Long Range Hunting Online Magazine


Go Back   Long Range Hunting Online Magazine > Hunting > Long Range Hunting & Shooting

Long Range Hunting & Shooting Nightforce Optics


Reply

Coriolis Effect Questions

 
LinkBack Thread Tools Display Modes
  #1  
Old 07-10-2010, 01:37 AM
Gold Member
 
Join Date: Apr 2009
Location: Carrollton, Ohio
Posts: 578
Coriolis Effect Questions

I was trying to figure out the specifics on Coriolis Effect and keep finding conflicting information. I remember seeing an old thread in here where someone was wondering why their POI was off and it was determined that it was due to Coriolis Effect. I can't find that thread, and was pretty hard to follow because there was a lot of conflicting information in there also.

So I was wondering if someone could provide a simple explanation and answer a few questions.

(I use "drift" because I don't know a better word to use.)

1.) A bullet will drift to the right in the northern hemisphere and drift left in the southern hemisphere, no matter what direction the shot is directed. Correct?

2.) Assuming the above is correct, is the strength of drift equal shooting in all directions?

3.) POI height; drifts low shooting West, high East?

4.) There is less Coriolis Effect at the equator than there is at the polls. Is that true for both the right/left drift and the POI height?

Sorry for all the questions, just trying to understand the Coriolis Effect better.
__________________
"If you love wealth more than liberty, the tranquility of servitude better than the animating contest of freedom, depart from us in peace. We ask not your counsel nor your arms. Crouch down and lick the hand that feeds you. May your chains rest lightly upon you and may posterity forget that you were our countrymen."-- Samuel Adams
Reply With Quote
  #2  
Old 07-10-2010, 02:16 AM
Platinum Member
 
Join Date: Apr 2005
Location: Alaska
Posts: 3,368
Re: Coriolis Effect Questions

Quote:
Originally Posted by justgoto View Post
I was trying to figure out the specifics on Coriolis Effect and keep finding conflicting information. I remember seeing an old thread in here where someone was wondering why their POI was off and it was determined that it was due to Coriolis Effect. I can't find that thread, and was pretty hard to follow because there was a lot of conflicting information in there also.

So I was wondering if someone could provide a simple explanation and answer a few questions.

(I use "drift" because I don't know a better word to use.)

1.) A bullet will drift to the right in the northern hemisphere and drift left in the southern hemisphere, no matter what direction the shot is directed. Correct? Correct.

2.) Assuming the above is correct, is the strength of drift equal shooting in all directions? The magnitude of horizontal drift is equal in all directions for a given Latitude.

3.) POI height; drifts low shooting West, high East? Correct.

4.) There is less Coriolis Effect at the equator than there is at the polls. Is that true for both the right/left drift and the POI height? Yes for horizontal (right/left) drift. No for vertical drift. Vertical deflection from Coriolis is maximum at the equator, null at the two poles.

Sorry for all the questions, just trying to understand the Coriolis Effect better.
Check out this Thread, starting at about post #84:
Help Needed with LB3.0 and .338 Bergers

Last edited by phorwath; 08-02-2010 at 09:42 PM. Reason: Correction in response to item 4.) Edit is underlined.
Reply With Quote
  #3  
Old 07-10-2010, 02:46 AM
Gold Member
 
Join Date: Apr 2009
Location: Carrollton, Ohio
Posts: 578
Re: Coriolis Effect Questions

Quote:
Originally Posted by phorwath View Post
Check out this Thread, starting at about post #84:
Help Needed with LB3.0 and .338 Bergers

I found an informative post here also.

Rotation of the Earth stuff:
On all bearings of fire a 0.1mil left correction is required (ie 20cm at this range).
Easterly fire requires an elevation reduction equivalent to the target being 13 metres closer.
Westerly fire requires an elevation increase equivalent to the target being 13 metres further away.
(in both cases this value gradually reduces to zero as the bearing moves to due N or S.)

Bet that's surprised a few people!


Thanks!
__________________
"If you love wealth more than liberty, the tranquility of servitude better than the animating contest of freedom, depart from us in peace. We ask not your counsel nor your arms. Crouch down and lick the hand that feeds you. May your chains rest lightly upon you and may posterity forget that you were our countrymen."-- Samuel Adams
Reply With Quote
  #4  
Old 07-10-2010, 04:24 AM
Platinum Member
 
Join Date: Feb 2005
Location: Nevada
Posts: 2,782
Re: Coriolis Effect Questions

Quote:
Originally Posted by phorwath View Post
Check out this Thread, starting at about post #84:
Help Needed with LB3.0 and .338 Bergers
Quote:
4.) There is less Coriolis Effect at the equator than there is at the polls. Is that true for both the right/left drift and the POI height? Yes. In fact there is basically no right/left drift at the equator. Basically no vertical drift at the equator either - at least out to a 3000 yd distance.
From the site

Spin and Coriolis Drift

I copied the following statement:

Quote:
The vertical component is at a maximum at the equator, and goes to zero at the poles.
I wouldn't be surprised if I'm miss understanding something!
__________________
-----------------------------

-----------------------------
HEBREWS 13:8
Jesus Christ the same yesterday, and to day, and for ever.

Our Lord Jesus said that as it was in the days of Noah and
also as it was in the days of Lot so it shall be in the days...
It's happening again!!! God sent to us His prophet, and His Word
to this generation and we once more are rejecting it as was prophesied!!!

---> As promised, God Sent His Prophet to us!
Reply With Quote
  #5  
Old 07-10-2010, 09:22 AM
Platinum Member
 
Join Date: Apr 2005
Location: Alaska
Posts: 3,368
Re: Coriolis Effect Questions

Quote:
Originally Posted by Eaglet View Post
From the site

Spin and Coriolis Drift

I copied the following statement:


Quote:
The vertical component of Coriolis is at a maximum at the equator, and goes to zero at the poles.

I wouldn't be surprised if I'm miss understanding something!
Eaglet,
Between the time I posted my original reply (7/10/10) and today, August 22, 2010, I've spent hours researching this. I have concluded that the vertical deflection caused by Coriolis force is indeed at a maximum value at the equator, and null at both poles. This is also how Patagonia Ballistics LoadBase 3.0 Desktop software currently models vertical deflection due to Coriolis force. Your post/statement was, and currently is, correct - to the best of my knowledge, understanding, and belief.

With this edit, I have deleted my original response as an effort to minimize confusion, and to provide correct information.

Last edited by phorwath; 08-02-2010 at 10:01 PM. Reason: Remove errant information and provided correct information on vertical deflection caused by Coriolos force.
Reply With Quote
  #6  
Old 07-10-2010, 12:34 PM
Gold Member
 
Join Date: Jan 2003
Location: North Louisiana
Posts: 576
Re: Coriolis Effect Questions

Cost too damn much to travel to the equator and the Poles to shoot so I guess I'll just keep me Irish hinney here and burn up in North Louisiana!!
__________________
United States Marines: Giving the enemies of America a chance to die for their cause since 1775!
Reply With Quote
  #7  
Old 07-12-2010, 01:25 PM
tlk tlk is offline
Silver Member
 
Join Date: Apr 2008
Posts: 238
Re: Coriolis Effect Questions

Honest question: at what distance does all of this become material?
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes


Similar Threads for: Coriolis Effect Questions
Thread Thread Starter Forum Replies Last Post
spin drift & Coriolis effect rem Long Range Hunting & Shooting 41 05-19-2014 11:34 AM
Can't find my spin drift or coriolis. lisagrantb Long Range Hunting & Shooting 21 04-02-2011 01:22 PM
A new spin drift and coriolis question (I think) Exbal jmason Rifles, Bullets, Barrels and Ballistics 15 12-13-2010 07:11 PM
Coriolis effect Blaine Fields Rifles, Bullets, Barrels and Ballistics 46 03-17-2007 01:22 AM
Magnus Effect vs. Spin Effect Brent Rifles, Bullets, Barrels and Ballistics 2 12-26-2002 05:27 PM

Current Poll
Where in the US do you live?
West of the Mississippi River - 61.19%
938 Votes
East of the Mississippi River - 36.59%
561 Votes
On the Mississippi River on a houseboat - 2.22%
34 Votes
Total Votes: 1,533
You may not vote on this poll.

All times are GMT -5. The time now is 11:59 PM.


Powered by vBulletin ©2000 - 2014, Jelsoft Enterprises Ltd.
Content Management Powered by vBadvanced CMPS
All content ©2010-2014 Long Range Hunting, LLC