I learned about Spindrift from a long range shooter that knows more about it than I do. We sight in a half inch or so to the left at 100 yards. So at around 350 to 400 yds I start drifting a tad to the right at least with my set up.
7mm Rem mag shooting 180gr. Berger?s.
Actually my muzzleloader does the same thing at closer range of coarse.
FYI I use the Hornaday four dimensions of flight (4DOF) Ballistics calculator
If a guy is seeing hits to the right at less than 400yrds, it's likely you are a right hand shooter, it is recoil pushing your body.
Spin drift is real, but not a concern at 6-800 or less, and not much at the thousand.
Shooting a magnum a lot myself, I have learned to get my body more directly behind the recoil, as much as possible.
It affects people more if they are less than 180lb or so in body weight.
I have shared the range with many that claim to get drift to the right because of spin.
Placing the recoil pad more on your peck muscle, just at the shoulder crease helps me dramatically.
I should add that a .30 Cal bullet would have at most around 4-5" actual spin drift at 5-600yrds, and maybe 8-9" at a thousand. High BC bullets would be less than lower BC would and smaller diameter bullets would be less also.
But, the various effects of wind would make determining "actual drift" impossible unless shooting indoors under climate controlled environment.
The wind and the guy behind the gun are the things to be concerned in real life hunting situations.
Spin drift is real. The formula is the following:
Many of the better ballistic programs and solvers have spin drift feature and the windage solutions are usually calculated to include spin drift.
Spin drift is almost always a RH drift due to right hand rifling cut into barrels. Can?t recall ever seeing a LH cut barrel.
>I like the idea of zeroing
>at 600-700 yards so
>you are a little left
>at 100 and a little
>right at 1000.
That's exactly what we do.
Our bench is actually set at 575 yards so that's close enough to shoot good groups and far enough to sight in for windage and this will compensate for most of the spin drift.
The caveat is if your ballistic program solves for spin drift and wind with the same solution. You might over-compensate if you rely on such a program.