Mile Shot

[RMulhern]

Guys this thread is about making mile shots with a new rifle, to the OP I say "congrats, job well done".

On reading your wind remember to look at markers along the full length of the shot as well as upwind. It will give you a much better read on what conditions will be through the last 1/3 of the bullet's flight which will much more influence the POI than the first 2/3.

As a rule I figure whatever wind effect there is for the first 2/3 of the flight will amount to no more than half of the total wind affect throughout the flight.

You also just have to keep in mind that wind effects are not instantaneous. You can see a gust coming across tall grass or small trees relative to your target.

The steady wind will have a steady lean on the foliage and a gust will create a visible wave you can follow and time.

WildRose

"on what conditions will be through the last 1/3 of the bullet's flight which will much more influence the POI than the first 2/3."

I disagree with that statement wholly and totally! The first 1/2 of the winds effect upon the bullets travel is the most important!

 

[steeltraps]

One could say that both of the last 2 statements are true! I think that topograph plays a great role in how the bullet is affected by the wind! At my range the other day, my flags were blowing like crazy. 8 to 10 mph. I started shooting at 1700 yards at rocks . I was using like 7 moa of wind hold. I ended up using only 4 moa at 2342 yards. 2342 is the fartherest i have ever shot my 338 lapua. The point is wher i shot the mountain breaks of in to fingers, even though my wind flags where the same, as i progressed left down the mountain the wind or lack of it caused me to use almost no wind calls. The wind at my end never changed just the topograph of the land!gun)

 

[ccsykes]

Must be nice to have all those areas to see splashes. The wind and drizzle were so bad you couldn't keep the spotting scope still enough to watch trace.

 

[steeltraps]

The rocks we shoot at are large,white,flat rocks!!! The only thing is they HAVE to be dry. If you shoot them when they are wet you will see 0 splash!! When they are good and dry they make a small puff of white dust come up! We have to drive 90 miles to ower main target area so we pick days that are good for our type of shooting. We wait till afternoon, but not to late, to shoot. We never shoot unlesss it hasnt rain for at least 4 days!gun)

 

[ccsykes]

We shoot in all conditions. Mud, rain, wind, heat, not much stops us.

 

[WildRose]

WildRose

"on what conditions will be through the last 1/3 of the bullet's flight which will much more influence the POI than the first 2/3."

I disagree with that statement wholly and totally! The first 1/2 of the winds effect upon the bullets travel is the most important!

You're free to disagree but all you have to do is plot it out on a chart and you will see that the bulk of the effect shows up on the last 1/3 of the flight assuming the same conditions throughout the flight.

Once the bullet slows down the wind has more time to affect it and of course the bullet begins slowing as soon as it leaves the end of the barrel and the rate at which speed drops increases with range.

Ballistics Calculator - Hornady Manufacturing, Inc

 

[ccsykes]

This post is not a wind discussion or the sorts. A new thread should be started on that. I was merely stating I shot a target in high gusts cold bore at a mile. Wind was unreadable due to terrain and conditions.

 

[WildRose]

This post is not a wind discussion or the sorts. A new thread should be started on that. I was merely stating I shot a target in high gusts cold bore at a mile. Wind was unreadable due to terrain and conditions.

Threads tend to evolve after a couple of pages, no one is dissing your accomplishment.

The way I read your op, you did a hell of a job reading the wind considering the conditions.

 

[RMulhern]

You're free to disagree but all you have to do is plot it out on a chart and you will see that the bulk of the effect shows up on the last 1/3 of the flight assuming the same conditions throughout the flight.

Once the bullet slows down the wind has more time to affect it and of course the bullet begins slowing as soon as it leaves the end of the barrel and the rate at which speed drops increases with range.

Ballistics Calculator - Hornady Manufacturing, Inc

The ONLY TIME the 'theory' of the Ballistics Calculator would be remotely true is if there were obstructions of terrain at the first half of the distance fired whereby conditions at the last half were clear such as firing across an open valley! The more the bullet is moved off course during the first half of it's flight will be more under normal range conditions without any obstructions! And every long range champion that has ever won a national championship at Camp Perry would tell you the same thing I'm preaching to you!!

 

[ccsykes]

That makes little sense. Wind striking a bullet closer to muzzle, even if it moves it slightly due to sheer velocity, has an effect down range. Wind will move the same projectile more closer to target due to lack of velocity. Both affects dictate where the target is strict. Understanding how derivations are used in the algorithm of ballistic calculators takes this into account. The third derivation from an acceleration equation gives positional data.

 

[Canadian Bushman]

Ive run these numbers on sierra infinity software using the info from my 308 shooting a 185gn bullet at 1000 yds.
All winds are full value from right to left and spin drift is excluded.

The wind drift for a 3mph wind the entire distance is 2.5 moa

The wind drift for a 3mph wind the last 500 yds is .8 moa

The wind drift for a 3mph wind the first 500 yds is 1.6 moa.

The first half of the distance accounts for aprx 2/3's of the entire drift.

 

[ccsykes]

CB, one could argue the physical distance the bullet is pushed in the first 500 is less and the deviation of path is what causes the larger appearing wind effect. Physics says that wind will have a greater effect on a slower moving object of equal mass.

 

[Canadian Bushman]

CB, one could argue the physical distance the bullet is pushed in the first 500 is less and the deviation of path is what causes the larger appearing wind effect. Physics says that wind will have a greater effect on a slower moving object of equal mass.

It wouldnt be an argument. That is what's happening.

 

[WildRose]

CB, one could argue the physical distance the bullet is pushed in the first 500 is less and the deviation of path is what causes the larger appearing wind effect. Physics says that wind will have a greater effect on a slower moving object of equal mass.

Didn't mean to turn this into some sort of idiotic ******* contest.

Using 180gr projectile 3250fps .590G1 BC full value 10mph wind.

Wind drift in inches.


100yds .4

200yds 1.7

300yds 3.9

400yds 7.1

500yds 11.4

600yds 16.8

700yds 23.5

800yds 31.5

900yds 41

1000yd 52".

The longer the projectile flies, the slower it gets and the wind has a greater effect on it as a result when comparing the same 100yds interval.