Discussion in 'Technical Articles - Discussion' started by ADMIN, Oct 6, 2007.

Reading The Wind

  1. ADMIN

    ADMIN Administrator

    Messages:
    1,145
    Joined:
    Mar 6, 2008
    This is a thread for discussion of the article, Reading The Wind, by Shawn Carlock. Here you can ask questions or make comments about the article.

    The author will have this thread automatically notify him of posts so that he can join the discussion.
     
  2. Ian M

    Ian M Well-Known Member

    Messages:
    2,410
    Joined:
    May 3, 2001
    Shawn,
    Great info and a very nice read. We just experienced the elevation component of high winds a couple of days ago. Guys thought they had some bad ammo because the elevation was moving about so much. We were shooting along a big coullee and across a couple of smaller ones that the wind was moving upwards out of the big coullee (left to right from 8 to 10 o'clock). Gusts to about 17-19mph, down to 11. Distance was 1000 yards and we were amazed at the elevation effect.
    Thanks Shawn, enjoyed the info.
     

  3. Ernie

    Ernie SPONSOR

    Messages:
    2,844
    Joined:
    Jun 18, 2007
    Shawn,
    Thanks for all the good insights and info. To top it all off, you made it easy to understand to boot.
     
  4. royinidaho

    royinidaho Writers Guild

    Messages:
    8,853
    Joined:
    Jan 20, 2004
    Shawn,

    Not about wind but......This may go along with your setting up for the LR shot but was prompted by the pic of your dad setting up for the across the canyon shot. Besides I've found that if the set up isn't correct the wind doesn't mean squat at least for me.:eek:

    I noticed slop of the hill. The bipod at least has the opportunity to be consistent with the slope of the ground. Do you do anything to adjust (dig/level/extend leg/etc)?

    I know that you are quite experienced shooting LR , as evidenced by your article's charts and your previous successes, whereas I'm pretty much a greenie. We'll shortly see if any of your experience rubbed off.;)
     
  5. Shawn Carlock

    Shawn Carlock Sponsor

    Messages:
    1,897
    Joined:
    Jun 11, 2007
    Roy,

    I use a anti cant level on the scope to note how level the rifle is. I use a Harris "S" series bipod with a Pod-Loc. When getting into position I use the bipod to correct small cants then loc in place with the pod loc. If the cant is huge I adjust a leg. I do this before getting behind the rifle.
     
  6. lorvan

    lorvan Well-Known Member

    Messages:
    59
    Joined:
    Oct 7, 2005
    Software

    Shawn,

    which type of ballistic software do you use?
    Is accurate?

    Lorenzo
     
  7. john powers

    john powers Member

    Messages:
    12
    Joined:
    Sep 7, 2007
    Reading the wind

    Shawn Did you talk to Tom this week and write this for us ?????Ha Ha we went up to 6000ft to do some practice last weekend and had the updraft effect our 800yd shots 2.5 moa less then our charts called out. We had about a 7mile per hour wind coming straight up the canyon at us and we were shooting 20 degrees downhill. I had no idea up draft would effect our moa that mutch it seems to be about the same as windage ,,,anyway Thanks Good Hunting,,,John Powers:eek::cool:
     
  8. Shawn Carlock

    Shawn Carlock Sponsor

    Messages:
    1,897
    Joined:
    Jun 11, 2007
    Lorenzo,

    I use the Nightforce Exbal program.
     
  9. Shawn Carlock

    Shawn Carlock Sponsor

    Messages:
    1,897
    Joined:
    Jun 11, 2007
    No it just applies to everyone who hunts in canyon country. Most people just never think about waht happens when the wind blows over certain terrain features. Good luck hunting.
     
  10. Ari

    Ari Member

    Messages:
    9
    Joined:
    Apr 10, 2006
    Hi Shawn,
    I have a question about your article:

    "When shooting a righthand twist barreled rifle, a left to right wind will cause the bullet to impact to the right and slightly low. The same barrel in a right to left wind will cause an impact to the left and slightly high."

    could you explain me why this happen?

    Best regards.

    Ari.
     
  11. Shawn Carlock

    Shawn Carlock Sponsor

    Messages:
    1,897
    Joined:
    Jun 11, 2007
    There is a named effect for this action but the name escapes me right now. By belief is this, when a bullet is engraved by the rifle barrel it makes places for the air to grab the bullet and effect it. With this in mind spinning into a wind causes it to strike slightly low and spinning with it makes it strike slightly high. This effect is very small but does exist. I have noticed that poly rifling and 5r rifling engrave the bullet less and tend to not have an abrupt edge in the engraving. Bullets fired through these barrels show less of this effect in the same conditions. Reguardless of why, it does occur. it is very noticable with more accurate smaller caliber rifles like a 6mm BR benchrest rifle that shoots "in the 1's" it is very noticable. The accuracy of this rifle and size of its bullets make the .100-.150" elevation change of this effect very noticable. If you are shooting a 1/2" .338 cal rifle it is tougher to see, but does exist. Hope this helps.
     
  12. gamedog

    gamedog Well-Known Member

    Messages:
    591
    Joined:
    Aug 16, 2007
    Great article Shawn. One question . This weekend I missed a shot at a coyote @ 288 yards strait across a draw. I'm shooting 180 gr TSX"S @ 3200 fps. I had a solid 20 mph headwind and thought that would drop the bullet a bit. So I aimed at the top of his back. Do you believe the headwind lifted the bullet or dropped it? I understand cross winds , but this has be baffled.
     
  13. Shawn Carlock

    Shawn Carlock Sponsor

    Messages:
    1,897
    Joined:
    Jun 11, 2007
    If you had a 20 headwind shooting across a draw you probably shot over it but it is hard to say for sure without seeing the conditions and location of the shot.
     
  14. Ari

    Ari Member

    Messages:
    9
    Joined:
    Apr 10, 2006
    Hi again Shawn,

    It´s possible that the name of this effect would be "Magnuss effect"?
    May be that this effect works in the other way?:

    "When shooting a righthand twist barreled rifle, a left to right wind will cause the bullet to impact to the right and slightly HIGH. The same barrel in a right to left wind will cause an impact to the left and slightly LOW."

    Best regards.

    Ari.