Range Report Wild Day At Range Shooting Into 35-40 MPH Headwind

[samnev]

Also pasted on Bolt Action Thread,

Went to the range yesterday, 13 mile one way trip, Wind was 5-10 mph when I left home. When I got to the range the wind had picked up to a steady 35-40 mph head wind the temp was 43 degrees. But my brother and I decided to try shooting any way. I was shooting my 308 AIAW which usually shoots bug holes @ 100 yards. My brother was shooting his 308 Remington SPS Tactical. both of us were shooting 168 SMK's @ 2700 fps. The first shot for both of us was dead center on our 1st 1" diamond we were shooting at the next 4 shoots for both of us were progressively lower. The lowest for me was about 3" with the 4 shots almost a perfect vertical string. The same with my brothers next four shots with some horizontal spreading as well. His vertical dispersion was about 4". Both rifles are capable of shooting under 0.5 moa on a good day and my AIAW has never shot group much over 1" and that was when i first got it. My brothers rifle shoots largest group was about 1.5".
Repeated with a 2nd 5 shot group, same results. Pack up and went home. I expected the groups would open up but nothing like we experienced Anyone out there have an explanation on why the wind had such a huge effect on the 168 SMK's. If I was shooting at 500 yards I could understand it, not at 100 yards. By the way just to make sure when I got home checked the scope rings and base, Everything was tight.

I would really appreciate it if someone with a deeper knowledge of exterior ballistics has an answer as to why the large vertical dispersion took place on both our attempted groups.

Thanks in advance.
Sam

 

[RTH1800]

Wind behind you? That velocity of wind could easily cause vertical stringing.

 

[samnev]

Wind behind you? That velocity of wind could easily cause vertical stringing.

The wind was directly in my face (head wind) with an occasional gust on a slight diagonal towards the bench I was shooting from. The wind was coming down a steep hill and the trees on the hill were moving a lot. The range itself is only 200 yards with the berm in back of the 200 yard line in front of the steep hill. No debris was blowing in my face.

 

[RTH1800]

That will string shots as well. No problems with rifles or ammo.

 

[Powermac]

Gusting winds will have to take responsibility for your groups opening up.
Also coming down the hill through obstacles it will not be equal in force.
More wind just makes shooting harder and is a welcome challenge.
Had more then 30 mph winds for most of the last 2 months up here so i know the conditions all to well.

 

[samnev]

I took the AIAW back to the range Wednesday. Winds very light and variable. Temp 65. Back to shooting 5 shot 100 groups < 0.5 moa. My best group was just over 0.3 moa. So I guess the wind was the major problem.
Thanks for all the replies.