Dialling for spin drift?

[DenisA]

G'day All. Just wondering how many of us dial for spindrift prior to a match, prior to adjusting for wind or holding off, as you move out further?

[johnk]

Just carefully set your scope for the right skew off plumb when you install it.

[plumbs7]

G'day All. Just wondering how many of us dial for spindrift prior to a match, prior to adjusting for wind or holding off, as you move out further?

Yep I do Denis . When U see my setup next time I have a fancy movable dial indicator on my scope that I move as the further we go out . I use to have it 100 m windage zero and then calc from there .
But later found doing it this other way was good for on the fly windage changes and Les prone to errors. With the .308 155's at 1000 yds it's a whole Moa left . Half Moa at 500 yds or half 6 ring . So can't be just overlooked!

[lewis reynolds]

i set my scope up using a string line and a tall taget test my 25 yard zero it printing but still touching the left side of the line. i then wind up to my 1000 yard elevation and have my group print just to the right but still touching the line. once this is set and rings are tight i attach my anti cant level. auto spin drift compensator

[DenisA]

i set my scope up using a string line and a tall taget test my 25 yard zero it printing but still touching the left side of the line. i then wind up to my 1000 yard elevation and have my group print just to the right but still touching the line. once this is set and rings are tight i attach my anti cant level. auto spin drift compensator

Sorry Lewis, I'm not following. How does that compensate for spin drift?

[DenisA]

Oh I think I understand your solution.

[RDavies]

i set my scope up using a string line and a tall taget test my 25 yard zero it printing but still touching the left side of the line. i then wind up to my 1000 yard elevation and have my group print just to the right but still touching the line. once this is set and rings are tight i attach my anti cant level. auto spin drift compensator

Don't you mean, when you wind up to the 1000yd elevation and have your group print to the left of the line, NOT the right of the line?

[DenisA]

That's what I thought Lewis must have been getting at Rod. Sounds like it would present problems when dialling for heavy wind or holding off using the reticle.

[lewis reynolds]

Sorry has been a long drive home from lower light with bad company ha ha

[RDavies]

That's what I thought Lewis must have been getting at Rod. Sounds like it would present problems when dialling for heavy wind or holding off using the reticle.

Lewis was correct. If you set your wind zero at short range you do want it to hit on the LH of the line, both when it is wound down to the 100-300yd setting as well as when you wind up to 1000yd setting on a tall target at short range.
If the bullet is hitting slightly left at short range, it will drift into the centre as it goes down range to give you a proper long range wind zero.
My 6mms which are usually only used out to 600yds are set to hit 1/4 minute left, so be on for 500-600.
My 7mms are set to hit 3-4 clicks left to be right on for 800-900 or 1000

[Tim N]

I suppose the scope could be set up slightly off plumb to be a true zero at all ranges??

[johnk]

Wouldn't that have elevation issues, particularly when a bit of breeze was around?

[RDavies]

Wouldn't that have elevation issues, particularly when a bit of breeze was around?

As well as factoring the higher impacts from right wind and lower impact from left wind. I reckon The FNQ lads have probably got this figured

[DenisA]

Tim and Rod, I thought that's what John and Lewis were both getting at. If you set the cross hair slightly off square position, anticlockwise, then as you clicked up the POI would move to the left of the centre line so that spin drift bring it back toward the centreline at longer ranges. But then the windage wouldn't be on a square plane and nor would the reticule.
If you set this up at the short range, you'd want POI to be closer to the centre at your zero distance and move left on a tall target test as you wind in 28MOA for a .308, wouldn' you?

I think I'm missing the important info that you guys are trying to help me with.

[DenisA]

Rod I think your just talking about setting a short range wind zero so that POI is a little to the left of the crosshair.