up drafts and misses

[405win]

Is there such a thing? I have experienced and witness several high misses at the 500 yard mark across canyons this year and wonder what gives. I have practiced to 600 yards and am (was) extremely confident at that and shorter ranges. The misses involve two different guns and shooters and no more than a 10 degree change in target elevation. Shots that weren't across canyons were spot on.
The high misses appeared to be around 8 to 10 inches high but I can't be sure.
I have heard of up and down drafts, but how do you allow for them or identify them? or is this even the problem?
Your imput and experience is requested.

 

[RDM416]

Yes, up or down drafts can be a problem. I experienced this a few years ago when shooting at an elk across a canyon at around 800 yards. I missed over the elk several times. It was not until later that I figured out that I had an updraft due to a sharply sloping canyon floor and a 12 MPH crosswind blowing up the canyon.

How to read and compensate for it? Intuition based on experience maybe. The best advice I got was don't try LR shots in those situations where you have a strong wind wind that could cause such an updraft.

"A mans got to know his limitations."
Words of wisdom from Dirty Harry.

 

[WildRose]

Is there such a thing? I have experienced and witness several high misses at the 500 yard mark across canyons this year and wonder what gives. I have practiced to 600 yards and am (was) extremely confident at that and shorter ranges. The misses involve two different guns and shooters and no more than a 10 degree change in target elevation. Shots that weren't across canyons were spot on.
The high misses appeared to be around 8 to 10 inches high but I can't be sure.
I have heard of up and down drafts, but how do you allow for them or identify them? or is this even the problem?
Your imput and experience is requested.

Yes, bot up and down drafts can have a significant effect on trajectory.

That is why shooting across canyons or down into valleys from a high point can be considerably more challenging than shooting across relatively level ground.

 

[405win]

Thanks guys for the reply.
Finding a place to practice under these conditions will likely be as hard as actually shooting in these conditions.
I'm still trying to make sense of the whole thing.

 

[WildRose]

Thanks guys for the reply.
Finding a place to practice under these conditions will likely be as hard as actually shooting in these conditions.
I'm still trying to make sense of the whole thing.

About the only way to practice it is to practice in canyons.

What you can do to help yourself is to observe for visual cues as to what the wind is doing, by which way the trees, grass, etc. are doing on the slopes and in the bottoms.

For a lot of people long range shooting is a matter of mastering various pieces of technology, but the technology cannot account for things such as up/down drafts and changes in wind direction from where you are, mid flight and at the target which can be significantly different with elevation changes and canyons.

If you are shooting across a left to right canyon that's snakey, and also along a draw that feeds to it, the wind up the draw on your side, and along the draw on the far side can be significantly different to the extent that you may be shooting into a head wind, that is a cross wind through the canyon, that is then a tail wind up the draw on the far side because the cross canyon wind is feeding up the slopes of both draws.

The technology you can carry into the field with you simply cannot deal with those variables.

 

[405win]

What you discribe is very similar to one scenario we encountered. Head wind on our side, dead at the bottom (no idea what the wind was like in bullet path), and something of a tailwind on the far side.
The wind could have changed in the canyon bottom considering the length of time it took us to get there.
I imagine wind currents are different in nov. than say june. So is practicing in june going to help me.
The snow will be too deep (very soon) to get to these canyons for practice.
Thanks wildRose for the info.
I'm learning, albeit slowly.

 

[WildRose]

What you discribe is very similar to one scenario we encountered. Head wind on our side, dead at the bottom (no idea what the wind was like in bullet path), and something of a tailwind on the far side.
The wind could have changed in the canyon bottom considering the length of time it took us to get there.
I imagine wind currents are different in nov. than say june. So is practicing in june going to help me.
The snow will be too deep (very soon) to get to these canyons for practice.
Thanks wildRose for the info.
I'm learning, albeit slowly.

In all likelihood the winds over the summer will even be tougher since you get a whole lot of rising air in the morning as things warm up and sinking air in the evening as things cool down.

While technology helps it will never replace the "art of shooting". Just look at all the threads here where people say "I did everything right and still missed, what went wrong?"... .

Even the best weather stations and ballistic programs have their limitations in that they can only give output for where you are shooting from, and the shooting solution will never be more accurate than the data put into the computer.

 

[Len Backus]

One of the most important things I learned in Shawn Carlock's Defensive Edge Long Range Shooting Class last summer was how to identify updrafts that can affect your vertical POI.

I still have this image in my head of a Christmas tree with arms, and the arms are slowly waving up and down, up and down. You see, a tree sways side to side when there is a cross wind. The same tree sways up and down when there is an updraft. Quantifying the change in POI is really tough, though. Now that I understand the basics of updrafts, I'd have to spend a LOT of time out west in canyons to really learn how to do that.

Hey, that sounds like another great excuse for another trip out west. Yippee!

I'll be publishing a review of his class next month. When you consider how much time, effort and $ we all spend on this terribly addicting sport called Long Range Hunting -- you owe it to yourself to take a long range shooting/hunting class to make yourself able to reach the next level in your abilities.

That would be a great Christmas present to yourself.

 

[trueblue]

This type of scenario is even tougher to prctice for us flatlanders.

 

[405win]

I am blessed in that forest service land is just a mile away but finding the canyons where these conditons play out is a little further.
The idea of a shooting school sounds like fun so long as I don't embarrass myself too badly.

Thanks RDM for your story, I don't feel like I'm the only one to have this problem. I sat in hunting camp trying to figure out what went wrong, and only when I got home was I starting to put pieces together.

I really appreciate having a place like longrangehunting.com to ask questions knowing I'll get help from people who know.
Thanks guys.

 

[Shawn Carlock]

405 Win,


If you review the "Reading The Wind" article I wrote there is some solid info in it about wind over terrain features. This kind of shooting is a key component of long range canyon shooting and being able to read it and correct it is what really puts you a step up. Simply put, when you practice in these conditions and have a miss (usually high) look for the wind direction and terrain feature that is causing the lift or sometimes drop. Once you see these wind/terrain features working in concert togehter you will start to notice them before you shoot and start correcting for them. Unfortunatly this is one of those areas that just takes time and practice to learn. I rarely shoot in good conditions anymore to practice, take a good windy day and go see how these features effect your bullets flight.

 

[Buffalobob]

If you watch the birds flying you will see some of them use these natural escalators to gain altitude.

 

[ken snyder]

Around here that's all we have to shoot over. Sometimes the wind will push a bullet right back on target and any wind correction will be the wrong thing to do. Measuring the wind from where a guy is shooting from is pretty much the easiest way to guarantee a miss. Avoid using flat land tactics and skills because they absolutely will not work in Hillbilly country. There is a place here in Oregon called Big k I havent seen it with my own eyes yet but it is my understanding that their instructors specialize in this type of shooting. There is so much difference between flatlander shooting an ravine shooting that unless you live in an area that thats all their is, you will never be able to pick it up without instruction because all the tools of learning are missing!

 

[secondofangle]

We just began learning of this in WVa with long range varmint hunting and gong shooting over a canyon. At 1100 yards my 300 RUM should have Needed 21.25 MOA up and 1.5 of wind based on the wind at the shooting position. That put me 1-2 MOA high and the actual wind correction needed was 3-4 MOA. It's incredibly challenging shooting across those hollows. I kept going back to my ballistics program to try to figure out why the elevation was off and where the error was. There was no error. There was an imperceptible (but significant) vertical wind across that hollow and it changed by the second.