Scope adjustment for spin and wind Help

[DavidleeCole]

Sighting in my rifle if I hit to the right of the bull I put cross hairs on bull and move scope turret/reticle to the right also right on the dial and that has worked great dead on. Now shooting long range no wind both my app and sig 2400 say .25-.50 depending on distance Left for spin drift. I know I'm over thinking this but if my bullet were to impact the target to the right/right hand twist barrel as in sighting in the rifle I would move the turret/reticle to the right to zero so why I'm I questioning the left of the app and sig 2400? I know I'm over thinking this but can someone explain

In sighting in you turn your cross hair to the impact that is after getting back on the bull and then cranking to impact now your point of aim is the impact not the bull. So when you go back to the bull which is in the opposite direction you have moved both point of impact and point of aim to the same place. Spin drift will give you a right shift in point of impact from a right twist. So you must dial left to shift your point of impact to the point of aim. Think of it this way if you were walking to a place down range and you naturally drifted to the right when you walk then when you get there you will be to the right of were you wanted to be. So you have to start out to the left when you go for the walk.

 

[Moose Whacker]

I too have a ZEISS and it is confusing at the range as the hairs move in the opposite direction of any other scope I have, mostly Leupolds. To make my life easier I printed a new direction arrow and adheared them on the Zeiss turrets so now all my scopes adjust the same way, less confusion.

 

[skipglo]

So when you crank your turret left you are moving your cross hairs right. Right hand twist barrel means spin drift right. So if you are hitting right side of target then you would either dial your turret left correction (which moves you reticle right) or simply reticle hold that amount you are hitting to the right on the left side of target. It gets whacky thinking about scopes and how cranking up correction on turret is pushing reticle down and vice versa. So your app is saying .25-.50 left correction which would be on the dial or wind hold that amount with reticle. Spindrift gets a little whacky on out at distance and wind direction now comes into play and the direction of your twist with that wind. Right to left wind usually hits high with rt hand twist, left to right usually hits low with right hand twist. Sometimes these are small amounts never the less another thing to figure out. Great chart here for visual aid.
View attachment 139938

Hey Remy...is the chart for specified wind...is 10 mph or strictly Corellius!

 

[Remmy700]

I will have to look up that article brother I want to say it was fixed 5 mph or something.

 

[Canhunter35]

It does Remmy, I just went and checked to see what was going on this is a new Zeiss scope, If I turn the dial for left wind/left marked on turret it moves the cross hairs left also, so I pulled out another gun with a Leupold and right goes left and left goes right, do you think they put the wrong printed turret on this Zeiss scope or are Zeiss just messed up ?

Zeiss does everything backwards from everyone else. Just turn it the way they indicate

 

[skipglo]

I will have to look up that article brother I want to say it was fixed 5 mph or something.

Thanks man...I am thinking 5-10 for sure...never saw that chart before

 

[skipglo]

Thanks man...I am thinking 5-10 for sure...never saw that chart before

The only true noticeable effect of Coriolis is if the shooter is shooting West or East is it not? West the target is rising and east falling away and truly only definable at 1000 yrds+..or so I was taught

 

[Gregg C]

In

 

[Canhunter35]

The only true noticeable effect of Coriolis is if the shooter is shooting West or East is it not? West the target is rising and east falling away and truly only definable at 1000 yrds+..or so I was taught

Shooting north, bullet is leftt of target, earth is still spinning
South the impact is right. Combination of the two for angle shots

 

[skipglo]

Shooting north, bullet is leftt of target, earth is still spinning
South the impact is right. Combination of the two for angle shots

Got it ! Thanks

 

[Doghunter23]

A lot of detail here if you really want to understand the phenomenon.
I have AB mobile which I cannot recommend highly enough worth every penny! Just know for ELR you should enable Coriolis and enter actual wind speed and Direction along with The azimuth to your target in degrees.

 

[Stgraves260]

So when you crank your turret left you are moving your cross hairs right. Right hand twist barrel means spin drift right. So if you are hitting right side of target then you would either dial your turret left correction (which moves you reticle right) or simply reticle hold that amount you are hitting to the right on the left side of target. It gets whacky thinking about scopes and how cranking up correction on turret is pushing reticle down and vice versa. So your app is saying .25-.50 left correction which would be on the dial or wind hold that amount with reticle. Spindrift gets a little whacky on out at distance and wind direction now comes into play and the direction of your twist with that wind. Right to left wind usually hits high with rt hand twist, left to right usually hits low with right hand twist. Sometimes these are small amounts never the less another thing to figure out. Great chart here for visual aid.
View attachment 139938

Spin drift always gets confusing. The truth is there is no real way to justify for it. What I mean is you would have to set up a 1000 yard indoor range to eliminate spin drift effect. All I can tell you is that when I shoot out 1000 yards I add 1 more MOA of windage when favoring for twist rate. The thang is, is that compasating for twist rate or wind? We will never know cause there is no 1000 + yard indoor range. It would be really nice if some day there would be a 2000 yard indoor range. It would cost a ton of money to do. Could you imagine how tall the roof would be. Holly cow!!. But this would be the only way to see if twist rate even really bothers our long range shooting. My best suggestion is to sight your rifle in at 100 yards. That way you can do all your math out in the field much more easy. 100 yards is a very short range and will eliminate a lot of verbally such as wind and twist rate. If you sight your rifle in at 200 yards lets say with a 10 MPH wind it will move your bullet off center. " You do not have a true zero " You may get 3 bullets in the bull but everything was adjusted and calculated with that 10 MPH wind. So when you check your zero on a different day you find that its off and you don't know how it happened cause you take such good care of your firearm. Hope this shines some lite.

 

[Stgraves260]

A lot of detail here if you really want to understand the phenomenon.
I have AB mobile which I cannot recommend highly enough worth every penny! Just know for ELR you should enable Coriolis and enter actual wind speed and Direction along with The azimuth to your target in degrees.

Good old Rex review. Turn a 5 min conversation into a 3 day corse. LoL But really, he's compleatly legit. Very detailed when explaining thangs.