up drafts and misses

405win · #1 11-25-2011, 09:41 PM

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 · #2 11-25-2011, 10:02 PM

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 · #3 11-25-2011, 10:03 PM

Quote:

Originally Posted by 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.

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 · #4 11-25-2011, 10:53 PM

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 · #5 11-25-2011, 11:02 PM

Quote:

Originally Posted by 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.

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 · #6 11-26-2011, 12:14 AM

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 · #7 11-26-2011, 12:41 AM

Quote:

Originally Posted by 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.

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.