LR, wind, and mountains

[BrentM]

Another lesson over the weekend. I was hunting wolves and cats and spotted a shootable cat. It's a long story so I will cut to the point-

600 yard shot. Backside of mountain and back side of wind direction. The wind mainly had been, as facing down the finger/ravine, blowing left to right and it was gentle (3-4 mph). During my hold and target area observation it appeared the wind was NULL in this protected area. ?? Sent it, the hit was 6-9 inches left. Cat was slightly angled toward me. When I got to the area I noticed the wind was now right to left and coming up the ravine. Should have held 1 moa right, from my new calculations.

Later I shot uphill at 900 yards. When I took the wind reading at my spot it was right around 6mph (2.6 moa) but a little gusty. Wind was right to left. As I hiked up the slope I was trying to take note of the wind but it was minimal in most spots, until I got close to the target. At the strongest point it was 8mph. My impact was vertically good, horizontally it was left 9-12 inches. I needed 3.4 moa according my program based on 8mph vs the 6 mph I input. The strike and the new calculation look about right. When I got the saddle, above this test shot, the wind was 12. Crap.

I am not new to the mountains of course but reading wind for hunting game seems significantly different than shooting. I have noticed all sorts of weird things with the wind lately such as the way it builds up, holds it's breath, then lets it go. I call it flushing. I see rivers do the same thing behind a rock.

Is there a good site that helps describe wind flow and mountain terrain? I am feeling pretty inadequate and need a better wind reading education.

 

[mtnwrunner]

Brent, man, that is an awesome take and congrats on working through it.

Randy

 

[Alfred Crouch]

Can't help you on the wind; but, very nice lookiing kitty.

 

[BrentM]

Thanks guys. I know I need to field test and learn but I can not get reloading supplies here in Boise and don't have enough left to do much practical shooting. I tend to do well with in-field training and reading or researching. I am finding there may be a pattern to this mountain wind currents and am looking for any advise I can get.

 

[Boman]

I cant help with wind but thats a great cat. Im jealous, I hope to do that someday.

There is a video from best of the west about wind doping, that might help. I havent seen it though. Good luck

 

[BrentM]

Thanks. We have hound guys that will run for us anytime but my buddy I prefer spot and stalk. It is tough, cats are super sneaky, and can hide with some mad skills. I have only wanted to shoot one other cat in the past 20 I have spotted. The only reason I didn't shoot it was due to not knowing if the female quota had been met yet. It was much larger than this one so I assumed it was a male, but passed on the shot. I did get pictures though. : )

This cat seemed much larger at the time I was estimating size, not very good at that for sure, but it seemed like a shooter and well, it all managed to work out. Whew!

OK, about wind: What I am observing is back drafts and low pressure areas. I call these hides. Hides is the area of the terrain the wind is confused and trying to find balance. If you look at wind at the very top of a mountain it curls over the lip and tumbles into self, like a cartwheel. Further down the mountain there is back draft area where the wind is actually going up the mountain, then the transition or hide area, then the area where the wind is going back down again.

What I have observed is a few different wind directions in a 1000 yard plus target range. For example, near the top the wind may be generally blowing down and to one side, the next area it is coming back up, the hide area is confused and swirling, the bottom is coming back up the mountain etc. I also notice the surge, calm, and then flush. The cycle starts over again. To complicate this even further it depends if the target is one side or the other of the down range ravine.

On front sides of the terrain to the wind direction calculating windage seems pretty straight forward and consistent. However, it is kind of rare you have a target that stays within that terrain feature. Another fun one I encountered Sunday was a down draft on side of deep ravine and I noticed an updraft on the other side. I have no clue what is was doing the middle. I assume the hokie pokie.

 

[Alfred Crouch]

Brent, What rifle and caliber were you shooting?

 

[BrentM]

6.5-284.

 

[royinidaho]

Brent,

I'm with you on the wind thing. I have several "hides" from which I regularly shoot. Distances reach beyond 1100 yards. Each one is different terrain.

After two years of shooting at hide #1, I generally multiply my wind correction by 1.5 to 1.8. This gets the first shoot closer than using the measured wind at the hide without the correction.

The wind is usually blowing from left to right with velocities typical for Idaho. Even with dead still wind at the hide I have to compensate at least a min or min and a half @ 1200 to hit the mark. More practice coming this spring (whenever that is) and summer.

This is across a large canyon that is not quite parallel to wind direction. I have passed several shots at elk there due to lousy wind conditions.

I tried a spotting shot once but learned that our local elk are well educated to what a bullet impact is.

The other two hides are more open with only rolling terrain but at a pretty decent down angle. We'll see what spring and summer brings at these location.

It took me quite awhile to learn to not over focus on the reticle and target. When my windage impact was way unexpected I learned to observe everything going on in the field of view. It turns out, for me at least, good optics is more important for observing grass movement than observing game.

Also I don't think one has to shoot all that much to improve. When attempting to make EVERY practice shot hit the POA spot on I might get 4 shots off in 30-45 minutes. It takes a lot of study and concentrated glassing to learn which range has the dominant wind affect. I've learned that it is not always the closest wind that has the largest affect. Usually but not always.

BTW, nice cat and great shooting.

 

[westcliffe01]

You might try corresponding with Bryan Litz, young guy in MI who wrote "applied ballistics for long range shooting". He apparently has a portable wind meter setup where he can have several meters to get wind data across a given area. I believe each meter transmits wirelessly. It would be cool if a system of such meters could be setup to get a feel for how the wind behaves in a particular area that one is expecting to hunt.

 

[BrentM]

Good info and thanks for responding. I am very new to LR and spent the past 30 years working on my archery skills. There is always room for improvement and this addicting challenge is showing me just how much.

I will continue to use my glass to help me identify wind movement as you do. I tend to do a lot of glassing with my binos and spotting scope and find myself more and more watching vegetation movement. Kind of weird telling people I am watching the wind.

 

[bigngreen]

Shooting in the mountains is about as fun and challenging as it gets, we spend most of the year seeking out challenging locations to shoot. In my area the prevailing wind is the key factor, to figuring out how the wind moves through the area, once you find the key in your area I think then a guy can almost visualize the air moving like water over the region. Getting out in a snow storm that you can watch the air compress over saddles or create huge up drafts and swirls coming up the back side of a large draw definitely gives you a real good look at what's happening. The crappier the weather the funner the shooting

I get almost no indicator of vegetation here but you hear the wind change in the upper flow that is in the tops of the pines even if you can't feel it you can hear it in a lot of the terrain I shoot.

 

[BrentM]

Another thing I found interesting is the ground level wind vs bullet path wind. It makes since to watch the tops of trees for wind indicators. For example, I held me kestrel at shoulder level and then reached way up, then handed it to my 6'4" buddy. The difference from my normal reading to level to his stretched out was 3 mph. This reading was on a open finger up from a plateau.