Desert Windage Estimation?

sigcurious · February 19, 2013, 09:06 PM

What kind of techniques do you all use to estimate wind speed when natural indicators are few and far between? The small leaves and stiff branches of the desert shrubs where I shoot just sort of vibrate/twitch in the wind.

oryx · February 19, 2013, 09:52 PM

Use your optics to read mirage. This is the affect of heat distorting the light as viewed through your scope. Similar to seating the heat rise off an asphalt road in the summer.

You can adjust your focus point about 2/3rds of the way to your target and see the mirage and the effects of the wind on it. Tons of information on reading mirage, but the best advice I can give you is practice reading the mirage and notice the affect it has on your bullet impact on your target. You will see the mirage move left to right,right to left, boil straight up (no wind), or at angles to either side. Each represents a varying degree of wind condition. With practice you can estimate windage fairly well based off of mirage

oryx · February 19, 2013, 09:58 PM

Here is an article that can explain in more detail

http://southtexasshooting.org/multim...xt/mirage.html

allaroundhunter · February 19, 2013, 11:48 PM

Without flags or vegetation, mirage is your best bet. It is even good to use it when you do have some of those other indicators.

sigcurious · February 20, 2013, 01:12 AM

Thanks for the link, hopefully the winter storm doesn't cool things down too much tomorrow and I make it out to the range to try it out.

Old Grump · February 20, 2013, 01:41 PM

Did a lot of long range shooting in New Mexico, Arizona and Texas and got pretty good after comparatively little time in reading mirages. I had range flags to confirm my guesses but after awhile I didn't need the flags anymore. I did learn that the wind up next to me and mid range was more important than the wind down at the target. Seemed counter intuitive at the time till somebody pointed out to me that the longer the time the wind is on the bullet the more affect it has. That would be the first 2/3 of the flight path of the bullet.

The Texas link on mirage was pretty good so I will leave my link off. It wouldn't really add much more.

Bart B. · February 20, 2013, 06:45 PM

Sigcurious, if you can focus your rifle scope about 2/3 the way to the target, it's easy to see the mirage wrinkling across your field of view as mentioned earlier. Pay close attention to that between the target and several feet above it as that's where the bullet's gonna fly.

Old Grump, your info on near vs far winds' effect on drift are pretty accurate.

In my calculations with ballistic programs, it shows the wind in the first 1/3 of target range has more effect than the last third.

sigcurious · February 20, 2013, 07:30 PM

Quote:

Sigcurious, if you can focus your rifle scope about 2/3 the way to the target, it's easy to see the mirage wrinkling across your field of view as mentioned earlier. Pay close attention to that between the target and several feet above it as that's where the bullet's gonna fly.

I've been following your focus vs parallax discussion. Which basically has me more confused. The stuff I had read previous synced up with what timelinex(sp?) had said, but then the more you two talked, the more it seemed perhaps you were both describing the same thing from different approaches/terminology.

With that in mind... my scope has a parallax adjustment and an eye piece focus. I am assuming you guys mean set my parallax adjustment to 66 yards if I'm shooting at 100yards, or 200 at 300.

Thanks again for the help guys.

Bart B. · February 20, 2013, 07:52 PM

sigcurious, for reading the wind for a 100 yard target, focus your scope at 66.66666666666666666667 yards down range. The more precicely you focus your scope, the better you'll be able to see 2/1,000,000ths of a mile an hour wind change.

That's what an Olympic smallbore champion told me, but my scope's not graduated that fine.

So get yours pretty close to that and you'll do just fine. Use the range focus (parallax) to do that after you've got the scope's eyepiece focused correctly for your aiming eye such that the reticule looks as sharp as a surgeon's scalpel.

oryx · February 21, 2013, 08:43 PM

Remember, you are focusing your scope at 2/3 the distance to optimally view the mirage, not the target. Study the mirage to look for patterns of the Wind letting off or surging. If it is fairly consistent, take your time and focus your scope back to the target for the shot.

What some of us here are describing is a situation for highpower competition where we are focusing our "scope" (read spotting scope) to view mirage and monitor wind conditions and then fire the shot using iron sights. The scope is set up in this situation right next to your rifle in a prone position and we can switch back and forth quite quickly. If you are using a scoped rifle, you would focus your scope to optimally view mirage and then refocus for a shot.

February 19, 2013, 09:06 PM	#1
sigcurious Senior Member Join Date: May 25, 2011 Posts: 1,755	Desert Windage Estimation? What kind of techniques do you all use to estimate wind speed when natural indicators are few and far between? The small leaves and stiff branches of the desert shrubs where I shoot just sort of vibrate/twitch in the wind.

February 20, 2013, 01:41 PM	#6
Old Grump Member in memoriam Join Date: April 9, 2009 Location: Blue River Wisconsin, in Posts: 3,144	Did a lot of long range shooting in New Mexico, Arizona and Texas and got pretty good after comparatively little time in reading mirages. I had range flags to confirm my guesses but after awhile I didn't need the flags anymore. I did learn that the wind up next to me and mid range was more important than the wind down at the target. Seemed counter intuitive at the time till somebody pointed out to me that the longer the time the wind is on the bullet the more affect it has. That would be the first 2/3 of the flight path of the bullet. The Texas link on mirage was pretty good so I will leave my link off. It wouldn't really add much more. __________________ Good intentions will always be pleaded for any assumption of power. The Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern will, but they mean to govern. They promise to be good masters, but they mean to be masters. --Daniel Webster--

February 19, 2013, 09:52 PM	#2
oryx Senior Member Join Date: December 26, 2008 Posts: 142	Use your optics to read mirage. This is the affect of heat distorting the light as viewed through your scope. Similar to seating the heat rise off an asphalt road in the summer. You can adjust your focus point about 2/3rds of the way to your target and see the mirage and the effects of the wind on it. Tons of information on reading mirage, but the best advice I can give you is practice reading the mirage and notice the affect it has on your bullet impact on your target. You will see the mirage move left to right,right to left, boil straight up (no wind), or at angles to either side. Each represents a varying degree of wind condition. With practice you can estimate windage fairly well based off of mirage

February 19, 2013, 09:58 PM	#3
oryx Senior Member Join Date: December 26, 2008 Posts: 142	Here is an article that can explain in more detail http://southtexasshooting.org/multim...xt/mirage.html

February 19, 2013, 11:48 PM	#4
allaroundhunter Senior Member Join Date: May 6, 2012 Location: Southeast Texas Posts: 1,670	Without flags or vegetation, mirage is your best bet. It is even good to use it when you do have some of those other indicators.

February 20, 2013, 01:12 AM	#5
sigcurious Senior Member Join Date: May 25, 2011 Posts: 1,755	Thanks for the link, hopefully the winter storm doesn't cool things down too much tomorrow and I make it out to the range to try it out.

February 20, 2013, 06:45 PM	#7
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	Sigcurious, if you can focus your rifle scope about 2/3 the way to the target, it's easy to see the mirage wrinkling across your field of view as mentioned earlier. Pay close attention to that between the target and several feet above it as that's where the bullet's gonna fly. Old Grump, your info on near vs far winds' effect on drift are pretty accurate. In my calculations with ballistic programs, it shows the wind in the first 1/3 of target range has more effect than the last third.

February 20, 2013, 07:52 PM	#9
Bart B. Senior Member Join Date: February 15, 2009 Posts: 8,927	sigcurious, for reading the wind for a 100 yard target, focus your scope at 66.66666666666666666667 yards down range. The more precicely you focus your scope, the better you'll be able to see 2/1,000,000ths of a mile an hour wind change. That's what an Olympic smallbore champion told me, but my scope's not graduated that fine. So get yours pretty close to that and you'll do just fine. Use the range focus (parallax) to do that after you've got the scope's eyepiece focused correctly for your aiming eye such that the reticule looks as sharp as a surgeon's scalpel.

February 21, 2013, 08:43 PM	#10
oryx Senior Member Join Date: December 26, 2008 Posts: 142	Remember, you are focusing your scope at 2/3 the distance to optimally view the mirage, not the target. Study the mirage to look for patterns of the Wind letting off or surging. If it is fairly consistent, take your time and focus your scope back to the target for the shot. What some of us here are describing is a situation for highpower competition where we are focusing our "scope" (read spotting scope) to view mirage and monitor wind conditions and then fire the shot using iron sights. The scope is set up in this situation right next to your rifle in a prone position and we can switch back and forth quite quickly. If you are using a scoped rifle, you would focus your scope to optimally view mirage and then refocus for a shot.