Wm.Traynor wrote:As an aspiring marksman 60 years ago, I devoted myself to a study of a book by Jim Sweet**, a multi- Queen's Prize winner. He listed the differences in allowances, for winds coming from various positions on the clock-face, relative to the shooter. It did my brain in, especially at first but it gave me a general idea which I persisted with over the years. Towards the end of my career I would simply memorise the allowance for for each direction, at the distance I was shooting at the time. Changes in strength would throw those calculations overboard Even further toward the end, I made every shot a sighter, which for me, worked well...................................mostly, until it didn't
But one piece of advice that I have never forgotten came from my Club Champion of the time. "Keep one eye on the sights, one eye on the flags and the other eye on the mirage". "It's that easy, Bill", he said with a grin.
** "Competitive Rifle Shooting"(?) It's so long I have forgotten
Needless to say, none of this is meant to detract from the efforts of bladeracer to start a discussion on this subject. Good on him, in fact, because it should lead to a greater understanding of this vexing and humiliating subject.
Wm.Traynor wrote:Wind speed was measured in knots. I am not up to speed (pun intended) with modern nomenclature.
If you want to see mirage, focus on an object closer than the target with your spotting scope. Focus at shorter distances to see what it is doing overall, if you have only one sheet/wind indicator. FWIW, I only resorted to watching mirage when the flags were pointing in different directions at different ranges.
Good Luck
Biscuits wrote:I had an interesting trip to a range I had not been to previously, over the weekend. The firing point is on a ridge, therefore you shoot down into the ground below. Unlike a range on flat ground, here you shoot from an elevated position and all the ground in front if you is lower. Multiple steel targets from about 150 metres to 1000 metres. Although the ground in front of the ridge is lower, it still isnt flat, there are other lower ridge lines parallel to the firing point so the ground is undulating. Targets are small in the horizontal direction, about 1.2 MoA wide.
The wind at the firing point was low-moderate from 90 to around 150 degrees variable, ie from direct crosswind from my right to a rear quartering wind.
Had first shot hits on all targets up to about 600m, followed on the next target by a first shot miss. Made corrections and was able to hit all further targets to 1000m, some on first shot, some on second, one took 5 shots. The ground was grass, neither spotter nor myself could not see any impacts from the miss. Directs hit on the on the steel target only were visible. So the 5 shot target I had to shoot in a grid around the target until it hit it and could see the impact of a hit; if the ground had been different and I had been able to spot the misses, I probably would have hit that particular target on the 2nd rather than 5th shot. Anyway, this brings me to the reason for posting.
The firing point was at ground level but the path of the bullet once it left the high ridge of the firing point, was maybe 100 metres above ground, until it connected with the target. Wind speed is not constant with elevation. Wind speed increases with elevation... if you go to aircraft altitudes, it can be quite normal to have a 200mph wind. The standard height for reporting wind speeds which you see in the weather forecast is 10m above ground level. However you usually shoot from the ground, the wind speed will be less than at the reference 10m height. In my case, as soon as the bullet left the barrel, it was off the ridge and then 50 or 100m high above the ground below. Higher up, where the wind is stonger.
The misses i had were because I did not dial in enough wind. I did not dial in enough wind as I had mistakenly calculated for the wind at the firing point being constant downrange, whereas most of the trajectory of the bullet was high above the ground, so it had a much higher wind on it.
On the elevation side, a head or tail wind (or head/tail wind component if it is not coming exactly 0 or 180 degrees) will also affect elevation, not that much, but a bit. I believe the reason I was dialling 10.3 millirad of elevation at the 1000m target instead of 10.6 millirad which my calculator was telling me, was due to the tailwind component.
bigrich wrote:I don’t need flags or strips of bedsheet, I watch the birds. If a crow is going in a 45 degree angle to the direction he’s flying in , just go home and have a beer
Biscuits wrote:I had an interesting trip to a range I had not been to previously, over the weekend. The firing point is on a ridge, therefore you shoot down into the ground below. Unlike a range on flat ground, here you shoot from an elevated position and all the ground in front if you is lower. Multiple steel targets from about 150 metres to 1000 metres. Although the ground in front of the ridge is lower, it still isnt flat, there are other lower ridge lines parallel to the firing point so the ground is undulating. Targets are small in the horizontal direction, about 1.2 MoA wide.
The wind at the firing point was low-moderate from 90 to around 150 degrees variable, ie from direct crosswind from my right to a rear quartering wind.
Had first shot hits on all targets up to about 600m, followed on the next target by a first shot miss. Made corrections and was able to hit all further targets to 1000m, some on first shot, some on second, one took 5 shots. The ground was grass, neither spotter nor myself could not see any impacts from the miss. Directs hit on the on the steel target only were visible. So the 5 shot target I had to shoot in a grid around the target until it hit it and could see the impact of a hit; if the ground had been different and I had been able to spot the misses, I probably would have hit that particular target on the 2nd rather than 5th shot. Anyway, this brings me to the reason for posting.
The firing point was at ground level but the path of the bullet once it left the high ridge of the firing point, was maybe 100 metres above ground, until it connected with the target. Wind speed is not constant with elevation. Wind speed increases with elevation... if you go to aircraft altitudes, it can be quite normal to have a 200mph wind. The standard height for reporting wind speeds which you see in the weather forecast is 10m above ground level. However you usually shoot from the ground, the wind speed will be less than at the reference 10m height. In my case, as soon as the bullet left the barrel, it was off the ridge and then 50 or 100m high above the ground below. Higher up, where the wind is stonger.
The misses i had were because I did not dial in enough wind. I did not dial in enough wind as I had mistakenly calculated for the wind at the firing point being constant downrange, whereas most of the trajectory of the bullet was high above the ground, so it had a much higher wind on it.
On the elevation side, a head or tail wind (or head/tail wind component if it is not coming exactly 0 or 180 degrees) will also affect elevation, not that much, but a bit. I believe the reason I was dialling 10.3 millirad of elevation at the 1000m target instead of 10.6 millirad which my calculator was telling me, was due to the tailwind component.
Blr243 wrote:How much distance does a brutal 90 degree wind push a 3000 FPS 130 270 pill at 200 m distance ? Not exact please , I pulled these figures out of the air
Wm.Traynor wrote:That is about right, bladeracer.
Blr243 wrote:Blade, are you saying in a bad wind at 200 m there could be 10-12 inches of poi change ? If so that’s a fair bit more than what I expected. Fortunately I don’t encounter wind like that in the field and I do my best to be perfectly downwind of my game .....but it’s still good to be mindful of its effect on bullet flight.
Johnno wrote:Not many shooters at all have rifles that have achieved a true no wind zero for a starting point. It's usually always either one or several clicks up to no good and it's very hard to get it right without using an indoor range, preferably for 100 m, and there there are no such ranges in my home state SA, to my knowledge.
You'd need that no wind zero to calculate the wind effect using an app such as Strelok, and then combine the info using the flags at the range. Notes or a good memory are essential.
I would gladly pay big money to use an indoor range to sight my rifles in. 200m would be a dream. Then you'd really know what your rifle is capable of.
Johnno wrote:Sako guarantees that their rifles will produce 30mm at 100m “out of the box”. To make sure they do, Sako test fires every rifle on their 100m indoor range before it leaves the factory. They have eliminated the wind factor there and these guarantees sell a lot of rifles as you wouldn't buy an expensive rifle unless there is some proof as to what it can do under ideal conditions.
Your load development or factory ammo selection after the purchase would likewise be best tested indoors over say 100m. When you then go outdoors, you will be starting to read the wind from a more accurate level.
The method of reducing the distance such as down to 10 metres to achieve a zero outdoors has merit as it may be the best thing to do under the circumstances but it is not a true zero. The errors will be magnified ten times or more over 100m. Most rifles are not zero wind tuned and the groups they produce would usually be tighter indoors. To constantly adjust the windage knob also wears out the mechanism quicker and I usually only use reference points rather than adjusting the windage.
bladeracer wrote:I was making some notes and decided I might as well share for comment
For anybody interested in learning about wind holds, you need some sort of consistent wind indicator, heavy enough that it doesn't whip all around, but not so heavy that it only swings an inch in a 10mph wind. A four-foot strip of four-inch wide bed sheet works well for me, as it is readily replaced (assuming you kept the rest of the sheet you tore it off), and virtually free. I keep sheets for covering machinery when I'm working on something.
Head and tail winds do affect the bullet, but the biggest effect is crosswind. Crosswind doesn't relate to the actual speed of the wind though, only the speed at which the wind crosses your line of fire, regardless of its actual direction. If you're shooting in a 20mph wind but it's coming over your right shoulder from five-o'clock, it's probably only applying a 5mph crosswind to your bullet, or less. The different effect on the bullet is dramatic between 20mph and 5mph. It's good to know the wind speed and direction, but what you really need to know is the wind speed perpendicular to your line of fire. It's better to know the wind at your firing position rather than at the target, but it's more difficult to watch a wind flag a meter in front of you, as well as focus on a target 200m away. If you can place wind flags along the line of fire, do so as you'll see exactly what the wind is doing, but good luck trying to plot a flight path through it
Remember physics too. A bullet travels straight unless a force (wind) acts upon it to change its direction. When that force is released it goes back travelling straight again, but now in the direction it's going when that force stops. A 50mph gust of wind for a hundredth of a second has less effect on the bullet than the 5mph wind that is constant over the other 99-hundredths of the second it's in flight.
Set your "flag" up directly above a gong a little bigger than the rifle can group. Zoom in enough that you can see the target, and the wind indicator. Shooting with both eyes open is good also, but I think most people struggle on high magnification. 18-power takes a little settling into for me, lower powers are easier to superimpose your sight picture over the world view. I really can't shoot both eyes open through a scope with my left eye at all.
Then get some bricks of ammo (which is why I highly recommend practicing with .22LR a _lot_), and concentrate on the flag, more than your sight picture. Fire a few rounds _only_ when the flag drops to completely vertical, and zero your sights to drop your bullets on your point of aim at that point, at least in the vertical. You can worry about head/tail winds affecting your elevation later. Then take a sight picture, but focus on the flag. If it regularly drops vertical you can simply wait (a lot) and fire when it does, with no wind hold.
Because .22LR is so much cheaper than your 6.5mm stuff, you can afford to play around with the flag and learn stuff. When the flag is just off vertical, say 100mm out from the pole you probably won't need any wind hold out to 200m. When the flag is 300mm out from the pole you might want a 50mm hold. When the flag is hanging at 45-degrees (a 1400mm flag would be 1000mm out from the pole), you might want a 100mm hold. When the flag is lying horizontally you might need a 200mm hold, or more.
It depends a lot on your specific wind indicator. Mine for example is horizontal at 10mph, so anything higher has zero visual effect on the flag.
If you shoot competition, I suggest getting the same flag your club uses. If that's not possible I would take your flag in, set it near theirs, and see how yours compares to theirs for future reference.
If anybody would like correct, clarify or add anything please do. I'd love to see more people playing with their .22's at longer ranges
in2anity wrote:bladeracer wrote:I was making some notes and decided I might as well share for comment
For anybody interested in learning about wind holds, you need some sort of consistent wind indicator, heavy enough that it doesn't whip all around, but not so heavy that it only swings an inch in a 10mph wind. A four-foot strip of four-inch wide bed sheet works well for me, as it is readily replaced (assuming you kept the rest of the sheet you tore it off), and virtually free. I keep sheets for covering machinery when I'm working on something.
Head and tail winds do affect the bullet, but the biggest effect is crosswind. Crosswind doesn't relate to the actual speed of the wind though, only the speed at which the wind crosses your line of fire, regardless of its actual direction. If you're shooting in a 20mph wind but it's coming over your right shoulder from five-o'clock, it's probably only applying a 5mph crosswind to your bullet, or less. The different effect on the bullet is dramatic between 20mph and 5mph. It's good to know the wind speed and direction, but what you really need to know is the wind speed perpendicular to your line of fire. It's better to know the wind at your firing position rather than at the target, but it's more difficult to watch a wind flag a meter in front of you, as well as focus on a target 200m away. If you can place wind flags along the line of fire, do so as you'll see exactly what the wind is doing, but good luck trying to plot a flight path through it
Remember physics too. A bullet travels straight unless a force (wind) acts upon it to change its direction. When that force is released it goes back travelling straight again, but now in the direction it's going when that force stops. A 50mph gust of wind for a hundredth of a second has less effect on the bullet than the 5mph wind that is constant over the other 99-hundredths of the second it's in flight.
Set your "flag" up directly above a gong a little bigger than the rifle can group. Zoom in enough that you can see the target, and the wind indicator. Shooting with both eyes open is good also, but I think most people struggle on high magnification. 18-power takes a little settling into for me, lower powers are easier to superimpose your sight picture over the world view. I really can't shoot both eyes open through a scope with my left eye at all.
Then get some bricks of ammo (which is why I highly recommend practicing with .22LR a _lot_), and concentrate on the flag, more than your sight picture. Fire a few rounds _only_ when the flag drops to completely vertical, and zero your sights to drop your bullets on your point of aim at that point, at least in the vertical. You can worry about head/tail winds affecting your elevation later. Then take a sight picture, but focus on the flag. If it regularly drops vertical you can simply wait (a lot) and fire when it does, with no wind hold.
Because .22LR is so much cheaper than your 6.5mm stuff, you can afford to play around with the flag and learn stuff. When the flag is just off vertical, say 100mm out from the pole you probably won't need any wind hold out to 200m. When the flag is 300mm out from the pole you might want a 50mm hold. When the flag is hanging at 45-degrees (a 1400mm flag would be 1000mm out from the pole), you might want a 100mm hold. When the flag is lying horizontally you might need a 200mm hold, or more.
It depends a lot on your specific wind indicator. Mine for example is horizontal at 10mph, so anything higher has zero visual effect on the flag.
If you shoot competition, I suggest getting the same flag your club uses. If that's not possible I would take your flag in, set it near theirs, and see how yours compares to theirs for future reference.
If anybody would like correct, clarify or add anything please do. I'd love to see more people playing with their .22's at longer ranges
Blade respectfully gonna have to disagree with your statement that "Head and tail winds do affect the bullet, but the biggest effect is crosswind" - in fact quite the opposite. The worst wind to deal with is a fishy head or tail wind - just ask any competitive target shooter (either TR or F-class) and they will tell you the same. In fact it's basic coaching when you get into these disciplines.
The reason is to do with the "factor" which is applied during calculation (considering the wind is always fluctuating).
Lets do an example:
A three oclock direction has the highest factor of 4 in a calculation which is made up of three parts, A) strength B) direction C) distance. Multiply the relevant coefficient values together and you will have your windage adjustment.
A two oclock wind is a factor of 3.5. A four oclock wind also has a factor of 3.5. Now, if the wind fluctuates between 2 and 4 oclock (which is quite reasonable), the effect will be minimal. The further you go around the dial toward 12oclock or 6 oclock, relatively speaking the more profound the change in factor.
If the wind was coming parallel to the shooter, any small change has a huge effect on POI.
Lets take another example:
A one oclock headwind has a factor of 1 (i.e 1x the other two factors). If the wind fluctuates to two oclock the direction factor jumps to 2, meaning your windage adjustment suddenly DOUBLES in an instant. If it moves to the twelve oclock, suddenly you have no windage whatsoever because the factor is zero, which multiplies the other two factors out to zero.
In summary, contrary to what seems logical, a perpendicular crosswind is in fact easier to deal with than parallel, considering the wind is never a constant direction.
If you want to learn more, I suggest reading this fullbore guide: https://cdn.shopify.com/s/files/1/0056/ ... 51b405.pdf
bladeracer wrote:I agree completely that a head/tail wind can be devilishly frustrating and difficult to read, but I don't agree that it has a greater effect on point of impact at the target. I'm sure a 10mph full-value crosswind will move your bullet further from your point of aim than a 10mph headwind will.
Blr243 wrote:I tend not to shoot little game and it’s usually up close. Is there anyone else here who has never had to consider the strength of the wind prior to a shot in three decades of hunting? I have only ever paid attention to its direction to ensure I’m not detected
in2anity wrote:bladeracer wrote:I agree completely that a head/tail wind can be devilishly frustrating and difficult to read, but I don't agree that it has a greater effect on point of impact at the target. I'm sure a 10mph full-value crosswind will move your bullet further from your point of aim than a 10mph headwind will.
Obviously a perpendicular crosswind will move the bullet the most, but a fluctuating perpendicular is much less damaging to your group compared with the same wind come from a parallel direction. A perpendicular is also easier to observe, either in the form of the flag, or the mirage or even the dust splash or vegetation if you're really out of options.
Blr243 wrote:I tend not to shoot little game and it’s usually up close. Is there anyone else here who has never had to consider the strength of the wind prior to a shot in three decades of hunting? I have only ever paid attention to its direction to ensure I’m not detected
in2anity wrote:Blr243 wrote:I tend not to shoot little game and it’s usually up close. Is there anyone else here who has never had to consider the strength of the wind prior to a shot in three decades of hunting? I have only ever paid attention to its direction to ensure I’m not detected
The way I see things, hunters tend to go for "wind-cheating" calibers that shoot fast and flat out to reasonable distances. I have a 204 in the safe and it's very accurate to 200m with zero consideration made to the wind. A very easy to use caliber at short range. And that's how hunting rifles should be - humane.