Advanced Marksmanship Wind Drift Chart (6.5mm & SWFA SS-HD)

[Das Capitolin]

I need a wind drift chart for my 260 Remington/24x SWFA SS-HD long-range setup, and would like to collect as much data beforehand as possible to get a head start.

I expect that the bullet, powder charge, barrel length, etc all play into windage, but I'm curious if there's a general 6.5mm wind drift chart out there somewhere to offer some initial guidance. Beyond that, my next feat is converting it into useful milrad data for the SWFA SS-HD scope.

Thank you in advance for the help.

 

[Lucks]

Re: Wind Drift Chart (6.5mm & SWFA SS-HD)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Das Capitolin</div><div class="ubbcode-body">I expect that the bullet, powder charge, barrel length, etc all play into windage, </div></div>Correct...this will matter more than caliber and the scope you are using!

You'll eventually need to determine your bullets weight, BC (Ballistic coefficient), and velocity.

Here is a little cheat sheet I carry with me at matches for my .260 (142gr SMK's at ~2800fps). I don't use it much anymore but this may help get you started. The ranges are in yards and the three columns are for full value (90degree) 5mph wind,10mph wind, 15mph winds. The drift is in <span style="font-weight: bold">MILS</span>. If you study the chart you can see that a pretty linear pattern develops that will give you a good guess at the correction for inbetween wind speeds. What I mean is that the 10mph correction is basically just the 5mph doubled. So, a 2 to 3 mph wind would roughly be the 5mph wind divided by 2,etc,etc.

 

[Das Capitolin]

Re: Wind Drift Chart (6.5mm & SWFA SS-HD)

Thank you! This should help me get started.

 

[Swift]

Re: Wind Drift Chart (6.5mm & SWFA SS-HD)

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Lucks</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Das Capitolin</div><div class="ubbcode-body">I expect that the bullet, powder charge, barrel length, etc all play into windage, </div></div>Correct...this will matter more than caliber and the scope you are using!

You'll eventually need to determine you bullets weight, BC (Ballistic coefficient), and velocity.

Here is a little cheat sheet I carry with me at matches for my .260 (142gr SMK's at ~2800fps). I don't use it much anymore but this may help get you started. The ranges are in yards and the three columns are for full value (90degree) 5mph wind,10mph wind, 15mph winds. The drift is in <span style="font-weight: bold">MILS</span>. If you study the chart you can see that a pretty linear pattern develops that will give you a good guess at the correction for inbetween wind speeds. What I mean is that the 10mph correction is basically just the 5mph doubled. So, a 2 to 3 mph wind would be the 5mph wind divided by 2,etc,etc.

</div></div>

I love seeing that +/- 2mils all the way to 1000. Really does feel like cheating sometimes