Ghostiger7
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learn to read the mirage:)
SHOOTERS : Doping Wind?
- Thread starter skeeter
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Gewehrsmann
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Jab, that was an excellent discussion on wind.
Skeeter, there is a mathematical formula for wind. Using the techniques discribed by JAB to determine the speed and direction, the formula is:
Range X Wind Velocity/10 this will give you the amount of minutes of windage adjustment to apply to your scope. I am going off memory here and am over 30, so my memory might be off but this is the formula taught us back in the day using the M21 so the round would have been the 7.62 and white box match which I think was the 175 grain FMJ.
Skeeter, there is a mathematical formula for wind. Using the techniques discribed by JAB to determine the speed and direction, the formula is:
Range X Wind Velocity/10 this will give you the amount of minutes of windage adjustment to apply to your scope. I am going off memory here and am over 30, so my memory might be off but this is the formula taught us back in the day using the M21 so the round would have been the 7.62 and white box match which I think was the 175 grain FMJ.
Gewehrsmann
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You can use other numbers as the denominator such as 15 for a fast sleek round like the 6.5 x 284. You will need to experiment around a bit but once you have a load and formula you should be good to go. You might also look at some of the score books and other data sources that the high power shooters use. They have charts and diagrams on the back cover which might be helpful.
These techniques will only get you close to develop any level of expertise it will take thousands of rounds of practice and varying ranges and wind conditions.
These techniques will only get you close to develop any level of expertise it will take thousands of rounds of practice and varying ranges and wind conditions.
skeeter
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Well... I'm using a .308 and have gotten a set of comp dies from RCBS. My Dad and I are working on loads using 168grn. and 175grn. serria HPBT matchkings. We go out along with Frisco this weekend maybe out to 600yds. Wish us luck;)
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Here's the only formula I use- The Short Wind Formula
This is used for determining MIL HOLDS which I believe to be superior to dialing (but don't forget to dial spin drift beyond 600m) and more combat relevant because they are faster and allow the shooter or spotter to make changes on the fly as conditions change...
.308 (M118LR)
1. Take the range and put a decimal after the 3rd digit ex. 300m becomes .3/ 350m becomes .35
2. Think of your wind in 4 mph blocks. 4 mph=1, 8mph=2, 12mph=3, etc...
3. Multiply your range decimal by the wind blocks.
ex. 300m target with 4 mph wind range=.3 wind=1 .3 x 1 = .3 mil hold
ex2. 450m target with 6 mph wind range=.45 (I'd round to 5 because I'm not that smart) wind= 1.5 .5x1.5= .7 mil hold.
Do it a couple times on the range, you'll find it to be VERY accurate!!!
For Mk262/.223, use 3 mph per wind block
For A131/.300 use 5 mph
This is used for determining MIL HOLDS which I believe to be superior to dialing (but don't forget to dial spin drift beyond 600m) and more combat relevant because they are faster and allow the shooter or spotter to make changes on the fly as conditions change...
.308 (M118LR)
1. Take the range and put a decimal after the 3rd digit ex. 300m becomes .3/ 350m becomes .35
2. Think of your wind in 4 mph blocks. 4 mph=1, 8mph=2, 12mph=3, etc...
3. Multiply your range decimal by the wind blocks.
ex. 300m target with 4 mph wind range=.3 wind=1 .3 x 1 = .3 mil hold
ex2. 450m target with 6 mph wind range=.45 (I'd round to 5 because I'm not that smart) wind= 1.5 .5x1.5= .7 mil hold.
Do it a couple times on the range, you'll find it to be VERY accurate!!!
For Mk262/.223, use 3 mph per wind block
For A131/.300 use 5 mph
OUTSTANDING JAB. Skeeter, after determining value and velocity, you apply the forumla given above. However, keep in mind there are constants based on range for the formula. There may be other math-tacs to use, but I have tested this formula with constants out to 1000 yards with up to 18 mph full values. I train under Marine Scout Sniper and Army B4 Steve Suttles. They run a great 4-week POI. I have two more weeks of schools to finish under him (we use up to a 6 week sniper POI on our Team, but we don't have the luxury of attending the training in one lump so we complete it in week phases). He is an outstanding teacher and awesome at wind calls. I just completed a phase including KD and UKD (100-1000 yards) with INSANE winds. So I got schooled! LOL
Suttles advice: PRACTICE PRACTICE PRACTICE. He says throughout your normal day activities, watch the environment and practice calling wind. Go out to the ranges or fields or cities and watch mirage through your spotting scope to get better. My first recommendation is to get you a spotter under these conditions. It helps save rounds. LOL I came from a SWAT sniper background before going to long range school and we RARELY use spotters on call-outs. This is generally because real time operational deployments rarely afford the luxury of you and your spotter arriving on scene at the same time. But after working with spotters extensively at these schools, I wish I could keep a spotting trunk monkey in my car. LOL Anyhow, here is what we use.
Range (100s) X Velocity (MPH) DIVIDED BY Constant = MOA Full Value
------------------------------------
Constants:
100 to 500 yards - 15
600 yards - 14
700 to 800 yards - 13
900 yards - 12
1000 yards - 11
I wouldn't have thought the constants would have made THAT much of a difference in my ignorant days (still in those days too =), but they do at extended ranges. If its a half value, of course just split the MOA. You always have MIL lead cheats too, and there is DOPE out there you can use as a guideline to start comparing. But of course you will have to figure out what your baby likes. I go to my next phase with moving targets at extended ranges with more INSANE wind the first week of November, so I will share that experience when I get back. Be safe brother.
Suttles advice: PRACTICE PRACTICE PRACTICE. He says throughout your normal day activities, watch the environment and practice calling wind. Go out to the ranges or fields or cities and watch mirage through your spotting scope to get better. My first recommendation is to get you a spotter under these conditions. It helps save rounds. LOL I came from a SWAT sniper background before going to long range school and we RARELY use spotters on call-outs. This is generally because real time operational deployments rarely afford the luxury of you and your spotter arriving on scene at the same time. But after working with spotters extensively at these schools, I wish I could keep a spotting trunk monkey in my car. LOL Anyhow, here is what we use.
Range (100s) X Velocity (MPH) DIVIDED BY Constant = MOA Full Value
------------------------------------
Constants:
100 to 500 yards - 15
600 yards - 14
700 to 800 yards - 13
900 yards - 12
1000 yards - 11
I wouldn't have thought the constants would have made THAT much of a difference in my ignorant days (still in those days too =), but they do at extended ranges. If its a half value, of course just split the MOA. You always have MIL lead cheats too, and there is DOPE out there you can use as a guideline to start comparing. But of course you will have to figure out what your baby likes. I go to my next phase with moving targets at extended ranges with more INSANE wind the first week of November, so I will share that experience when I get back. Be safe brother.
Wow I have not been back here in a while….. Etype and Mic good stuff, the only thing I would add is that your constants will change based on your ammunition velocity. In a basic term the more bullet velocity you lose the lower amount your constant will become. However, when shooting at 1000yds and in some ammunition will allow a straight constant such as using M118, M118LR, and M852 the constant is 10 at all ranges.
Skeeter, with the ammunition you are running you will be GTG using a constant of 10, so the math is the distance times the wind speed divided by 10 giving you the MOA for adjustment. For example 5MPH full value wind speed at a distance of 200 yards (2x5=10/10 = 1MOA) so your adjustment would be 1 MOA into the direction of the wind.
Skeeter, with the ammunition you are running you will be GTG using a constant of 10, so the math is the distance times the wind speed divided by 10 giving you the MOA for adjustment. For example 5MPH full value wind speed at a distance of 200 yards (2x5=10/10 = 1MOA) so your adjustment would be 1 MOA into the direction of the wind.
Another option (if you’re not running a mil-dot optic) for closer ranges such as 200 to 500 yards is using aim points, for instance taking the target and breaking down into hold off points. Breaking down the human size target into 4 inch blocks as seen in the picture.
skeeter
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Thanks for the info guys! I haven't been able to go out past 300 yds yet because I don't feel my scope adjusts correctly. I just don't want to waste the ammo. I picked up a set of Night Force 20 MOA bases and put them on. I've also worked with dad and my rifle loves 168grn hornady A-max bullets with 42 grains of Re-loader 15 packed into Winchester brass. We also have great loads with 175 and 190 grn Serria Matchkings. I've been hanging out at the local 1000 yard matches and talking to shooters about wind. Whenever I upgrade my scope I'll get out there and try myself.
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Out to 300 you should be using hold overs, I'd say. Dialing is too time consuming for combat use unless you're firing a long range, uncompromised, deliberate shot. After bullets start flying, or on a short shots (600 and in) you should be able to do a quick mil (or guess, my favorite) then send it with a mil hold.
