Barrel Twist effects on long range shots

[Allen Kitts]

I am curious to see what you guys all do for sighting in your long range rifles at 200 yards as far a windage goes. I went to a long range shooting class where they told us that we should sight our rifles in slightly left of center (1") at 200 yards so that it would keep the bullet still in the kill zone at 1000 yards due to the rifling of the barrel being a right hand twist.
Seemed to make sense to me. I am just wondering how much does the rifle barrel twist rate affect the left and right windage on any given barrel/bullet combination. I am sure there are articles out there I could read on the subject but it is more fun getting insight from all you guys and your experiences. Thanks in advance for indulging me.

 

[Canhunter35]

There's a thread on spin drift on here with lots of good info shared.
Tof makes big difference.
I like to have my zero a hair left rather than a hair right, but other than that, two clicks left at 7-800, 3 clicks for 1000yd works pretty spot on for my 308

 

[Laelkhunter]

Interesting question. I have to keep an eye on this one...........

 

[longrangehunterII]

You can change the parameters in your App at distance and see the difference at + 800 yards. It's not a lot but it is there.

This is why a few guys prefer left hand twist in the Northern Hemisphere which just exacerbates the effect of spin twist on a bullet flight path.