Here is the deal.

800 yd target with a 8-15 mph wind from the 6:00 to 7:30.

308 with 175bthp match with good dope. poi was about 2-3 inches higher than poa.

some shooters told me that a tail wind alone will do that.
others think it the tail wind coming off the other berms causing an updraft that do it.

i have read that head wind and tail wind will have little effect on bullet path.
but i think the brems could cause this.
at 900 and 1000 yds it was not as much of a factor.
what do yall think?

Dick

No responses. Hmmmmm. It must be that the holidays are near and everybody is in a peaceful mood. Questions like yours usually start a lot of arguements.

Anyway, 15 mph is 22 fps which is enough to cause some vertical at 800 yards but you wouldn't think it would be as much as 2 - 3 inches. And since you said the error wasn't there at 900 and 1000 yards it is probably caused, at least in part, by the berms. Maybe caused totally by the berms. Or maybe a combination of both wind and berms.

I think you shoot point blank benchrest too, don't you?? I have seen a lot of vertical caused by berms when shooting 100 yards so it would seem that it would be magnified at 800.

Most of the places where I shoot 1000 yards are wide open except for a berm at 600 (for 600 yard matches) but they seldom have head or tail winds.

I'd say, simply don't shoot when the wind is blowing.

Ray

Cheechako

Thanks for the response.

I was shooting at a place called Tiger Valley http://www.tigervalley.com/
in central Texas and the wind blows more than not.

Talk to a friend today that has way more trigger time than I do and he is also one of the ROs at this range and did mention that the 600yd berm is higher (deeper) than the rest due to the way the land rolls.

He also said that the current 30 cal rule of thumb is 20 mph tail wind will cause 1 moa rise in poi.

What I know is that my normal 25 min up was low for poi at 800.
At 1k it might have been as bad but with 36 min up and 10.25 min left it might not have shown as much.