Wind at 100yards

[TattooedGun]

So my gf was asking whilst we were on SS on saturday if the wind at 100 yards made a difference..

Both me and her mom said at 100 yards not really...

was that true?

It wasnt really windy there so for our purposes then I'd imagine its not far wrong, but given enough wind at 100 yards, surely it could adjust the trajectory of the bullet, how much? 1/4min, 1/2min, 1 min? how much wind?

When doing load development do you try and compensate for the wind? or shoot when there visibly is none?

[Robin128]

Wind makes a difference at any range.

It makes quite a difference if it is gusting as opposed to just constant.

Ideally work up your rounds in still weather.

[Dangermouse]

You have to remember two things,

Firstly, Short Siberia is a very sheltered range with the 100 yard having a tree line along the left hand side, so on this 100 yards you were not affected by the wind much.

Secondly, you were using open sights and you accept that your groups size reflected this. Had you been using a scope then your expectations would be much higher.

If I very quickly use a ballistics program I find a 155gn .308 cal travelling at 2800 fps will move .53" in a 10mph wind. More Alarmingly, it will move 2.19" at 200 yards.
As I say, for some people that amount is a lot,

DM

[TattooedGun]

Thanks for the swift replies :)

DM the numbers stated are about what I was thinking... the 200 yard one was a little bit alarming as you say, but it is to be expected... a constant wind accross the bullets flight will be pushing it over from the end of barrel to point of impact...

the bit that baffles me is how much affect the wind has, even though the bullet is travelling 1909.09mph when it comes out the end of the rifle, a 10mph wind still has that much affect on it...

I definately need to pick up a book on ballistics trajectories and applied ballistics... it fascinates me, but i do kind of get it!

[Christel]

Mr Litz is the man.

http://www.appliedballisticsllc.com/

I understand nada but the clever heads on here say this is the book to read.

[Dangermouse]

http://www.appliedballisticsllc.com/

The book to buy,

DM

[ovenpaa]

Litz is a good reference, I am still on the first edition however I hear good things about the second edition. There some other good books on wind reading and a link somewhere on here to a wind rosette created by an Aussie that is very good for .308 TR shooters, he is also a forum member.

[Christel]

DM, I beat you to it :)

Must be my super sonic approach to life.

[Dangermouse]

You did Christel, but I am still smiling at being put in the clever heads catagory :lol:

DM

[Christel]

Hey You are, definitely. If you can understand what that guy says...clever heads category!