wind at 200 yards?

U

uchi

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i was shooting my new handloads the other day and there was some cross wind. shooting 178gr hornady amax with the max recommended powder coming out at i believe about 2700 fps as per the book. shooting at a range with sides as high as the back stop, id say probably about 25-30 feet. someone who shoots at silverdale could confirm this maybe.

i noticed my shots at 200 were all over the place, some of them hit dead center, some were as far as almost 3 inches off. at first i blamed this on the hand loads as my last batch being a bit lighter shot a little over 1/2 moa at 100. so with winds making their way into the path of the bullet, how much would it affect the bullet out to 200 yards?

this was this past saturday, i dont know how strong the winds were but they were present.
 
Put flags up and see how they move.

Having berms on the sides can make winds even worse cause you can created turbulence.

Think big Hawaiian wave crashing into the shore. Air does tumble very nicely over lips and hills. That can create all sorts of nonsense on your target.

Bullets will never be immune to wind. Know what its affects are.

Jerry
 
10 mph is possible, the winds picked up a little bit along with a small amount of snow. ill try loading some more like this and some lighter loads and get a flag out there for next time. thanks for the help guys.
i noticed a few of the shots were dead on to where i wanted them to be and some werent so im hoping the wind played its part the other day and it wasnt completely my loads.
 
uchi said:
10 mph is possible, the winds picked up a little bit along with a small amount of snow. ill try loading some more like this and some lighter loads and get a flag out there for next time. thanks for the help guys.
i noticed a few of the shots were dead on to where i wanted them to be and some werent so im hoping the wind played its part the other day and it wasnt completely my loads.
Click to expand...

As well as some wind flags or indicators...

Put up a mirage board, alternating horizontal black and white stripes above your target maybe on a piece of card stock 15 by 15 inches. The stripes 1.5" thick and apart. This will show you the mirage which can indicate the air flow. Shooting when the mirage is in opposite directions can give dispersions you indicate.

NormB
 
It's gotta be a combo of you and your loads, run the numbers in JBM, you need 10mph of wind to blow you over 3 inches at 200 yards using the amax at 2700. Maybe have someone else test your gun?
 
Wind affects the bullet. Simple as that. If the shooter does not compensate, there will be lateral dispersion.
What was the vertical spread? That should tell you something.
 
well i had my buddy shoot the gun but im a much better shot than he is. the wind at some point was strong enough to tip over the porta crapper thats at the range.

i used my bi pod, pre loaded it for the first time, which could have affected the groups as well if the same amount of pre load wasnt applied, and since i forgot my rear bag at home i used my plastic ammo box to stabilize the rear of the gun. i could very well be the problem, i just know that last time out i shot much tighter groups at 100y without anything under the rear of the gun but i didnt get to shoot out to 200 last time. theres a local ex military sniper that works at our range ill have to find him next time out and get him to put some down for me.

it was more a drop than anything. the bullet was only about 1 inch off center but had dropped about 2.5 inches. if it were the wind id guess it would be the wind coming down over the berns that caused it. likely though the load more than anything else. ive shot the gun much tighter with factory ammo out to 200 but never on a day that had this much wind, combined with snow this time around.

ill bring out some other friends that shoot well next time or get one of the rso's to put some down and see what they can do. a flag for my next trip is a must for sure. i didnt even think about this but ive got a box of factory ammo in my range bag i should have shot to compare it to.
 
Too many variables changing at once. Shooting in a steady wind blowing in a consistent direction is one thing. Shooting in a gusty wind that is changing direction is another.
 
ill load some similar loads when my new batch of bullets arrive and ill try again.
ill blame it on the wind and the fact i didnt drink enough rickards red the night before to steady my hands in the morning, lol
 
yeah thats true. i think the berms were really throwing it around all over the place. the flag was wet and partially frozen at the shooting tables, the red flag to indicate a hot range so it was no use. ill get some ribbons or something and set up an indicator next time out
thanks for the help guys
 
I don't shoot .30 cal anymore but 3 inches at 200 is correct for a 10mph full value wind.
200 x 10 =2000. Drop the zeroes=20/13=1.53. 1.53x 2(200yd) =3.06" drift @ 200yds for 10 mph full crosswind.
 
last times I went to the range there was a strong wind and all I did is hit the target everywhere, and run after my loose targets in the wind....
 
The wind at the firing line is more critical than the wind at the target. If the wind is gusting, choose to either shoot in the lull or the gust. If the wind is swapping directions, try to predict when there is a neutral wind and shoot on it. If I understand the description of your range correctly, the high sides could result in very turbulent air on the range which could be tricky to figure out.

If you don't have a wind meter, get the wind from your local radio station, or use a wind flag. If there are wind flags at the range, divide the angle between the tip of the flag and the flag pole by 4, that will give you the wind speed in MPH, and is useful up to about 25 mph in which case the flag will rize above the horizontal; a wind above 25 mph is too difficult to read by the flag. A field expedient wind flag can be made by holding a rag at shoulder height with your arm fully extended. Let the rag go and point to the spot where it hits the ground. The angle between your arm and your body is dived by 4 to determine the wind speed in mph.

To determine your bullet's drift with a .308 or a .30/06, divide the range by 100 and mulitply by the wind speed in mph. Divide this number by 15 to determine your drift in MOA. As range increases beyond 500 yards the constant is reduced by 1 for each 100 yards of range. But in your case, with a 10 mph wind and a 200 yard target, 2X10=20, 20/15=1.3 MOA, 1.3@ 200= 2.6".
 
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