How to see vapor trails??

Discussion in 'General Discussion' started by bigngreen, Apr 26, 2010.

  1. bigngreen

    bigngreen Well-Known Member

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    A little back ground, for the first time this weekend I was able to see consistant traces while my friend was shooting my 270 WSM and being able to see the trace was very helpfull in seeing how the air was moving.
    We were shooting across a draw that had a slow slope on one end and was steep on the target end and we had a 5 MPH wind shoot a 110v max at 3200 FPS for fire forming, range was 756 yrds.
    I cranked on a couple moa for wind and it was way of so I threw on 3.5 more for 5.5 moa and we started spanking the target, I suspected a stronger wind coming down the deeper part of the far draw. But after a few shots I was able to see the traces and I could see the bullet tracking out to the left with only a slight curve till about 2/3 rds out then it curved in hard right over the deepest part of the draw confiming that there was a faster air flow out around 4-500 yrds.

    I would really like to shoot a couple spots to check wind dope for hunting but it would be really like to see the traces because I suspect that they have a heavier spot of air flow.
    What seems to be the trick to first making traces or vapor trails and then seeing them consistantly?
     
  2. Chas1

    Chas1 Well-Known Member

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    I've seen them on occassion but, don't have a clue as to what conditions create them. I'm thinking maybe atmospheric conditons maybe. Hopefully others may know and chime in.
     

  3. Moman

    Moman Well-Known Member

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    Big, we see them on occassion but I'm not exactly sure what causes them. My guess is that it is atmospheric conditions, and my guess is the more humidity the better. Seems like most times the RH has been up pretty high.
     
  4. yobuck

    yobuck Well-Known Member

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    ive been watching them for more years than i am happy about.
    i would assume they are caused by air turbulance or possibly heat and turbulance. we have no problem seeing them and they are an aid in getting on target.
    we always use very good tripod mounted binnoculars for hunting. also a spotter for calling shots when we shoot, using the same type binnocs.
    usually these are made up of twin spotting scopes.
    while the trace, or wash, or vapor trail is helpful, dont rely on that alone. but rather use that as an aid to help see the actual bullet impact.
    at the longer distances you will often lose the trail at its high point and miss the impact unless your watching for both.
    also its common for inexperienced spotters to think your shooting high based on where they last saw the trail.
    of all the tools required for long range hunting, our optics and especially binoculers are hands down the most important.
     
  5. trebark

    trebark Well-Known Member

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    the key to consistently seeing the 'vapor trail' is for the spotter to be positioned directly behind the shooter. Shooting f-class competition at 800, 900 and 1k it's a regular occurence to set up next to the shooter - can't see the trail. Move directly behind the shooter and instantly you're picking up the trail.

    Previous comment is correct that you will typically be able to see the trail up until it's highest point. Once it begins to drop, you need to move quickly to the potential point of impact and watch for that.
     
  6. Chas1

    Chas1 Well-Known Member

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    so will you more often that not see them if your directly behind the shooter or does atmospheric conditions play a part also?
     
  7. bigngreen

    bigngreen Well-Known Member

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    I've seen them in BPCR matches and shooting and you can call the shots by the vapor trail if they are good.
    I've been thinking that humidity and possibly sun angle helps.
    I have noticed that if you see them while spotting from the side that if you move directly behind the shooter they do stand out more and you can track better with more accurate reads relative to the shooters position.
    I would really like to predict good days or times to shoot so that my odds are good to have them.
     
  8. winmag

    winmag Well-Known Member

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    I see them most often while spotting from behind the shooter with a spotting scope 1/4 turn out of focus. Realy cool for seeing wind effect on bullets, but like stated multiple times already, the spotter tends to ''call the shot high'' at poi because its very hard to train yourself to take your eyes off of what they were focused on seeing, and swich to the target in time to see and focus on impact.
     
  9. yobuck

    yobuck Well-Known Member

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    directly behind or slightly off is best. especially if you want to watch it all the way. other than that you might catch a glimpse of it if you know what and where to look. a single spotting scope will work but binoculars are better. conditions dont matter much, except for very windy days.
     
  10. trebark

    trebark Well-Known Member

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    while i'm sure atmospheric conditions have something to do with it, I've never really noticed. I pretty much get in-line behind the shooter and watch the bullets fly.

    Best atmosphere for spotting trails....rain!
     
  11. bigngreen

    bigngreen Well-Known Member

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    So you think a cool humid morning or after the sun has gotten up and we start to get mirage, say mid morning. Or do you go for a later evening after it cools down?

    One cool thing that I figured out, is with Loadbase 3.0 I used the multiple wind zones and set the first zone out to 400yrds for a 5 mph wind and then I set from 400 to 800 for 12 mph and it was within a 10th of an inch for windage and elevation. I really think if I can figure out how to get an accurate wind dope I can predict more accurately what is happening in the draws and canyons I shoot.
     
  12. Chas1

    Chas1 Well-Known Member

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    I'm kinda thinking humidity has something to do with it. My guess is it's like the vapor you see sometimes produced by fighter jets taking a hard g-force turn...I think the air get compressed and the humidity starts to get squeezed into vapor...maybe bullets cause the same thing sort of. I don't know just speculating. Maybe someone will chime in with the scientific answer.
     
  13. royinidaho

    royinidaho Writers Guild

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    Atmospheric conditions are key to how well the bullet trail is observed.

    It takes a bit of practice to recognize what one is seeing. My first observation was a ripple effect that affected the entire field of view of my scope. I was beside the shooter who had commented on the trail from my shots.

    Once I learned what/how to watch I could call the shot well before impact. It seemed like everything went into slow motion. He was shooting a 270 Win a long ways in a decent wind. The drift of the bullet was significant. It was easy to observe from about 1/3 rd of bullet travel all the way to the target.

    I let him shoot my rifle, 270 AM, so I could observe the differences in cartridge performance. The difference was significant to say the least.

    Observing large caliber lead cast bullets traveling away from the sun is impressive. The shiny base is clearly observable all the way to the 200 meter rams.:D
     
  14. Chas1

    Chas1 Well-Known Member

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    Roy, tell us the what and how.