Coriolis Effect

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So if the bullet drops more to the west vs the east I would assume sighting the gun in north or south would be in order?
That way the difference would be cut in half, rather than the full minute if you sighted it in either east or west?

Fortunately for me I just happened to set my rifles up facing south.

At the 1000 yard or longer ranges, where this is said to manifest, one would have to remember this when calculating the east/west shot.

Is there a range finder that recognizes this, compensates and gives correct data ?
 
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Yes. The Sig Kilo 2400 compensates for Coriolis effect


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Theoretically, sighting in north/south there would be a change in azimuth instead of elevation (to a lesser extent). I am by no means a student of long range shooting, so the quantifiable amount it would effect a bullet would be better answered by someone who is. However, based purely on my understanding of physics your impact point when shooting from north to south should be to the right of zero. As such, in a perfect world with no external forces other than the earth's rotation to get a perfect zero you would need to sight in north/south for elevation and east/west for azimuth. Now I may be pole vaulting over mouse turds here (the engineer in me) as variances in wind speed may have a far greater effect and therefore this effect is well within the error bounds of other external forces.

The Sig Kilo 2400 calculates the Coriolis effect purely based on the direction and inclination and does not have a GPS to take latitude into account. From some quick research it is claimed that latitude differences are assumed to be minimal, but I think if you go from AK down to Mexico there may be a difference of an inch or two. Also, keep in mind that the horizontal component Coriolis effect when shooting North/South would change depending on which hemisphere you're in (again, see pole vaulting comment above). I also wonder if taking magnetic north over true north might cause big issues as well at certain latitudes.
 
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OP
mfllood3800
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Do any of you sight in at 200 yrds with your directional being .75 to the left?
Or do you sight L/R while facing E or W and your elev while facing N/S ?

I just purchased a Leica that ranges to around 1200 yrds, but it doesn't have any of the auto calculating features built in ( I didn't discover this need til after the purchase)

So it looks like the Sig 2400 ($1500) on Amazon or the G2 ($1500) at gunwerks
 

Yotekiller

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In my opinion you are better off using an app on your phone to calculate each shot. Then you are able to adjust for barometric pressure, azimuth, incline, wind direction, speed, spin drift, temperature, and distance. Your Leica should provide pressure, incline, temperature, and distance. Then you have adjusted for all the variables for each shot. I use an app called Shooter. Your load data will already be in there so all you need to enter is pressure, distance, wind, azimuth, and incline. It works pretty fast using a Leica rangefinder, compass, and wind meter.
 
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FURMAN

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In the northern hemisphere Coriolis will always cause impact to the right when shooting North/South but will cause impacts to be high or low when shooting East/West. Because of this I would not "zero" my rifle for Coriolis effect. Like Yotekiller said I would calculate each shot.
 

Formidilosus

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Do any of you sight in at 200 yrds with your directional being .75 to the left?
Or do you sight L/R while facing E or W and your elev while facing N/S ?

I just purchased a Leica that ranges to around 1200 yrds, but it doesn't have any of the auto calculating features built in ( I didn't discover this need til after the purchase)

So it looks like the Sig 2400 ($1500) on Amazon or the G2 ($1500) at gunwerks


You are performing ballistic/mental masturbation- depending on cartridge/bullet Coriolis isn't worth worrying about until well past 1k.

Aslo, you should be zeroing at 100, not 200. Start from a POA/POI and calculate from there- do not input variables.
 

Jordan Smith

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In the northern hemisphere Coriolis will always cause impact to the right when shooting North/South but will cause impacts to be high or low when shooting East/West. Because of this I would not "zero" my rifle for Coriolis effect. Like Yotekiller said I would calculate each shot.

Yup
 

Beastmode

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You are performing ballistic/mental masturbation- depending on cartridge/bullet Coriolis isn't worth worrying about until well past 1k.

Aslo, you should be zeroing at 100, not 200. Start from a POA/POI and calculate from there- do not input variables.

I agree. Don’t overthink this. Sight in at 100 and then figure coriolis after 1k.


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mfllood3800
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All my rifles are sighted in at zero, but I know some LR shooters who set up at 200, I think to allow enough MOA adj on their scope to go further out.
I like the 100 and have always used it as it is just easier to figure moa.

Now I am investigating spin drift
lol

I love the technical side of this, way more bits than I ever thought.
I definitely see a new RF in my future.
 

luke moffat

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Why the new rangefinder?

I have a Leica 1600 and it ranges as far as I ever care to shoot.

A $12-$40 ballistics app will do all the sig 2400 computations will do and more. Don’t personally see the advantage there.
 

FURMAN

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Why the new rangefinder?

I have a Leica 1600 and it ranges as far as I ever care to shoot.

A $12-$40 ballistics app will do all the sig 2400 computations will do and more. Don’t personally see the advantage there.

The advantage is speed. I personally do not see myself going back to an app. Having said that to get started I may suggest one of the cheaper Sig rangefinders with an app as Luke suggested.
 
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mfllood3800
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Why the new rangefinder?

I have a Leica 1600 and it ranges as far as I ever care to shoot.

A $12-$40 ballistics app will do all the sig 2400 computations will do and more. Don’t personally see the advantage there.





I did not know this...
I thought people were using a RF that had some of the parameters built in, coupled with an app to complete the needed data for each shot?
I would love to not have to drop another $1500.

I have looked at a few apps and read reviews.
Kind of hard to tell which one is right for simplicity and efficiency
 

KurtR

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You are performing ballistic/mental masturbation- depending on cartridge/bullet Coriolis isn't worth worrying about until well past 1k.

Aslo, you should be zeroing at 100, not 200. Start from a POA/POI and calculate from there- do not input variables.

This is a fact. Get a can of spin D to take care of spin drift

[video=youtube_share;yvl_W-XVXD0]https://youtu.be/yvl_W-XVXD0[/video]
 
OP
mfllood3800
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My RF is the Leica 1600r
It only reads distance along with inclinometer .
It will go the distance I want but that's about it.
 

Yotekiller

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If I were in your shoes I would get a wind meter that can give you barometric pressure, temperature, and wind. I use a Suunto M-9 Wrist Compass for azimuth. That should be all you need for an accurate solution and it doesn't take long after you have practiced with it.
 
OP
mfllood3800
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haha I was just looking at Suunto watches last night, I even put one in my Black Ovis cart.
I wanted one for back country hunts and now it serves a 2 fold purpose which is what I generally use to validate a purchase like that.
Thx
 

4ester

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You should have been looking at spin drift first as it has a greater effect on POI then the earths rotation.


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