelevant with the 308 at ranges out to 800-1000 yards.
Can't say I know for sure, but it seems plausible to me.</div></div>
Ha, like you can judge anything at that range, wind within 1mph, no way. So how do you know what variables are causing what?
Did you not see Mcmillan & Spicer not hit at 2500m or even see where they hit? On TV.
Besides TOF for a 338 to 1500 is only 2.25 secs, I can throw baseball straight up and hang it in the air longer.
Re: Rotation of the Earth?
It's not about what I can judge, or not judge. I plainly said I don't know for sure.
I'm just saying that in the realm of ELR there COULD be some more variables that are correctable, and I'm open minded about such things.
It's not about what I can judge, or not judge. I plainly said I don't know for sure.
I'm just saying that in the realm of ELR there COULD be some more variables that are correctable, and I'm open minded about such things.
Re: Rotation of the Earth?
I didn't see the tv show.
I know Aug and some of his shooting associates are hitting targets at ranges approaching 3000 yards. The TOFs and max ord are considerably greater at those distances than they are at 1500 yards.
I didn't see the tv show.
I know Aug and some of his shooting associates are hitting targets at ranges approaching 3000 yards. The TOFs and max ord are considerably greater at those distances than they are at 1500 yards.
Re: Rotation of the Earth?
Whatever, I'll pay for the helo to hover at 100ft.
It's less than 1% if that at 1500m, beyond 2000 is simply not practical, it's a fad. Not to mention the results are less than reliable.
I'll use the radio to call in a strike and get Them all instead of one.
When was the last time they tried hitting a mover because that is what they would be shooting at?
Whatever, I'll pay for the helo to hover at 100ft.
It's less than 1% if that at 1500m, beyond 2000 is simply not practical, it's a fad. Not to mention the results are less than reliable.
I'll use the radio to call in a strike and get Them all instead of one.
When was the last time they tried hitting a mover because that is what they would be shooting at?
Re: Rotation of the Earth?
Shoot at 1500-3000 yards and not consider these fairly simple things? Much simpler than judging the wind or even thermals coming off the ground. If they are simple to correct for do it. Why not?
Is it not foolish to say since you can't judge wind correctly why correct for small known consistant variables. Am I reading this wrong LL?
Shoot at 1500-3000 yards and not consider these fairly simple things? Much simpler than judging the wind or even thermals coming off the ground. If they are simple to correct for do it. Why not?
Is it not foolish to say since you can't judge wind correctly why correct for small known consistant variables. Am I reading this wrong LL?
Re: Rotation of the Earth?
Earth rotation is calculated in artillery technical fire control. I can't speak to it in detail, because I was "on the hill".
Wether it is a predictable variable that can be corrected for in ELR is worth exploring, in my opinion. Maybe it is, maybe it isn't.
In our current wars, supporting arms are limited in their use, and often less than timely when they are allowed. It has become a modern rifleman's war, in many regards.
That is good for further advances in sniper rifles. We'll see where it goes.
Earth rotation is calculated in artillery technical fire control. I can't speak to it in detail, because I was "on the hill".
Wether it is a predictable variable that can be corrected for in ELR is worth exploring, in my opinion. Maybe it is, maybe it isn't.
In our current wars, supporting arms are limited in their use, and often less than timely when they are allowed. It has become a modern rifleman's war, in many regards.
That is good for further advances in sniper rifles. We'll see where it goes.
Re: Rotation of the Earth?
Broz, jrob, and I were playing at 2300 yards recently. jrob's 300 WinMag loading of a 208 AMax at 2870 fps was making repeatable accurate shots at almost 2300. His TOF was right around 4.4 seconds, with a max ord of about 84 ft above LOS, at about the 1375 yard mark.
Granted, we were on a one-way range.
Broz, jrob, and I were playing at 2300 yards recently. jrob's 300 WinMag loading of a 208 AMax at 2870 fps was making repeatable accurate shots at almost 2300. His TOF was right around 4.4 seconds, with a max ord of about 84 ft above LOS, at about the 1375 yard mark.
Granted, we were on a one-way range.
Re: Rotation of the Earth?
84ft at 1375, really, maybe closer to 55 which Is sea level. , and at what altitude were you shooting? Which also changes things, considerably.
Calculate for all the variables you think you have, but most people can't handle themselves let alone the conditions.
How many rounds to get on target? Most of the ELR guys tend to leave that out.
I would check your math, refigure the altitude and run the numbers again.
Also what was the angle?
84ft at 1375, really, maybe closer to 55 which Is sea level. , and at what altitude were you shooting? Which also changes things, considerably.
Calculate for all the variables you think you have, but most people can't handle themselves let alone the conditions.
How many rounds to get on target? Most of the ELR guys tend to leave that out.
I would check your math, refigure the altitude and run the numbers again.
Also what was the angle?
Similar threads
